Athletic performance
Supplements studied for athletic performance.
Overview
SupplementDEX indexes 49 supplements for athletic performance across 461 studies—the largest evidence base in this batch.
Creatine monohydrate has the strongest rating (WA 88, very high across all dimensions), with consistent benefits for short-burst strength and power in sports such as rowing, jumping, and soccer. Caffeine (WA 88; high effect size, very high evidence, very high trust) reliably improves performance, endurance, and strength, with effects varying by body weight and habitual intake. Whey Protein (WA 76; high effect size, high evidence, medium trust) supports muscle strength and size when combined with training.
Beta-Alanine (WA 68; medium effect size, very high evidence, medium trust) may improve high-intensity endurance lasting one to four minutes after weeks of daily use. L-Citrulline (WA 68; medium effect size, very high evidence, medium trust) shows mixed aerobic benefits but may reduce fatigue and soreness at higher pre-exercise doses. See the heatmap and evidence reviews below for all 49 supplements.
Effect graph
Relevant supplements
Relevant supplements sorted by DEX Score.
| Creatine | ★★★★★ | High |
| Caffeine | ★★★★★ | High |
| Whey Protein | ★★★★★ | High |
| Ashwagandha | ★★★★★ | Medium |
| Rhodiola | ★★★★★ | Medium |
| L-Citrulline | ★★★★★ | Medium |
| Beta-Alanine | ★★★★★ | Medium |
| Acetyl-L-Carnitine | ★★★★★ | Medium |
| Taurine | ★★★★★ | Low |
| Branched Chain Amino Acids (BCAAs) | ★★★★★ | Low |
| Tongkat Ali | ★★★★★ | Low |
| Phosphatidylserine | ★★★★★ | Low |
| Iron | ★★★★★ | Low |
| Green Tea | ★★★★★ | Low |
| Astaxanthin | ★★★★★ | Low |
| Yohimbe | ★★★★★ | Low |
| Vitamin K | ★★★★★ | Low |
| Theanine | ★★★★★ | Low |
| Reishi | ★★★★★ | Low |
| Panax Ginseng | ★★★★★ | Very Low / None |
| Nicotinamide Riboside | ★★★★★ | Low |
| Maca | ★★★★★ | Low |
| L-Tryptophan | ★★★★★ | Low |
| Garcinia Cambogia | ★★★★★ | Low |
| Coenzyme Q10 | ★★★★★ | Very Low / None |
| Casein Protein | ★★★★★ | Very Low / None |
| Acai | ★★★★★ | Low |
| Vitamin D | ★★★★★ | Very Low / None |
| Tyrosine | ★★★★★ | Very Low / None |
| Quercetin | ★★★★★ | Very Low / None |
| Melatonin | ★★★★★ | Very Low / None |
| Magnesium | ★★★★★ | Very Low / None |
| L-Carnitine | ★★★★★ | Very Low / None |
| Glutamine | ★★★★★ | Very Low / None |
| Eleuthero | ★★★★★ | Very Low / None |
| Echinacea | ★★★★★ | Very Low / None |
| Cocoa | ★★★★★ | Low |
| N-Acetyl Cysteine (NAC) | ★★★★★ | Very Low / None |
| Kefir | ★★★★★ | Very Low / None |
| Choline | ★★★★★ | Very Low / None |
| Yerba Mate | ★★★★★ | Very Low / None |
| Vitamin B6 | ★★★★★ | Very Low / None |
| Vitamin B3 (Niacin) | ★★★★★ | Very Low / None |
| Resveratrol | ★★★★★ | Very Low / None |
| Kudzu | ★★★★★ | Very Low / None |
| Garlic | ★★★★★ | Very Low / None |
| Boron | ★★★★★ | Very Low / None |
| Apple Cider Vinegar | ★★★★★ | Very Low / None |
| American Ginseng | ★★★★★ | Very Low / None |
Studies
Find individual evidence reviews for supplements sorted by DEX Score.
49 supplements for , , and rated at least stars. All purchase bands. No minimum star filter.
CaffeineView supplement →
Proven purchase·★★★★★
How we scored this▸
- Taking caffeine prior to exercise or sport can reliably improve athletic performance, endurance and strength in most people.
- The relative benefit is dependent on various individual factors including body weight and how often one consumes caffeine on a regular basis.
Browse 67 studies·20 meta-analyses
RCTBoost or bust? A randomized crossover study on pre-exercise caffeine supplementation for fatigue management in basketball2025
In 14 amateur male basketball players, pre-exercise caffeine 3 mg/kg did not significantly affect countermovement jump, sprint times, heart rate variability, muscle soreness, or perceived fatigue versus placebo after training.
- Effect
- No Benefit
- Dose
- 3 mg/kg
- Population
- Athletes
MetaEffects of Caffeine Supplementation on Exercise Performance in Volleyball Players: A Systematic Review and Meta-Analysis2025
A 2025 meta-analysis of 11 volleyball crossover studies found caffeine improved attack and serve accuracy (SMD 0.50), single- and repeated-jump performance, handgrip strength, and agility test times.
- Effect
- Benefit
RCTErgogenic Effects of Combined Caffeine Supplementation and Motivational Music on Anaerobic Performance in Female Handball Players: A Randomized Double-Blind Controlled Trial2025
In 17 female handball players (mean age 16.7), 6 mg/kg caffeine improved countermovement jump, agility, and repeated-sprint performance versus placebo; combined caffeine plus motivational music showed the best overall results.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Female athletes
- Avg age
- 16.7±0.4
MetaEffect of caffeine ingestion on time trial performance in cyclists: a systematic review and meta-analysis2024
A meta-analysis of 15 cycling time-trial studies found moderate caffeine doses (4–6 mg/kg) significantly improved completion time (SMD −0.55) and mean power output (SMD 0.44); low doses (1–3 mg/kg) were not significant.
- Effect
- Benefit
- Dose
- 4–6 mg/kg
MetaEffects of Acute Ingestion of Caffeine Capsules on Muscle Strength and Muscle Endurance: A Systematic Review and Meta-Analysis2024
A meta-analysis of 14 studies found acute caffeine capsule ingestion significantly improved upper- and lower-body muscle strength and muscular endurance in men.
- Effect
- Benefit
- Dose
- 6 mg/day
- Population
- Men
RCTSex Differences in the Ergogenic Response of Acute Caffeine Intake on Muscular Strength, Power and Endurance Performance in Resistance-Trained Individuals: A Randomized Controlled Trial2024
In 76 resistance-trained adults (38 men, 38 women), 3 mg/kg caffeine increased bench press and back squat velocity and power at 50–90% 1RM and increased repetitions to failure at 65% 1RM similarly in both sexes.
- Effect
- Benefit
- Dose
- 3 mg/kg
- Population
- Adults
- Ages
- 18–35
RCTSupplementation of caffeine and sodium bicarbonate together could not improve performance and performance-related factors in CrossFit participants: a randomized, double-blind, placebo-controlled study2023
In 20 CrossFit participants, caffeine 6 mg/kg, sodium bicarbonate, or their combination did not improve Cindy workout performance versus placebo, though combined caffeine plus bicarbonate reduced perceived exertion.
- Effect
- No Benefit
- Duration
- 3 days
- Dose
- 6 mg/kg
- Population
- Athletes
- Avg age
- 22.3±2.88
MetaEffects of Caffeine Intake on Endurance Running Performance and Time to Exhaustion: A Systematic Review and Meta-Analysis2022n=254
A meta-analysis of 21 running trials (254 participants, caffeine 3–9 mg/kg) found caffeine significantly improved time to exhaustion (g=0.392) and modestly improved time-trial performance (g=−0.101) versus placebo.
- Effect
- Benefit
- Dose
- 9 mg/kg
- Population
- Women
- Participants
- 254
Clinical trialEffects of Multi-Ingredient Pre-Workout Supplement and Caffeine on Bench Press Performance: A Single-Blind Cross-Over Study2022n=15
In 15 resistance-trained men, anhydrous caffeine alone produced greater bench press repetition volume than a multi-ingredient pre-workout supplement containing caffeine, with no differences in perceived exertion or arousal.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Women
- Participants
- 15
- Avg age
- 5.6±3.38
MetaErgogenic Effects of Caffeine on Ballistic (Throwing) Performance: A Meta-Analytical Review2022n=151
A meta-analysis of 10 studies (151 participants) found caffeine produced a small but significant ergogenic effect on throwing performance (SMD 0.19), especially for throwing velocity at doses ≤3 mg/kg.
- Effect
- Benefit
- Dose
- 3 mg/kg
- Participants
- 151
Acute caffeine supplementation improves jumping, sprinting, and change-of-direction performance in basketball players when ingested in the morning but not evening2021
In 11 adolescent male basketball players, 3 mg/kg caffeine taken in the morning improved vertical jump, sprinting, and change-of-direction performance versus morning placebo, but evening caffeine showed no ergogenic benefit.
- Effect
- Benefit
- Dose
- 3 mg/kg
- Population
- Children
RCTCaffeine Mouth Rinse Does Not Improve Time to Exhaustion in Male Trained Cyclists2021
In 10 recreationally trained male cyclists, repeated 85 mg caffeine mouth rinses did not significantly improve cycling time to exhaustion, ratings of perceived exertion, or heart rate versus water placebo.
- Effect
- No Benefit
- Dose
- 85 mg/day
- Population
- Men
- Avg age
- ~32
RCTCYP1A2 Genotype Modifies the Effects of Caffeine Compared With Placebo on Muscle Strength in Competitive Male Athletes2021n=102
In 97 competitive male cyclists, 4 mg/kg caffeine worsened handgrip strength by 12.8% in CYP1A2 CC genotype carriers versus placebo, while AC/AA genotypes showed no significant caffeine effect on strength or vertical jump.
- Effect
- Benefit
- Dose
- 4 mg/kg
- Population
- Athletes
- Participants
- 102
- Avg age
- 25±4
MetaDoes Acute Caffeine Supplementation Improve Physical Performance in Female Team-Sport Athletes? Evidence from a Systematic Review and Meta-Analysis2021n=50
A meta-analysis of 18 RCTs in female team-sport athletes found acute caffeine improved team-sport skills (SMD 0.384), countermovement jump (SMD 0.208), total body impacts (SMD 0.488), and handgrip strength (SMD 0.395).
- Effect
- Benefit
- Population
- Athletes
- Participants
- 50
MetaEffects of Caffeine Supplementation on Physical Performance of Soccer Players: Systematic Review and Meta-Analysis2021
A meta-analysis of 16 soccer RCTs found caffeine did not significantly improve aerobic endurance distance, vertical jump, repeated sprints, agility, or perceived exertion versus placebo, though evidence quality was very low.
- Effect
- No Benefit
- Population
- Athletes
MetaErgogenic Effects of Acute Caffeine Intake on Muscular Endurance and Muscular Strength in Women: A Meta-Analysis2021
A meta-analysis of 8 crossover studies in women found acute caffeine significantly improved muscular endurance (SMD 0.25) and muscular strength (SMD 0.18), with stronger effects on upper-body than lower-body tasks.
- Effect
- Benefit
- Population
- Women
RCTHigh Dose of Caffeine Mouth Rinse Increases Resistance Training Performance in Men2021
In 14 resistance-trained men, a high-dose (750 mg) caffeine mouth rinse significantly increased bench press repetitions to failure at 60% 1RM and reduced perceived exertion versus placebo; lower doses and 1-RM strength were unaffected.
- Effect
- Benefit
- Dose
- 250 mg
- Population
- Women
- Avg age
- 23±2
International Society of Sports Nutrition position stand: caffeine and exercise performance2021n=19
The 2021 ISSN position stand concludes caffeine at 3–6 mg/kg acutely enhances endurance, strength, sprinting, jumping, and cognitive performance in many but not all studies, with inter-individual response variation.
- Effect
- Benefit
- Dose
- 3–6 mg/kg
- Population
- Athletes
- Participants
- 19
RCTCaffeine Supplementation for 4 Days Does Not Induce Tolerance to the Ergogenic Effects Promoted by Acute Intake on Physiological, Metabolic, and Performance Parameters of Cyclists: A Randomized, Double-Blind, Crossover, Placebo-Controlled Study2020n=8
In 14 male cyclists, 4 days of caffeine 6 mg/kg/day did not induce tolerance; acute caffeine still improved 16 km time-trial time and power versus placebo on day 5.
- Effect
- Benefit
- Duration
- 4 days
- Dose
- 6 mg/day
- Population
- Men
- Participants
- 8
- Avg age
- 34.1±4.4
RCTCaffeine Supplementation or Carbohydrate Mouth Rinse Improves Performance2020n=29
In 29 active women, caffeine 6.5 mg/kg or carbohydrate mouth rinse both increased total resistance-training repetitions versus placebo, with no additional benefit from combining them.
- Effect
- Benefit
- Dose
- 6.5 mg/kg
- Population
- Women
- Participants
- 29
- Avg age
- ~24
RCTCaffeine Timing Improves Lower-Body Muscular Performance: A Randomized Trial2020n=18
In 29 resistance-trained adults, caffeine 6 mg/kg taken 1 hour before testing most consistently improved countermovement jump and isometric performance versus 30-minute or 2-hour timing.
- Effect
- Benefit
- Dose
- 100.3 mg/day
- Population
- Men
- Participants
- 18
- Avg age
- 25.1±5.7
MetaEffects of caffeine supplementation on muscle endurance, maximum strength, and perceived exertion in adults submitted to strength training: a systematic review and meta-analyses2020
A meta-analysis of 19 RCTs found caffeine significantly improved bench-press muscular endurance and maximal strength versus placebo, but effects on leg-press endurance and strength were inconsistent.
- Effect
- Benefit
- Population
- Healthy adults
Effects of CYP1A2 and ADORA2A Genotypes on the Ergogenic Response to Caffeine in Professional Handball Players2020n=15
In 31 professional handball players, 3 mg/kg caffeine improved countermovement jump, sprint velocity, and 9 m throw speed versus placebo; CYP1A2 and ADORA2A genotypes did not modulate most performance outcomes.
- Effect
- Benefit
- Dose
- 3 mg/day
- Population
- Athletes
- Participants
- 15
- Ages
- 18–40
RCTHabitual Caffeine Consumption Does Not Interfere With the Acute Caffeine Supplementation Effects on Strength Endurance and Jumping Performance in Trained Individuals2020
In 36 strength-trained adults stratified by habitual caffeine intake, acute 6 mg/kg caffeine improved countermovement jump and total repetitions regardless of low, moderate, or high daily caffeine consumption.
- Effect
- Benefit
- Dose
- 11 mg/day
- Population
- Adults
CrossoverThe effect of carbohydrate and caffeine mouth rinsing on kicking performance in competitive Taekwondo athletes during Ramadan2020
In 27 taekwondo athletes during Ramadan, caffeine mouth rinse improved successful kick percentage versus glucose or placebo in early fasting weeks, though Ramadan itself reduced baseline kick success.
- Effect
- Benefit
- Duration
- 4 weeks
- Population
- Athletes
MetaThe Effects of Caffeine Ingestion on Measures of Rowing Performance: A Systematic Review and Meta-Analysis2020
A meta-analysis of 7 rowing ergometer studies found acute caffeine improved 2000 m performance by about 4 seconds and increased mean power by 5.7 W versus placebo.
- Effect
- Benefit
- Population
- Adults
RCTCaffeine mouth rinse has no effects on anaerobic energy yield during a Wingate Test2019n=10
In 10 healthy men, a 300 mg caffeine mouth rinse before a Wingate test did not improve peak power, mean power, fatigue index, or anaerobic energy contribution versus placebo.
- Effect
- No Benefit
- Dose
- 300 mg
- Population
- Men
- Participants
- 10
- Avg age
- 24.8±3.7
RCTCaffeine Supplementation: Ergogenic in Both High and Low Caffeine Responders2019n=11
In 20 well-trained soccer players, caffeine 6 mg/kg improved time to fatigue and countermovement jump versus placebo in both high and low caffeine responders identified at rest.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Participants
- 11
MetaEstablishing a relationship between the effect of caffeine and duration of endurance athletic time trial events: A systematic review and meta-analysis2019
A meta-analysis of 40 endurance time-trial studies (56 comparisons) found caffeine's standardized effect size increased with event duration by 0.15 per 30 minutes, supporting greater benefits in longer events.
- Effect
- Benefit
- Population
- Athletes
MetaThe effects of caffeine ingestion on isokinetic muscular strength: A meta-analysis2019
A meta-analysis of 10 isokinetic strength studies found acute caffeine increased overall isokinetic strength by ~5.3%, with significant knee extensor benefits at 60°/s and 180°/s angular velocities.
- Effect
- Benefit
MetaWake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analyses2019
An umbrella review of 21 meta-analyses concluded caffeine is ergogenic for aerobic endurance, muscle strength, power, and jumping, with moderate-quality evidence for endurance and strength benefits.
- Effect
- Benefit
- Population
- Older adults
RCTCorrection to: The Effect of Acute Caffeine Ingestion on Endurance Performance: A Systematic Review and Meta-Analysis2018
A meta-analysis of 44 endurance time-trial studies found moderate caffeine doses (3–6 mg/kg) improved mean power by ~2.9% and completion time by ~2.3% versus placebo, though individual responses varied.
- Effect
- Benefit
- Dose
- 3–6 mg/kg
- Population
- Athletes
MetaEffects of acute ingestion of caffeine on team sports performance: a systematic review and meta-analysis2018
A meta-analysis of 34 team-sport studies found 3–6 mg/kg caffeine improved single and repeated jumps, sprint speed, agility time, match running distance, and sprint count versus placebo.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
RCTThe effect of CYP1A2 genotype on the ergogenic properties of caffeine during resistance exercise: a randomized, double-blind, placebo-controlled, crossover study2018n=16
In 30 resistance-trained men, acute caffeine 6 mg/kg increased total reps more in CYP1A2 AA homozygotes than C-allele carriers across bench press, leg press, row, and shoulder press exercises.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
- Participants
- 16
MetaThe effects of caffeine ingestion on isokinetic muscular strength: A meta-analysis2018
A meta-analysis of 10 isokinetic strength studies found acute caffeine increased overall isokinetic strength by ~5.3%, with significant knee extensor benefits at 60°/s and 180°/s angular velocities.
- Effect
- Benefit
MetaAcute effects of caffeine-containing energy drinks on physical performance: a systematic review and meta-analysis2017
A meta-analysis of energy-drink trials found caffeine-containing drinks improved muscle strength/endurance, endurance tests, jumping, and sport-specific actions versus placebo; taurine dose correlated with performance gains.
- Effect
- Benefit
RCTChronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine2017
In 18 low-habitual-caffeine adults over 28 days, chronic caffeine 1.5–3 mg/kg/day attenuated the acute ergogenic effect on endurance work versus baseline, suggesting tolerance development.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 1.5–3 mg/kg/day
- Population
- Adults
RCTEffects of Coffee and Caffeine Anhydrous Intake During Creatine Loading2016n=54
In 54 physically active adults, 5 days of creatine loading with or without caffeine or coffee similarly improved strength and sprint performance versus placebo; caffeine did not block creatine's effects.
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 300 mg/day caffeine
- Population
- Physically active adults
- Participants
- 54
- Avg age
- 20.1±2.1
RCTTime of Day and Training Status Both Impact the Efficacy of Caffeine for Short Duration Cycling Performance2016n=7
In 20 male cyclists, caffeine 6 mg/kg improved simulated 3 km time-trial performance in both morning and evening, with trained athletes benefiting more in the morning and untrained more in the evening.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
- Participants
- 7
- Avg age
- ~25
RCTCombined caffeine and carbohydrate ingestion: effects on nocturnal sleep and exercise performance in athletes2014
In male athlete triathletes/cyclists, late-afternoon caffeine 6 mg/kg with carbohydrate improved 5 km cycling time trial but reduced sleep efficiency, REM sleep, and total sleep time that night.
- Effect
- Benefit
- Dose
- 3 mg/kg
- Population
- Athletes
- Avg age
- 27.5±6.9
RCTAcute and chronic caffeine administration increases physical activity in sedentary adults2013
In sedentary adults undergoing repeated exercise sessions, caffeine increased spontaneous physical activity and reduced RPE, with greater activity increases in women; acute caffeine also extended exercise duration after chronic exposure.
- Effect
- Benefit
- Dose
- 3 mg/kg
- Population
- Female athletes
RCTCaffeine counteracts impairments in task-oriented psychomotor performance induced by chlorpheniramine: a double-blind placebo-controlled crossover study2013n=16
In 16 healthy men, 200 mg caffeine counteracted chlorpheniramine-induced reaction-time impairment and subjective sleepiness, restoring psychomotor performance to near placebo levels.
- Effect
- Benefit
- Dose
- 200 mg/day
- Population
- Athletes
- Participants
- 16
RCTCaffeine-containing energy drink improves sprint performance during an international rugby sevens competition2013n=27
In 16 Spanish national women's rugby sevens players, an energy drink with 3 mg/kg caffeine improved running pace and muscle power output during matches versus placebo.
- Effect
- Benefit
- Dose
- 3 mg/kg
- Population
- Women
- Participants
- 27
- Avg age
- 33±6.5
RCTThe effect of caffeine ingestion on skill maintenance and fatigue in epee fencers2013
In 11 competitive fencers, 3 mg/kg caffeine reduced overall perceived fatigue after fatiguing fencing exercise but did not significantly improve lunge accuracy or Stroop reaction times.
- Effect
- No Benefit
- Dose
- 3 mg/kg
- Population
- Athletes
- Avg age
- 33±6.5
RCTCaffeine and sprinting performance: dose responses and efficacy2012
In 17 well-trained men given caffeine doses from 2 to 10 mg/kg before 10-second sprints, caffeine did not significantly improve peak power, mean power, or time to peak power versus placebo.
- Effect
- No Benefit
- Dose
- 3–6 mg/kg
- Population
- Athletes
- Avg age
- 24±6
RCTThe influence of a CYP1A2 polymorphism on the ergogenic effects of caffeine2012n=19
In 35 trained male cyclists, 6 mg/kg caffeine reduced 40 km time-trial time by 4.9% in CYP1A2 AA homozygotes versus 1.8% in C-allele carriers, suggesting genotype-dependent ergogenic response.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
- Participants
- 19
- Avg age
- 25±7.3
RCTCaffeine ingestion, affect and perceived exertion during prolonged cycling2011
In 12 endurance-trained men cycling 90 min at 70% VO2max, caffeine 6 mg/kg maintained higher pleasure ratings and lower perceived exertion versus placebo, possibly contributing to ergogenic effects.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
Ergogenic Effects of Caffeine on Simulated Time-Trial Performance Are Independent of Fitness Level2011
A controlled trial titled to assess whether caffeine improves simulated time-trial performance independent of fitness level; no abstract text was available for further detail.
- Effect
- Benefit
No Effects of Caffeine on Muscle Hypertrophy-Style Resistance Exercise2011
A study titled to assess caffeine on hypertrophy-style resistance exercise reported no significant performance benefit from caffeine; no abstract text was available for further detail.
- Effect
- No Benefit
RCTThe effects of different doses of caffeine on endurance cycling time trial performance2011
In 16 well-trained male cyclists, caffeine 3 mg/kg improved time-trial performance by 4.2% versus 2.9% for 6 mg/kg and raised heart rate without changing RPE.
- Effect
- Benefit
- Dose
- 3 mg/day
- Population
- Athletes
- Avg age
- 32.6±8.3
Controlled trialCaffeinated chewing gum increases repeated sprint performance and augments increases in testosterone in competitive cyclists2010
In 9 competitive cyclists, caffeinated gum (240 mg) after repeated sprints reduced performance decline and increased post-exercise testosterone versus placebo, with lower cortisol in caffeine trials.
- Effect
- Benefit
- Dose
- 240 mg
- Population
- Athletes
- Avg age
- 24±7
RCTDose response of caffeine on 2000-m rowing performance2010
In 10 competitive male rowers, caffeine doses of 2–6 mg/kg did not significantly improve 2000 m ergometer time-trial performance despite large interindividual variation in plasma caffeine levels.
- Effect
- No Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
- Avg age
- 20.6±1.4
RCTEffect of ambient temperature on caffeine ergogenicity during endurance exercise2010
In 11 male cyclists, caffeine 3–6 mg/kg improved simulated 3 km time-trial performance similarly in cool (12°C) and warm (33°C) environments versus placebo.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
- Avg age
- 25±6
MetaEffect of caffeine ingestion on muscular strength and endurance: a meta-analysis2010n=27
A meta-analysis of 27 MVC strength studies found caffeine increased strength modestly overall (ES 0.19), with larger knee extensor effects (ES 0.37) and greater open-endpoint muscular endurance benefits (~18%).
- Effect
- Benefit
- Participants
- 27
RCTEffects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot & humid climate2010
In 9 heat-adapted Malaysian runners, 5 mg/kg caffeine before exercise significantly increased running time to exhaustion in hot, humid conditions without changing heart rate, VO2, or RPE patterns.
- Effect
- Benefit
- Dose
- 12.6 mg/day
- Population
- Athletes
- Avg age
- 25.4±6.9
RCTThe influence of caffeine and carbohydrate coingestion on simulated soccer performance2010n=14
In 15 men during a 90-min soccer simulation, adding caffeine to a carbohydrate-electrolyte drink improved sprint times and countermovement jump versus carbohydrate alone, offsetting fatigue-related declines.
- Effect
- Benefit
- Dose
- 1.8 g/kg
- Population
- Men
- Participants
- 14
RCTCaffeine enhances cognitive function and skill performance during simulated soccer activity2009n=12
In 12 healthy men completing two 90-min soccer simulations, 6 mg/kg caffeine reduced penalty time on a skill test and increased jump height versus placebo, suggesting better skill maintenance during simulated match play.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
- Participants
- 12
RCTCaffeine, cycling performance, and exogenous CHO oxidation: a dose-response study2009
In 9 trained male cyclists fed before exercise, caffeine 1.5 or 3 mg/kg did not significantly improve 7 km time-trial performance or exogenous carbohydrate oxidation versus placebo.
- Effect
- No Benefit
- Dose
- 3 mg/kg
- Population
- Athletes
RCTEffect of caffeine as an ergogenic aid during anaerobic exercise performance in caffeine naïve collegiate football players2009n=17
In 17 caffeine-naïve collegiate football players, 5 mg/kg caffeine before NFL combine-style tests did not significantly improve 40-yard dash, shuttle run, or bench press reps versus placebo.
- Effect
- No Benefit
- Dose
- 20 mg/day
- Population
- Athletes
- Participants
- 17
RCTThe effect of a carbohydrate-caffeine sports drink on simulated golf performance2009
In recreational golfers during a simulated round, a carbohydrate-caffeine sports drink improved 5 m and 2 m putting performance and alertness ratings versus flavor-matched placebo.
- Effect
- Benefit
- Dose
- 1.6 mg/kg
- Population
- Athletes
- Avg age
- 23±4
RCTCaffeine has a small effect on 5-km running performance of well-trained and recreational runners2008
In 30 runners (15 well-trained, 15 recreational), 5 mg/kg caffeine before 5 km time trials improved performance by ~1% in both groups versus placebo, a small but statistically significant ergogenic effect.
- Effect
- Benefit
- Dose
- 5 mg/kg
- Population
- Athletes
RCTThe effect of ephedra and caffeine on maximal strength and power in resistance-trained athletes2008
In resistance-trained men, caffeine 300 mg, ephedrine, or their combination increased alertness and mood but did not significantly improve strength, Wingate power, or muscular endurance versus placebo.
- Effect
- No Benefit
- Dose
- 300 mg
- Population
- Athletes
RCTEffects of caffeine on prolonged intermittent-sprint ability in team-sport athletes2006n=10
In 10 male team-sport athletes, 6 mg/kg caffeine before intermittent sprint exercise increased total sprint work by 8.5% in the first half and 7.6% in the second half versus placebo.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
- Participants
- 10
MetaEffects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis2005n=89
A meta-analysis of 21 studies found caffeine reduced rating of perceived exertion during exercise by 5.6% and explained about 29% of variance in performance improvement versus placebo.
- Effect
- Benefit
- Participants
- 89
MetaEffects of caffeine ingestion on exercise testing: a meta-analysis2004
A meta-analysis of 40 exercise-testing studies found caffeine improved test outcomes by 12.3% overall (ES 0.41), with the largest benefits in endurance time-to-exhaustion protocols.
- Effect
- Benefit
RCTLittle effect of caffeine ingestion on repeated sprints in team-sport athletes2001
In 16 team-sport athletes, 6 mg/kg caffeine before repeated 20 m sprints produced at most a negligible mean sprint improvement (~0.1%), suggesting little practical benefit for this task.
- Effect
- No Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
RCTComparison of caffeine and theophylline ingestion: exercise metabolism and endurance2000
In 8 men, caffeine 6 mg/kg and theophylline 4.5 mg/kg both extended cycling time to exhaustion versus placebo and increased blood glycerol, demonstrating ergogenic effects independent of muscle glycogen.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Athletes
CreatineView supplement →
Proven purchase·★★★★★
How we scored this▸
- Taking creatine monohydrate by mouth can slightly improve performance in sports including rowing, jumping, and soccer.
- Most studies in rowers show better times and less fatigue when using creatine for a short period.
- It may also help with jumping higher.
- Creatine might help more with strength and short bursts of activity than with endurance sports.
Browse 66 studies·3 meta-analyses
Clinical trialCaffeine, but Not Creatine, Improves Anaerobic Power Without Altering Anaerobic Capacity in Healthy Men During a Wingate Anaerobic Test2024n=12
In 24 healthy men, 8 days of 20 g/day creatine loading did not improve Wingate anaerobic power or capacity, while caffeine alone increased anaerobic power.
- Effect
- No Benefit
- Duration
- 8 days
- Dose
- 20 g/day
- Population
- Men
- Participants
- 12
MetaEffects of Creatine Monohydrate on Endurance Performance in a Trained Population: A Systematic Review and Meta-analysis2023
A meta-analysis of 13 trained-population trials found creatine monohydrate did not significantly improve endurance performance (pooled SMD −0.07; P=0.47).
- Effect
- No Benefit
- Population
- Athletes
RCTThe Effects of Creatine Monohydrate Loading on Exercise Recovery in Active Women throughout the Menstrual Cycle2023n=20
In 39 active women, 20 g/day creatine loading across the menstrual cycle improved fatigue index during repeated sprints in the luteal phase but did not change heart rate variability recovery.
- Effect
- Benefit
- Dose
- 20 g/day
- Population
- Women
- Participants
- 20
- Avg age
- 24.6±5.9
RCTThe Effects of Protein and Carbohydrate Supplementation, with and without Creatine, on Occupational Performance in Firefighters2023
In 30 male firefighters, 21–26 days of protein-carbohydrate supplementation with or without 5 g/day creatine improved rescue and forcible-entry task times only in the creatine group.
- Effect
- Benefit
- Duration
- 21–26 days
- Dose
- 5 g/day
- Population
- Heart failure patients
- Avg age
- 34.4±8.4
MetaShort-Term Creatine Supplementation and Repeated Sprint Ability-A Systematic Review and Meta-Analysis2022
A meta-analysis of 14 trials found short-term creatine loading (~20 g/day for 3–7 days) increased mean power during repeated sprints (δ=0.61) and body mass by 0.79 kg, without effects on peak power or fatigue.
- Effect
- Benefit
- Duration
- 3–7 days
- Dose
- 20 g/day
- Ages
- 18–60
MetaCreatine supplementation and VO2max: a systematic review and meta-analysis2021n=216
A meta-analysis of 19 VO2max trials (424 participants) found creatine supplementation was associated with slightly lower VO2max gains than placebo (ES −0.32 to −0.20).
- Effect
- No Benefit
- Population
- Healthy adults
- Participants
- 216
- Ages
- 50+
RCTMorning versus Evening Intake of Creatine in Elite Female Handball Players2021
In 14 elite female handball players, 12 weeks of creatine taken morning or evening similarly improved body composition and performance, suggesting timing did not matter.
- Effect
- No Benefit
- Population
- Female athletes
- Ages
- 18–35
RCTShort-term co-ingestion of creatine and sodium bicarbonate improves anaerobic performance in trained taekwondo athletes2021n=8
In 40 trained taekwondo athletes, 5 days of creatine plus sodium bicarbonate raised mean power more than creatine or bicarbonate alone during intermittent kick tests.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 0.5 g/kg
- Population
- Athletes
- Participants
- 8
- Avg age
- ~22
ISSN exercise & sports nutrition review update: research & recommendations2018
A 2018 ISSN review summarizes regulation, evaluation, and evidence for sports nutrition supplements, with emphasis on dietary strategies and ergogenic aids for muscle hypertrophy and performance enhancement.
- Population
- Athletes
RCTCreatine Monohydrate Supplementation Does Not Augment Fitness, Performance, or Body Composition Adaptations in Response to Four Weeks of High-Intensity Interval Training in Young Females2017n=9
In 17 recreationally active women, 4 weeks of HIIT plus creatine (0.3 then 0.1 g/kg/day) improved VO2peak and time-trial performance similarly to HIIT plus placebo.
- Effect
- No Benefit
- Duration
- 23 days
- Dose
- 0.1 g·kg⁻¹/day
- Population
- Women
- Participants
- 9
- Avg age
- 23±4
RCTAcute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance2016n=48
In 48 participants, 28 days of creatine nitrate at 1.5–3 g/day was well tolerated and matched 3 g creatine monohydrate on bench press volume, with the highest dose showing the largest gains.
- Effect
- Benefit
- Dose
- 1.5 g/day
- Participants
- 48
- Avg age
- 22±5
RCTEffects of plyometric training and creatine supplementation on maximal-intensity exercise and endurance in female soccer players2016n=10
In female soccer players doing 6 weeks of plyometric training, creatine plus training improved repeated sprint and endurance performance more than plyometrics with placebo.
- Effect
- Benefit
- Population
- Female athletes
- Participants
- 10
- Avg age
- ~23
RCTEffect of creatine supplementation on jumping performance in elite volleyball players2011n=420
In 8 elite volleyball players, creatine loading improved repeated block-jump height in sets 3–6 versus placebo, with no clear benefit on single-jump or first-set performance.
- Effect
- Benefit
- Dose
- 20 g/day
- Population
- Athletes
- Participants
- 420
RCTCreatine supplementation improves the anaerobic performance of elite junior fin swimmers2009
In 16 junior fin swimmers, 5 days of 20 g/day creatine improved 100 m swim times and average power during repeated sprints versus placebo.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 20 g/day
- Population
- Children
- Avg age
- 15.9±1.6
RCTComparison of creatine monohydrate and carbohydrate supplementation on repeated jump height performance2008n=15
In 60 active men, carbohydrate at 250 kcal/day maintained repeated jump height over final sprints as effectively as creatine, without the weight gain seen with creatine.
- Effect
- Benefit
- Duration
- 5 days
- Population
- Athletes
- Participants
- 15
- Ages
- 50+
RCTThe effects of creatine supplementation on selected factors of tennis specific training2006
In 36 competitive male tennis players, 6 days of creatine loading did not improve serving velocity, stroke velocity, sprint power, or upper/lower-body strength versus placebo.
- Effect
- No Benefit
- Population
- Heart failure patients
- Avg age
- ~23
RCTEffects of acute creatine loading with or without carbohydrate on repeated bouts of maximal swimming in high-performance swimmers2005
In high-performance swimmers, 4 days of 25 g/day creatine with or without carbohydrate improved swim performance similarly, with gains persisting up to 4 weeks.
- Effect
- Benefit
- Duration
- 4 days
- Dose
- 25 g/day
- Avg age
- 17.8±1.8
RCTThe effects of acute creatine supplementation on multiple sprint cycling and running performance in rugby players2005
In rugby players, 5 days of 20 g/day creatine loading showed only small, mostly non-significant trends toward better repeated sprint cycling and running performance.
- Effect
- No Benefit
- Dose
- 20 g/day
RCTCreatine supplementation and performance in 6 consecutive 60 meter sprints2004n=19
In 19 men, 5 days of 20 g/day creatine did not improve performance across 6 consecutive 60 m sprints, though plasma creatinine rose and post-sprint ventilation changed.
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 20 g/day
- Population
- Men
- Participants
- 19
RCTCreatine supplementation in young soccer players2004
In young male soccer players, 7 days of creatine (3×10 g/day) improved dribble test time versus placebo, with no significant sprint-power or endurance differences.
- Effect
- Benefit
- Duration
- 7 days
- Dose
- 10 g/day
- Population
- Athletes
- Avg age
- ~17
RCTCreatine supplementation: effects on urinary excretion and anaerobic performance2003
In sprint-trained men, 4 days of creatine at 10–35 g/day raised urinary creatine excretion and peak/mean Wingate power versus placebo.
- Effect
- Benefit
- Duration
- 4 days
- Dose
- 10–35 g/day
- Population
- Heart failure patients
RCTEffect of creatine supplementation on aerobic performance and anaerobic capacity in elite rowers in the course of endurance training2003n=8
In 16 elite rowers, 5 days of 20 g/day creatine during training raised lactate threshold and extended anaerobic rowing time versus placebo, without changing maximal power.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 20 g/day
- Population
- Athletes
- Participants
- 8
Controlled trialEffect of creatine supplementation on intermittent sprint running performance in highly trained athletes2003
In trained sprinters, 7 days of high-dose creatine (0.35 g/kg/day) did not change single or repeated 40 m sprint performance or recovery between sprints.
- Effect
- No Benefit
- Dose
- 0.35 g/kg
- Population
- Athletes
RCTSwim performance following creatine supplementation in Division III athletes2003
In Division III swimmers, creatine loading followed by 2.25 g/day maintenance improved 50- and 100-yd sprint times versus placebo.
- Effect
- Benefit
- Duration
- 9 days
- Dose
- 2.25 g/day
- Population
- Athletes
RCTThe effects of 8 weeks of creatine monohydrate and glutamine supplementation on body composition and performance measures2003n=10
In 29 track athletes over 8 weeks, creatine with or without glutamine increased lean body mass and initial power output during cycle ergometry more than placebo.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 0.3 g/day
- Population
- Athletes
- Participants
- 10
RCTEffect of recovery interval on multiple-bout sprint cycling performance after acute creatine supplementation2002n=30
In 30 men, 7 days of creatine loading improved mean and peak power during repeated 15-second sprints most when recovery intervals were 1 or 3 minutes rather than 6 minutes.
- Effect
- Benefit
- Duration
- 7 days
- Dose
- 0.3 g·kg⁻¹/day
- Population
- Adults
- Participants
- 30
RCTEffects of creatine supplementation on muscle power, endurance, and sprint performance2002n=10
In 19 handball players, 5 days of 20 g/day creatine increased repeated high-power bench-press and squat work, 1RM half-squat, and early sprint speed, but not upper-body 1RM or endurance running.
- Effect
- Benefit
- Dose
- 20 g/day
- Population
- Heart failure patients
- Participants
- 10
RCTCreatine loading does not impact on stroke performance in tennis2001
In elite tennis players, 5 days of creatine loading (4×5 g/day) did not improve stroke accuracy, ball velocity, service performance, or shuttle-run time versus placebo.
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 5 g/day
RCTEffect of creatine loading on long-term sprint exercise performance and metabolism2001n=7
In 14 men, 5 days of 20 g/day creatine increased total work by 6% and peak power during 80 minutes of repeated sprints versus placebo.
- Effect
- Benefit
- Dose
- 20 g/day
- Population
- Men
- Participants
- 7
RCTEffect of creatine supplementation on metabolism and performance in humans during intermittent sprint cycling2001
In 16 triathletes, 5 days of 100 g/day creatine raised muscle total creatine but did not significantly improve peak or mean power across four 20-second sprints.
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 100 g/day
- Ages
- 18–65
RCTEffects of creatine monohydrate supplementation during combined strength and high intensity rowing training on performance2001n=55
In 22 rowers trained for 6 weeks, creatine loading and maintenance did not improve 2000 m rowing time, interval power, or strength beyond placebo plus identical training.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 0.3 g/kg
- Participants
- 55
RCTEffects of oral creatine supplementation on high intensity, intermittent exercise performance in competitive squash players2001
In competitive squash players, 5 days of creatine (0.075 g/kg four times daily) improved on-court sprint times by 3.2% versus placebo, especially from set 2 onward.
- Effect
- Benefit
- Dose
- 0.075 g·kg⁻¹/day
Controlled trialEffects of oral creatine supplementation on maximal pedalling performance in older adults2001n=14
In sedentary elderly and young men, 5 days of creatine (3×5 g/day) improved maximal pedalling power during 10-second sprints; trained elderly cyclists showed no benefit.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 15 g/day
- Population
- Men
- Participants
- 14
- Ages
- 18–65
RCTCreatine enhances oxygen uptake and performance during alternating intensity exercise2000n=14
In 14 men, 5 days of 20 g/day creatine increased oxygen uptake during high-intensity alternating cycling and extended time to exhaustion from 29.9 to 36.5 minutes.
- Effect
- Benefit
- Dose
- 20 g/day
- Population
- Heart failure patients
- Participants
- 14
RCTCreatine monohydrate supplementation enhances high-intensity exercise performance in males and females2000n=12
In 24 adults, 4 days of 20 g/day creatine increased peak and mean anaerobic cycling power by about 4% and dorsiflexion MVC torque by 6.6% in both men and women.
- Effect
- Benefit
- Duration
- 4 days
- Dose
- 20 g/day
- Population
- Adults
- Participants
- 12
RCTCreatine supplementation and sprint performance in soccer players2000
In 17 soccer players, 6 days of creatine loading (5 g four times daily) improved 5 m and 15 m sprint times and helped preserve jump ability after an intermittent endurance test.
- Effect
- Benefit
- Dose
- 20 g/day
- Population
- Athletes
- Ages
- 18–65
Controlled trialEffect of creatine feeding on maximal exercise performance in vegetarians2000
In vegetarians and meat-eaters, 1 week of creatine supplementation similarly increased body mass and mean Wingate power by about 5%; peak power rose significantly only in meat-eaters.
- Effect
- Benefit
- Duration
- 1 week
Controlled trialNo acute effects of short-term creatine supplementation on muscle properties and sprint performance2000
In 23 rowers, 6 days of 20 g/day creatine increased body mass but did not improve muscle activation, fatigue, recovery, or 30-second sprint cycling performance.
- Effect
- No Benefit
- Duration
- 6 days
- Dose
- 20 g/day
RCTCreatine supplementation and swimming performance1999
In university swimmers, 2 weeks of creatine improved mean velocity during 6×50 m intervals in men but not women, with no effect on 10×25 yd intervals in either sex.
- Effect
- Benefit
- Duration
- 2 weeks
- Population
- Adults
RCTCreatine supplementation increases muscle total creatine but not maximal intermittent exercise performance1999n=14
In 14 volunteers, 5 days of creatine raised muscle total creatine but did not improve peak power or work during five 10-second sprints versus placebo.
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 20 g/day
- Participants
- 14
Controlled trialCreatine supplementation--part I: performance, clinical chemistry, and muscle volume1999
In 10 trained men, 5 days of 20 g/day creatine improved late-sprint power during repeated 6-second efforts by 7% and lowered blood lactate, without MRI-detectable lower-limb muscle mass gain.
- Effect
- Benefit
- Dose
- 20 g/day
- Population
- Heart failure patients
RCTEffects of in-season (5 weeks) creatine and pyruvate supplementation on anaerobic performance and body composition in American football players1999n=11
In 42 football players over about 50 weeks, creatine alone or with pyruvate increased lean mass, 1RM strength, and static vertical jump power more than pyruvate or placebo.
- Effect
- Benefit
- Duration
- 50 weeks
- Participants
- 11
RCTOral creatine supplementation improves multiple sprint performance in elite ice-hockey players1999n=8
In 16 elite ice-hockey players, creatine loading plus 5 g/day for 10 weeks increased cycle sprint mean power and improved 47 m on-ice sprint times.
- Effect
- Benefit
- Duration
- 10 weeks
- Dose
- 5 g/day
- Participants
- 8
Controlled trialThe effect of longer-term creatine supplementation on elite swimming performance after an acute creatine loading1999n=22
In 22 elite swimmers, 4 days of 25 g/day creatine loading improved interval swim times, but 2 months of 5 g/day maintenance did not beat placebo.
- Effect
- Benefit
- Duration
- 2 months
- Dose
- 25 g/day
- Participants
- 22
RCTCreatine and caffeine in anaerobic and aerobic exercise: effects on physical performance and pharmacokinetic considerations1998
In 7 trained athletes, 3 days of creatine (3×100 mg/kg/day) with or without caffeine did not improve anaerobic or aerobic cycling performance versus placebo.
- Effect
- No Benefit
- Duration
- 3 days
- Dose
- 300 mg/kg/day
- Population
- Athletes
RCTCreatine supplementation delays onset of fatigue during repeated bouts of sprint running1998
In handball players, 5 days of 15 g/day creatine improved performance on the last three of eight 40 m sprints versus placebo; low-dose maintenance effects were inconclusive.
- Effect
- Benefit
- Dose
- 100 mg/day
- Population
- Heart failure patients
RCTEffect of creatine loading on endurance capacity and sprint power in cyclists1998n=12
In 12 cyclists, creatine loading improved peak and mean sprint power after a 2.5-hour ride by 8–9%, but taking creatine during exercise abolished the endurance benefit.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 25 g/day
- Participants
- 12
Controlled trialEffect of creatine supplementation on sprint exercise performance and muscle metabolism1998
In 8 untrained men, 5 days of 30 g/day creatine plus dextrose raised muscle total creatine by 9.5% but did not improve 20-second sprint performance or anaerobic metabolite changes.
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 30 g/day
- Population
- Heart failure patients
RCTThe effects of creatine supplementation on high-intensity exercise performance in elite performers1998
In elite kayakers, 5 days of creatine (20 g/day) increased work completed during 90–300 s maximal efforts by 8–11% versus placebo, with no body mass change.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 20 g/day
- Population
- Athletes
- Avg age
- ~21
Controlled trialCreatine supplementation does not improve physical performance in a 150 m race1997
In 12 national-class sprinters, 25 g/day creatine for 3 days before a 150 m race raised plasma creatinine but did not improve race performance.
- Effect
- No Benefit
- Duration
- 3 days
- Dose
- 25 g/day
RCTCreatine supplementation enhances intermittent work performance1997n=18
In 18 participants, 5 days of 18.75 g/day creatine extended time to exhaustion during high-intensity intermittent cycling by 10–164% depending on work-rest protocol versus placebo.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 18.75 g/day
- Participants
- 18
RCTEffect of oral creatine supplementation on jumping and running performance1997
In sprint- and jump-trained athletes, 20 g/day creatine for 5 days improved 45-second continuous jumping by 7–12% in early intervals and prolonged high-intensity running time to exhaustion by 13%.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 20 g/day
- Population
- Athletes
RCTEffect of oral creatine supplementation on muscle [PCr] and short-term maximum power output1997
In 9 men, 3 days of 20 g/day creatine raised muscle total creatine/ATP ratio but did not improve Wingate peak power, mean power, or fatigue versus placebo.
- Effect
- No Benefit
- Dose
- 20 g/day
- Population
- Heart failure patients
RCTEffects of creatine supplementation on repetitive sprint performance and body composition in competitive swimmers1997
In junior swimmers supplemented for 9 days, 21 g/day creatine improved first-heat 100 m freestyle time and overall sprint performance versus placebo.
- Effect
- Benefit
- Duration
- 9 days
- Dose
- 20 g/day
- Population
- Adults
The effect of oral creatine supplementation on maximal exercise performance in competitive rowers1997
A creatine supplementation study in competitive rowers examined effects on maximal exercise performance, but no abstract was available to report specific outcomes.
- Effect
- Benefit
RCTThe influence of recovery duration on high-intensity exercise performance after oral creatine supplementation1997n=80
In 80 men, 5 days of 20 g/day creatine did not improve ability to maintain peak power during a second sprint after 30–120 s recovery intervals.
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 20 g/day
- Population
- Men
- Participants
- 80
RCTCreatine supplementation does not improve sprint performance in competitive swimmers1996
In 20 highly trained swimmers, 5 days of 5 g creatine four times daily did not improve 25–100 m sprint times but reduced post-exercise blood ammonia at some distances.
- Effect
- No Benefit
- Dose
- 5 g/day
- Population
- Heart failure patients
RCTEffect of oral creatine supplementation on single-effort sprint performance in elite swimmers1996n=16
In 32 elite swimmers, 5 days of creatine (4×5 g/day) did not improve 25–100 m sprint times or 10-second leg ergometer power versus placebo.
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 5 g/day
- Participants
- 16
- Ages
- 17–25
Controlled trialEffects of oral creatine supplementation on multiple sprint cycle performance1996n=9
In 17 recreationally active men, 4 days of creatine at 4×70 mg/kg/day did not improve repeated 10-second cycle sprint performance, lactate, pH, or VO2peak.
- Effect
- No Benefit
- Duration
- 4 days
- Dose
- 10 g/day
- Population
- Heart failure patients
- Participants
- 9
Controlled trialThe effect of oral creatine monohydhydrate supplementation on running velocity1996n=18
In 18 subjects, 7 days of creatine-glucose loading did not improve segmental velocity during three 60 m sprints versus placebo.
- Effect
- No Benefit
- Duration
- 7 days
- Participants
- 18
Controlled trialThe effect of oral creatine supplementation on the 1000-m performance of competitive rowers1996n=19
In 19 competitive rowers, 5 days of creatine at 0.25 g/kg/day improved 1000 m ergometer time by 2.3 seconds (~1%) in 16 of 19 athletes versus no change on placebo.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 0.25 g/day
- Population
- Athletes
- Participants
- 19
Controlled trialEffect of creatine supplementation on intramuscular TCr, metabolism and performance during intermittent, supramaximal exercise in humans1995
In 6 men, 5 days of creatine raised muscle total creatine and phosphocreatine but did not extend time to fatigue during supramaximal intermittent cycling.
- Effect
- No Benefit
- Duration
- 5 days
- Population
- Heart failure patients
RCTEffect of oral creatine supplementation on power output and fatigue during bicycle ergometry1995n=6
In 12 untrained men, 5 days of creatine supplementation did not improve 15-second maximal cycling peak power, total work, or fatigue index versus placebo.
- Effect
- No Benefit
- Duration
- 5 days
- Population
- Heart failure patients
- Participants
- 6
- Avg age
- ~24
RCTEffects of oral creatine loading on single and repeated maximal short sprints1995n=11
In repeated sprint studies, creatine loading increased total work during six 6-second sprints and peak power in sprint 1 versus placebo, while a single 10-second sprint test showed no between-group difference.
- Effect
- Benefit
- Dose
- 20 g/day
- Participants
- 11
Clinical trialSkeletal muscle metabolism during short duration high-intensity exercise: influence of creatine supplementation1995
In 7 men, 6 days of 20 g/day creatine raised resting muscle creatine by about 18% but did not improve power during repeated 6-second cycle sprints versus baseline.
- Effect
- Benefit
- Dose
- 20 g/day
- Population
- Men
RCTThe influence of dietary creatine supplementation on performance during repeated bouts of maximal isokinetic cycling in man1994
In men performing three 30-second maximal isokinetic cycling bouts, 5 days of 20 g/day creatine improved peak and mean power in bouts 1 and 2 but not bout 3, with lower peak ammonia.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 20 g/day
Whey ProteinView supplement →
Consider purchase·★★★★★
How we scored this▸
- Taking whey protein regularly with exercise can help increase muscle strength, size, and lean body mass in healthy young adults.
- Most research shows benefits when people take about 30 to 33 grams daily or 1.2 to 1.5 grams per kilogram of body weight while doing strength training for several weeks.
- Taking higher amounts (46 to 77 grams daily) may improve strength more.
- Whey protein may also slightly improve running speed if taken twice daily.
- However, taking small amounts occasionally, or taking whey protein without exercise, usually does not improve muscles or strength.
- Whey protein works about as well as other common protein sources like soy or beef.
Browse 18 studies·1 meta-analysis
RCTNo Significant Differences in Muscle Growth and Strength Development When Consuming Soy and Whey Protein Supplements Matched for Leucine Following a 12 Week Resistance Training Program in Men and Women: A Randomized Trial2020n=42
In 61 untrained adults, 12 weeks of resistance training with soy protein (26 g, 2 g leucine) vs whey (19 g, 2 g leucine) produced comparable gains in lean mass and strength.
- Effect
- No Benefit
- Duration
- 12 weeks
- Dose
- 26 g/day soy protein
- Population
- Adults
- Participants
- 42
- Ages
- 18–35
MetaEffect of whey protein supplementation during resistance training sessions on body mass and muscular strength: a meta-analysis2019n=837
In a meta-analysis of 837 participants, wP supplementation during RT sessions was found to improve lean mass, fat mass and muscular strength in healthy and younger individuals.
- Effect
- Benefit
- Duration
- 13.1 weeks
- Participants
- 837
- Ages
- 18+
RCTEffect of Protein Supplementation During Diet-Induced Weight Loss on Muscle Mass and Strength: A Randomized Controlled Study2018
In an RCT in postmenopausal women, 0.8 g/kg, the dietary interventions did not affect muscle strength.
- Effect
- No Benefit
- Dose
- 0.8 g/kg
- Population
- Postmenopausal women
- Ages
- 50–65
RCTEffect of Whey Protein Supplementation on Physical Performance and Body Composition in Army Initial Entry Training Soldiers2018n=35
In an RCT of 35 participants, 77 g/day, for 8 weeks, post-testing push-up performance averaged 7 repetitions higher in the WP compared to the CHO group (F = 10.1, p p = 0.04), but no significant change in run performance (F = 3.50, p = 0.065) or fat-free mass (F = 0.70, p = 0.41).
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 77 g/day
- Population
- Military recruits
- Participants
- 35
- Avg age
- 19±1
RCTThe Effects of Beef, Chicken, or Whey Protein After Workout on Body Composition and Muscle Performance2018n=41
In an RCT of 41 participants, for 8 weeks, whey protein concentrate (52.48 ± 11.15 to 54.96 ± 11.85 kg), Beef (51.68 ± 7.61 to 54.65 ± 8.67 kg), and Chx (52.97 ± 12.12 to 54.89 ± 13.43 kg) each led to a significant increase in lean body mass compared with baseline (p < 0.0001), whereas the control condition did not (53.14 ± 11.35 to...
- Effect
- Benefit
- Duration
- 8 weeks
- Population
- Adults
- Participants
- 41
- Ages
- 17–26
RCTResistance Training-Induced Elevations in Muscular Strength in Trained Men Are Maintained After 2 Weeks of Detraining and Not Differentially Affected by Whey Protein Supplementation2017n=20
In an RCT of 20 participants, for 2 weeks, therefore, a short-term period of DT can potentially retain lower-body strength in young resistance-trained men irrespective of supplementing with 25 g of whey protein postexercise.
- Effect
- No Benefit
- Duration
- 2 weeks
- Dose
- 25 g/day
- Population
- Men
- Participants
- 20
- Avg age
- ~21
RCTEight weeks of pre- and postexercise whey protein supplementation increases lean body mass and improves performance in Division III collegiate female basketball players2016n=8
In an RCT of 8 participants, 24 g whey protein/day, for 8 weeks, moreover, the WP group improved agility from T1 to T2 (p = 0.001) whereas the MD group did not (p = 0.38).
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 24 g whey protein/day
- Population
- Female athletes
- Participants
- 8
- Avg age
- 20±2
RCTEffect of whey protein hydrolysate on performance and recovery of top-class orienteering runners2015
In an RCT in athletes, 0.3 g/kg, in conclusion, ingestion of whey protein hydrolysate before and after each exercise session improves performance and reduces markers of muscle damage during a strenuous 1-week training camp.
- Effect
- Benefit
- Dose
- 0.3 g/kg
- Population
- Athletes
RCTWhey protein supplementation during resistance training augments lean body mass2013n=22
In an RCT of 22 participants, 1.4 g/kg, for 9 months, these results highlight the importance of protein quality as an important determinant of lean body mass responses to resistance training.
- Effect
- Benefit
- Duration
- 9 months
- Dose
- 1.4 g/kg
- Population
- Adults
- Participants
- 22
RCTThe effects of supplementation with creatine and protein on muscle strength following a traditional resistance training program in middle-aged and older men2010n=11
In an RCT of 11 participants, 5 g creatine/day + 35 g whey protein/day, for 14 weeks, resistance training in middle-aged and older men significantly increased muscular strength and added muscle mass with no additional benefits from creatine and/or protein supplementation.
- Effect
- No Benefit
- Duration
- 14 weeks
- Dose
- 5 g creatine/day + 35 g whey protein/day
- Population
- Older men
- Participants
- 11
- Ages
- 48–72
RCTAcute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression2009n=11
In an RCT of 11 participants, 15 g whey protein before and after exercise, for 21 weeks, in conclusion, protein intake close to resistance exercise workout may alter mRNA expression in a manner advantageous for muscle hypertrophy.
- Effect
- Benefit
- Duration
- 21 weeks
- Dose
- 15 g whey protein before and after exercise
- Population
- Men
- Participants
- 11
RCTResistance training with soy vs whey protein supplements in hyperlipidemic males2009n=10
In 28 overweight hyperlipidemic men, 12 weeks of resistance training with soy or whey protein (1.2 g/kg) similarly improved strength and reduced body fat and waist-to-hip ratio.
- Effect
- No Benefit
- Duration
- 12 weeks
- Dose
- 1.2 g/kg
- Population
- Men
- Participants
- 10
- Ages
- 21–50
RCTThe effects of creatine and whey protein supplementation on body composition in men aged 48 to 72 years during resistance training2008n=11
In an RCT of 11 participants, for 14 weeks, there were no significant changes for total calorie, carbohydrate, fat or protein intake for any of the groups from prestudy to post-study testing.
- Effect
- No Benefit
- Duration
- 14 weeks
- Dose
- 35 g/day
- Population
- Older men
- Participants
- 11
- Ages
- 48–72
RCTEffects of whey isolate, creatine, and resistance training on muscle hypertrophy2007
In an RCT in men, 1.5 g/kg/day creatine + whey, these differences in skeletal muscle morphology may have important implications for various populations and, therefore, warrant further investigation.
- Effect
- Benefit
- Dose
- 1.5 g/kg/day
- Population
- Men
RCTEffect of whey and soy protein supplementation combined with resistance training in young adults2006n=9
In 27 untrained adults, 6 weeks of resistance training with soy or whey protein (1.2 g/kg) both increased lean mass and strength vs placebo, with no difference between protein sources.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 1.2 g/kg
- Population
- Healthy adults
- Participants
- 9
- Ages
- 18–35
RCTThe effect of whey isolate and resistance training on strength, body composition, and plasma glutamine2006
In 13 male bodybuilders over 10 weeks, whey isolate produced greater lean-mass gain (5.0 vs 0.8 kg) than casein with identical resistance training.
- Effect
- Benefit
- Duration
- 10 weeks
- Dose
- 1.5 g/kg
- Population
- Pregnant women
RCTSoy versus whey protein bars: effects on exercise training impact on lean body mass and antioxidant status2004n=9
In an RCT of 9 participants, 33 g/day, for 9 weeks, both the soy and whey treatment groups showed a gain in lean body mass, but the training-only group did not.
- Effect
- Benefit
- Duration
- 9 weeks
- Dose
- 33 g/day
- Population
- Healthy adults
- Participants
- 9
- Ages
- 19–25
RCTThe effect of whey protein supplementation with and without creatine monohydrate combined with resistance training on lean tissue mass and muscle strength2001
In an RCT in healthy adults, 1.2 g/kg, for 6 weeks, however, not all strength measures were improved with supplementation, since subjects who supplemented with creatine and/or whey protein had similar increases in squat strength and knee flexion peak torque compared to subjects who received placebo.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 1.2 g/kg
- Population
- Healthy adults
AshwagandhaView supplement →
Consider purchase·★★★★★
How we scored this▸
- It is not clear if ashwagandha helps improve athletic performance.
- Some studies suggest that taking ashwagandha in doses from about 120 mg to 1250 mg daily for up to 6 months may improve endurance, muscle strength, speed, and recovery in people who exercise and those who don’t.
- One study showed that taking a specific ashwagandha extract (300 mg twice a day) with resistance training for 8 weeks improved endurance but did not increase muscle strength compared to no treatment.
- More research is needed to know if ashwagandha really helps athletes perform better.
Browse 7 studies·2 meta-analyses
RCTEffects of Ashwagandha (Withania somnifera) standardized root extract on physical endurance and VO2max in healthy adults performing resistance training: An eight-week, prospective, randomized, double-blind, placebo-controlled study2024n=40
In 40 young adults doing resistance training for 8 weeks, ashwagandha 600 mg/day increased muscle strength, size, and recovery versus placebo.
- Effect
- Benefit
- Dose
- 300 mg 2×/day
- Population
- Athletes
- Participants
- 40
- Ages
- 18–45
MetaEffects of Ashwagandha (Withania somnifera) on Physical Performance: Systematic Review and Bayesian Meta-Analysis2021
A systematic review and Bayesian meta-analysis concluded ashwagandha supplementation may benefit multiple physical performance outcomes, though study heterogeneity limits certainty.
- Effect
- Benefit
- Population
- Adults
MetaEffects of Ashwagandha (Withania somnifera) on VO2max: A Systematic Review and Meta-Analysis2020n=142
A meta-analysis found ashwagandha supplementation may increase VO2max in athletes and non-athletes, but evidence is limited and heterogeneous.
- Effect
- Benefit
- Duration
- 2–12 weeks
- Dose
- 1000 mg/day
- Population
- Athletes
- Participants
- 142
RCTEffects of an Aqueous Extract of Withania somnifera on Strength Training Adaptations and Recovery: The STAR Trial2018n=19
A 12-wk manufacturer-funded study including 38 recreationally active men found ashwagandha (500 mg/day Sensoril) led to significant improvements in 1-repetition max squat strength (Ash: +19.1 ± 13.0 kg vs. Placebo +10.0 ± 6.2 kg, P = 0.009) and bench press (Ash: +12.8 ± 8.2 kg vs. Placebo: +8.0 ± 6.0 kg, P = 0.048). Ashwagandha supplementation improved average squat power, peak bench press power, 7.5 km cycling time trial performance, and perceived recovery scores. Participants taking ashwagandha experienced favourable changes in abdominal fat to hip fat ratio (Ash: +0.0 ± 0.14 vs. Placebo: +0.09 ± 0.1, P = 0.03) compared to placebo.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 500 mg/day
- Population
- Men
- Participants
- 19
- Avg age
- ~27
RCTExamining the effect of Withania somnifera supplementation on muscle strength and recovery: a randomized controlled trial2015n=29
In 57 young men resistance training for 8 weeks, ashwagandha 300 mg twice daily increased muscle strength and upper-limb muscle size versus placebo.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 300 mg 2×/day
- Population
- Men
- Participants
- 29
- Ages
- 18–50
Effects of eight-week supplementation of Ashwagandha on cardiorespiratory endurance in elite Indian cyclists2012n=20
In 40 healthy cyclists over 8 weeks, ashwagandha 500 mg twice daily improved VO2max, METS, and time to exhaustion on treadmill testing versus placebo.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 1000 mg/day
- Population
- Athletes
- Participants
- 20
- Ages
- 18–27
Effects of Withania somnifera (Ashwagandha) and Terminalia arjuna (Arjuna) on physical performance and cardiorespiratory endurance in healthy young adults2010n=10
An 8-week study assigned 40 healthy young participants either 500 mg/day ashwagandha (n = 10), 500 mg/day Terminalia arjuna bark extract (n = 10), ashwagandha + Terminalia arjuna (n = 10), or placebo. The ashwagandha-only group experienced significant improvements in max sprint velocity, vertical jump power and VO2 max. Terminalia arjuna supplementation significantly improved VO2 max and reduced resting systolic blood pressure compared to placebo. The combination group experienced significant increases in max sprint velocity, average absolute power, average relative power, VO2 max and reduced systolic blood pressure (all parameters except balance and diastolic blood pressure).
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 500 mg/day
- Population
- Young adults
- Participants
- 10
- Avg age
- ~21
Beta-AlanineView supplement →
Consider purchase·★★★★★
How we scored this▸
- Taking beta-alanine supplements can help improve endurance during high-intensity exercise lasting about 1 to 4 minutes, such as sprinting or rowing.
- Studies show that beta-alanine improves exercise capacity by roughly 3% compared to placebo.
- It does not appear to help much with very short bursts of activity lasting less than a minute.
- To see benefits, it’s usually necessary to take beta-alanine daily for at least 3 to 6 weeks, with typical doses from 2 to 6 grams per day.
- Most research has been done in men, with less information available for women.
Browse 56 studies·7 meta-analyses
MetaAdvantages of different dietary supplements for elite combat sports athletes: a systematic review and Bayesian network meta-analysis2025
A network meta-analysis of 67 combat-sports RCTs found beta-alanine was among supplements associated with higher blood lactate, alongside caffeine and sodium bicarbonate.
- Effect
- Benefit
- Population
- Athletes
RCTBeta-alanine supplementation improves time to exhaustion, but not aerobic capacity, in competitive middle- and long-distance runners2025n=14
A 4-week RCT of 27 adolescent runners found beta-alanine increased time to exhaustion 6.5% versus 1.4% on placebo without raising VO2peak.
- Effect
- Benefit
- Duration
- 4 weeks
- Population
- Athletes
- Participants
- 14
- Avg age
- ~17
MetaEffects of Different Dietary Supplements on Swimming Performance: A Systematic Review and Network Meta-Analysis2024
A swimming network meta-analysis found beta-alanine ranked best for reducing blood lactate, while L-arginine was top for 100 m time and creatine plus bicarbonate for blood pH.
- Effect
- No Benefit
RCTEffect of 8-Week β-Alanine Supplementation on CRP, IL-6, Body Composition, and Bio-Motor Abilities in Elite Male Basketball Players2022n=10
An 8-week RCT of 20 elite male basketball players found 6.4 g/day beta-alanine lowered CRP and IL-6 and improved anaerobic peak power versus placebo.
- Effect
- Benefit
- Dose
- 6.4 g/day
- Population
- Men
- Participants
- 10
- Avg age
- ~23
RCTEffect of Beta-Alanine Supplementation on Exercise-Induced Cell Damage and Lactate Accumulation in Female Basketball Players: A Randomized, Double-Blind Study2022
A 4-week double-blind RCT of 22 female basketball players found 6.4 g/day beta-alanine reduced post-exercise lactate but did not improve performance or oxidative damage markers.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 6.4 g/day
- Population
- Female athletes
- Avg age
- 21.7±1.2
RCTEffects of Four Weeks of Beta-Alanine Supplementation Combined with One Week of Creatine Loading on Physical and Cognitive Performance in Military Personnel (Additional Ingredient)2022n=10
A 28-day RCT of 20 military men found adding 7-day creatine loading to 6.4 g/day beta-alanine improved vertical jump, testosterone, physical performance, and cognitive processing versus beta-alanine alone.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 6.4 g/day
- Population
- Men
- Participants
- 10
- Avg age
- 21.5±1.5
Reduced Dose of Beta-Alanine Is Sufficient to Maintain Performance in Repeated Sprints2022
A study of 44 trained men found 6.4 g/day beta-alanine for 28 days raised repeated-sprint power, and a 1.2 g/day maintenance dose preserved performance after loading.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 1.2 g/day
- Population
- Men
- Avg age
- 23.9±3.8
RCTBeta-alanine did not improve high-intensity performance throughout simulated road cycling2021n=11
An RCT of 17 cyclists found 28 days of 6.4 g/day beta-alanine raised muscle carnosine 9.4 mmol/kg but did not improve sprint performance or 4-km uphill time trial.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 6.4 g/day
- Population
- Athletes
- Participants
- 11
- Avg age
- ~38
RCTBeta-Alanine Supplementation and Sport Climbing Performance2021n=12
A 4-week RCT of 15 climbers found beta-alanine 4 g/day increased campus-board slaps and improved ~1-minute traverse performance but not shorter hard traverses.
- Effect
- Benefit
- Dose
- 4.0 g/day
- Population
- Athletes
- Participants
- 12
MetaEffects of beta-alanine supplementation on Yo-Yo test performance: A meta-analysis2021n=10
A meta-analysis of 10 athlete studies found beta-alanine improved Yo-Yo test performance when supplementation lasted 6–12 weeks and level 2 variants were used.
- Effect
- Benefit
- Duration
- 6–12 weeks
- Population
- Athletes
- Participants
- 10
RCTOne-Week High-Dose β-Alanine Loading Improves World Tour Cyclists' Time-Trial Performance2021
A 1-week study of World Tour cyclists found high-dose sustained-release beta-alanine (20 g/day) improved 10-minute time-trial power, distance, and lactate during overreaching training.
- Effect
- Benefit
- Duration
- 1 week
- Dose
- 20 g/day
- Population
- Athletes
RCTThe effect of β-alanine supplementation on high intensity cycling capacity in normoxia and hypoxia2021n=10
A 28-day crossover RCT of 19 men found 6.4 g/day beta-alanine did not improve high-intensity cycling capacity in normoxia or hypoxia despite expected carnosine loading.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 6.4 g/day
- Participants
- 10
RCTBeta-alanine fails to improve on 5000 m running time despite increasing PAT1 expression in long-distance runners2020
A 4-week RCT of 16 long-distance runners found 4.8 g/day beta-alanine increased PAT1 expression but did not significantly improve 5,000 m run time.
- Effect
- No Benefit
- Dose
- 4.8 g/day
- Population
- Athletes
MetaEffects of Beta-Alanine Supplementation on Physical Performance in Aerobic-Anaerobic Transition Zones: A Systematic Review and Meta-Analysis2020
A 2020 systematic review and meta-analysis examined beta-alanine in aerobic-anaerobic transition zones, but no abstract text is available to report specific outcomes.
RCTShort-Duration Beta-Alanine Supplementation Did Not Prevent the Detrimental Effects of an Intense Preparatory Period on Exercise Capacity in Top-Level Female Footballers2020n=12
A 3-week RCT of 24 elite female footballers found 6.4 g/day beta-alanine did not prevent declines in Yo-Yo IR1 performance during an intense preparatory camp.
- Effect
- No Benefit
- Duration
- 3 weeks
- Dose
- 6.4 g/day
- Population
- Women
- Participants
- 12
- Avg age
- ~18
Systematic reviewThe Muscle Carnosine Response to Beta-Alanine Supplementation: A Systematic Review With Bayesian Individual and Aggregate Data E-Max Model and Meta-Analysis2020n=99
A Bayesian meta-analysis of muscle carnosine studies found beta-alanine raises carnosine nonlinearly and that 99.3% of individuals respond, with no sex difference in response magnitude.
- Participants
- 99
RCTBeta-alanine supplementation improves isometric, but not isotonic or isokinetic strength endurance in recreationally strength-trained young men2019n=9
A 4-week RCT of 20 trained men found 6.4 g/day beta-alanine improved isometric but not isotonic or isokinetic strength endurance versus placebo.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 6.4 g/day
- Population
- Men
- Participants
- 9
RCTComparison of sustained-release and rapid-release β-alanine formulations on changes in skeletal muscle carnosine and histidine content and isometric performance following a muscle-damaging protocol2019
A 28-day RCT found sustained-release beta-alanine raised muscle carnosine 50% versus 38% for rapid-release and attenuated isometric fatigue versus placebo, with less paresthesia on sustained-release.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 6 g/day
- Population
- Adults
RCTEffects of beta-alanine supplementation on muscle function during recovery from resistance exercise in young adults2019n=12
A 28-day RCT of 24 young adults found 4.8 g/day beta-alanine did not improve repetitions, soreness, or CK recovery after high-intensity resistance exercise versus placebo.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 4.8 g/day
- Population
- Young adults
- Participants
- 12
- Avg age
- 22±5
RCTEffects of β-alanine and sodium bicarbonate supplementation on the estimated energy system contribution during high-intensity intermittent exercise2018n=19
An RCT of 71 cyclists found 28 days of beta-alanine did not improve 30-kJ time trial performance, though sodium bicarbonate increased estimated glycolytic contribution during high-intensity intervals.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 0.3 g/kg
- Population
- Athletes
- Participants
- 19
RCTEffects of β-alanine supplementation during a 5-week strength training program: a randomized, controlled study2018n=15
A 5-week RCT of 15 athletes found 6.4 g/day beta-alanine increased average power at 1RM and total training volume versus placebo during strength training.
- Effect
- Benefit
- Duration
- 5 weeks
- Dose
- 6.4 g/day
- Population
- Athletes
- Participants
- 15
- Avg age
- 21.85±1.6
RCTThe effect of two β-alanine dosing strategies on 30-minute rowing performance: a randomized, controlled trial2018n=27
A 4–8-week RCT of 27 rowers found 2.4 g/day beta-alanine increased 30-min rowing distance and average power in the daily-dose group, with no clear benefit from alternate-day 4.8 g dosing.
- Effect
- No Benefit
- Duration
- 4–8 weeks
- Dose
- 2.4 g/day
- Population
- Men
- Participants
- 27
- Avg age
- 24±2
RCTBeta-alanine supplementation enhances judo-related performance in highly-trained athletes2017
A 4-week RCT of highly trained judo athletes found 6.4 g/day beta-alanine increased throw count during special fitness tests and raised post-exercise lactate versus placebo.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 6.4 g/day
- Population
- Athletes
RCTBeta-Alanine Supplementation Improves Throwing Velocities in Repeated Sprint Ability and 200-m Swimming Performance in Young Water Polo Players2017
A 6-week RCT of 15 young water polo players found 6.4 g/day beta-alanine improved throwing velocity, 200-m swim time, and repeated-sprint performance.
- Effect
- Benefit
- Dose
- 6.4 g/day
RCTSix weeks of β-alanine supplementation did not enhance repeated-sprint ability or technical performances in young elite basketball players2017
A 6-week RCT of 27 elite junior basketball players found beta-alanine did not improve repeated sprints, technical performance, or Yo-Yo IR1 versus placebo.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 6.4 g/day
- Population
- Athletes
RCTEffects of 28-Day Beta-Alanine Supplementation on Isokinetic Exercise Performance and Body Composition in Female Masters Athletes2016
A 28-day RCT of female masters athletes found beta-alanine improved late-phase isokinetic work and peak torque versus placebo during lower-body testing.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 3.2 g/day beta-alanine
- Population
- Female athletes
RCTEffects of β-Alanine on Body Composition and Performance Measures in Collegiate Women2016
An 8-week RCT of 16 untrained collegiate women found beta-alanine plus resistance training increased leg-press repetitions at 65% 1RM but did not add body-composition or maximal-strength benefits beyond training.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 3.4 g/session beta-alanine
- Population
- Female athletes
RCTThe effect of β-alanine supplementation on cycling time trials of different length2016
A 4-week RCT of trained cyclists found 6.4 g/day beta-alanine extended supramaximal time to exhaustion 17.6 s and may improve 4-km time trial by 7.8 s, but not 1- or 10-km performance.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 6.4 g/day
- Population
- Athletes
- Avg age
- 24.8±6.7
Metaβ-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis2016n=1,461
A meta-analysis of 40 studies in 1,461 participants found beta-alanine improved exercise capacity (effect size 0.18), with larger benefits for 0.5–10 minute efforts and when co-supplemented with sodium bicarbonate.
- Effect
- Benefit
- Population
- Athletes
- Participants
- 1,461
RCTEffects of Acute Beta-Alanine Supplementation on Anaerobic Performance in Trained Female Cyclists2015
An acute RCT of trained female cyclists found a single 1.6 g beta-alanine dose lowered perceived exertion but did not improve Wingate performance.
- Effect
- No Benefit
- Dose
- 1.6 g/day
- Population
- Female athletes
- Avg age
- 26.6±1.3
RCTIncremental effects of 28 days of beta-alanine supplementation on high-intensity cycling performance and blood lactate in masters female cyclists2015n=11
A 28-day RCT of 11 female masters cyclists found beta-alanine increased cycling time to exhaustion 23% and total work 21% and lowered recovery lactate versus placebo.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 3.2 g/day beta-alanine
- Population
- Female athletes
- Participants
- 11
- Avg age
- 53.3±1
RCTThe effects of beta alanine plus creatine administration on performance during repeated bouts of supramaximal exercise in sedentary men2015
An RCT of sedentary men found beta-alanine plus creatine maintained mean power better across repeated Wingate tests than placebo or creatine alone.
- Effect
- Benefit
- Dose
- 5 g/day
- Population
- Men
- Ages
- 20–22
RCTβ-Alanine ingestion increases muscle carnosine content and combat specific performance in soldiers2015n=9
A 30-day RCT of 18 soldiers found 6 g/day beta-alanine raised muscle carnosine and improved 50-m casualty carry time and serial subtraction test performance versus placebo.
- Effect
- Benefit
- Duration
- 30 days
- Dose
- 6.0 g/day
- Participants
- 9
- Avg age
- 19.6±0.5
RCTβ-Alanine Supplementation Does Not Augment the Skeletal Muscle Adaptive Response to 6 Weeks of Sprint Interval Training2015n=12
A 10-week sprint-interval RCT of 24 men found beta-alanine raised muscle carnosine 33–52% but did not further improve VO2peak, 250-kJ time trial, or training adaptations versus placebo.
- Effect
- No Benefit
- Duration
- 10 weeks
- Dose
- 3.2 g/day
- Population
- Men
- Participants
- 12
RCTβ-Alanine supplementation slightly enhances repeated plyometric performance after high-intensity training in humans2015
An 8-week RCT found 5.6 g/day beta-alanine with plyometric training improved repeated jump fatigue performance and raised post-exercise lactate versus placebo.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 5.6 g/day
- Population
- Athletes
Clinical trialBeta-alanine supplementation improves jumping power and affects severe-intensity performance in professional alpine skiers2014
In 9 male elite alpine skiers, 4.8 g/day beta-alanine for 5 weeks improved countermovement jump power (~7%) and performance in the last third of a 90-s box jump test versus placebo.
- Effect
- Benefit
- Duration
- 5 weeks
- Dose
- 4.8 g/day
- Population
- Men
Controlled trialEffect of sodium bicarbonate and Beta-alanine on repeated sprints during intermittent exercise performed in hypoxia2014
In recreationally active adults, 5 weeks of beta-alanine (6.4 g/day) did not improve mean or peak power during repeated sprints in hypoxia, alone or combined with acute sodium bicarbonate.
- Effect
- No Benefit
- Duration
- 5 weeks
- Dose
- 6.4 g/day
- Population
- Adults
RCTEffects of beta-alanine supplementation and interval training on physiological determinants of severe exercise performance2014n=16
A 28-day RCT of 16 men found beta-alanine before high-intensity interval training increased aerobic energy contribution and reduced muscle lactate during severe cycling, without extra training gains.
- Effect
- Benefit
- Population
- Men
- Participants
- 16
RCTThe effect of β-alanine and NaHCO3 co-ingestion on buffering capacity and exercise performance with high-intensity exercise in healthy males2014n=5
In 8 healthy men, 4.8–6.4 g/day beta-alanine for 6 weeks raised muscle carnosine and increased time to exhaustion during high-intensity cycling by 14–16% versus placebo; adding sodium bicarbonate did not add further benefit.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 4.8 g/day
- Population
- Men
- Participants
- 5
- Avg age
- ~26.2
RCTAdditive effects of beta-alanine and sodium bicarbonate on upper-body intermittent performance2013n=37
In 37 judo/jiu-jitsu athletes, 4 weeks of beta-alanine or sodium bicarbonate each increased upper-body Wingate total work by ~7–8%; combined supplementation produced an additive ~14% increase.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 500 mg/kg
- Population
- Athletes
- Participants
- 37
- Avg age
- ~26
RCTEffect of Beta alanine and sodium bicarbonate supplementation on repeated-sprint performance2013n=24
In 24 team-sport athletes, acute sodium bicarbonate improved repeated-sprint performance more than beta-alanine alone or combined beta-alanine plus sodium bicarbonate.
- Effect
- No Benefit
- Duration
- 28 days
- Population
- Athletes
- Participants
- 24
RCTEffect of beta-alanine supplementation on 800-m running performance2013n=18
In 18 recreational male runners, 28 days of beta-alanine (80 mg/kg/day) significantly improved 800-m race time by ~3.6 s versus placebo, with the largest gains at the 400-m split.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 80 mg/kg
- Population
- Athletes
- Participants
- 18
RCTEffect of beta-alanine, with and without sodium bicarbonate, on 2000-m rowing performance2013
In 20 trained rowers, 28 days of beta-alanine (6.4 g/day) was very likely to improve 2,000-m rowing time by ~6.4 s; acute sodium bicarbonate added a small (~1.1 s) extra benefit.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 6.4 g/day
- Avg age
- ~23
RCTEffects of beta-alanine supplementation on sprint endurance2013n=11
In 21 anaerobically trained men, 5 weeks of beta-alanine (4–6 g/day) did not significantly improve time to exhaustion during treadmill sprints at 115% or 140% VO2max.
- Effect
- No Benefit
- Duration
- 5 weeks
- Dose
- 4 g/day
- Population
- Athletes
- Participants
- 11
RCTThe effect of beta-alanine supplementation on isokinetic force and cycling performance in highly trained cyclists2013n=8
In 16 highly trained cyclists, 4 weeks of beta-alanine (65 mg/kg/day) significantly increased isokinetic knee extension power and reduced fatigue index versus placebo, with a non-significant trend toward better 4-min cycling power.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 65 mg/kg
- Population
- Athletes
- Participants
- 8
- Avg age
- 24±7
RCTThe effects of beta-alanine supplementation on physical working capacity at heart rate threshold2013n=15
In 30 adults, 28 days of beta-alanine raised physical working capacity at heart rate threshold by ~24 W versus ~11 W with placebo (P=0.001), without improving VO2 peak or time to exhaustion.
- Effect
- Benefit
- Duration
- 4 days
- Population
- Adults
- Participants
- 15
- Avg age
- ~21
RCTEffect of 10 week beta-alanine supplementation on competition and training performance in elite swimmers2012n=23
In 41 elite/sub-elite swimmers, 10 weeks of beta-alanine (4.8 g/day loading, then 3.2 g/day) had unclear effects on competition times and minimal impact on training performance in real-world settings.
- Effect
- No Benefit
- Duration
- 10 weeks
- Dose
- 4.8 g/day
- Population
- Women
- Participants
- 23
- Avg age
- 21.7±2.8
RCTEffect of beta-alanine supplementation on 2000-m rowing-ergometer performance2012n=16
In 16 well-trained male rowers, 28 days of beta-alanine (~80 mg/kg/day, ~7 g/day) did not conclusively improve 2,000-m ergometer performance (p=0.055), though split improvements occurred at 750 m and 1,000 m.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 80 mg/kg
- Population
- Men
- Participants
- 16
Controlled trialEffect of beta-alanine supplementation on repeated sprint performance during the Loughborough Intermittent Shuttle Test2012
In 36 game players, 4 weeks of beta-alanine did not improve repeated sprint times during the Loughborough Intermittent Shuttle Test; neither group showed sprint fatigue before supplementation.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 36 g/day
MetaEffects of β-alanine supplementation on exercise performance: a meta-analysis2012n=360
A meta-analysis of 15 trials (360 participants) found beta-alanine improved exercise capacity lasting 60–240 s (P=0.001) with a median effect of ~2.85%, but not exercise lasting under 60 s.
- Effect
- Benefit
- Dose
- 179 g/day
- Participants
- 360
RCTHigh-velocity intermittent running: effects of beta-alanine supplementation2012n=26
In 50 recreationally trained adults, beta-alanine supplementation did not improve critical velocity, anaerobic running capacity, or time to exhaustion during 2–5 min runs at 90–110% peak velocity.
- Effect
- No Benefit
- Dose
- 800 mg/day
- Population
- Women
- Participants
- 26
Controlled trialEffect of β-alanine plus sodium bicarbonate on high-intensity cycling capacity2011
In 20 men, 4 weeks of beta-alanine (6.4 g/day) increased high-intensity cycling time to exhaustion by ~12%; adding sodium bicarbonate gave a further ~4% increase that was not statistically significant.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 6.4 g/day
- Avg age
- 25±5
RCTSix weeks of high-intensity interval training with and without beta-alanine supplementation for improving cardiovascular fitness in women2010n=19
In 44 women doing 6 weeks of HIIT, beta-alanine supplementation increased body mass but did not add to VO2 peak or ventilatory threshold gains beyond placebo or control.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 1.5 g/day
- Population
- Women
- Participants
- 19
- Avg age
- 21.8±3.7
Clinical trialThe effect of beta-alanine supplementation on power performance during repeated sprint activity2010n=10
In 19 active college men, 5 weeks of beta-alanine (4–6 g/day) did not improve peak or mean horizontal power or fatigue during repeated 5-s treadmill sprints versus placebo.
- Effect
- No Benefit
- Duration
- 5 weeks
- Dose
- 4 g/day
- Population
- Men
- Participants
- 10
Effects of 28 days of resistance exercise and consuming a commercially available pre-workout supplement, NO-Shotgun(R), on body composition, muscle strength and mass, markers of satellite cell activation, and clinical safety markers in males2009
In 18 non-resistance-trained men, 28 days of a beta-alanine–containing pre-workout (NO-Shotgun) plus training increased fat-free mass, bench press strength, and myofibrillar protein more than placebo plus training.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 27 g/day
- Population
- Resistance-trained men
- Avg age
- ~23
RCTEffects of beta-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women2007n=22
In 22 women, 28 days of beta-alanine delayed neuromuscular fatigue (PWCFT +13.9%) and raised ventilatory threshold (+12.6%) and time to exhaustion during cycling, without changing VO2 max.
- Effect
- Benefit
- Duration
- 28 days
- Population
- Women
- Participants
- 22
- Avg age
- ~27
L-CitrullineView supplement →
Consider purchase·★★★★★
How we scored this▸
- Some small studies suggest that taking L-citrulline before exercise may help reduce tiredness and muscle soreness, and can slightly improve strength.
- The best results are usually seen with 8–12 g of L-citrulline malate taken about 1–2 hours before exercise, or with smaller doses of L-citrulline in drinks like watermelon juice.
- For aerobic activities like running or cycling, results are mixed.
- Some studies found no clear benefit, while others showed modest improvements in power, endurance, or cycling performance after a week of daily use at 2–6 g.
- When combined with L-arginine, L-citrulline may work better to improve athletic performance.
- For example, in soccer players, 1.2 g of each taken daily for a week improved cycling power and reduced the feeling of effort.
- Because the results differ depending on the type of exercise, dose, and form used, the overall benefits are still uncertain.
Browse 15 studies·2 meta-analyses
RCTEffect of different sports drink compositions on endurance performance and substrate oxidation: a randomized, double-blind, placebo-controlled crossover study in trained athletes2025
In 12 trained endurance athletes, sequential testing of sports drink components found no clear additive endurance benefit from combined formulations versus individual ingredients.
- Effect
- No Benefit
- Population
- Athletes
- Ages
- 20–35
RCTThe effect of quercetin and citrulline on cycling time trial performance2024
In cyclists, 28 days of quercetin plus citrulline supplementation did not significantly improve time-trial performance versus placebo.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 500 mg
- Population
- Athletes
RCTAcute citrulline-malate supplementation is ineffective during aerobic cycling and subsequent anaerobic performance in recreationally active males2021
In 28 recreationally active males, acute 8 g citrulline malate did not improve aerobic cycling or subsequent anaerobic performance versus placebo.
- Effect
- No Benefit
- Dose
- 8 g/day
- Population
- Active males
- Avg age
- ~20.9±2.8
MetaAcute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-Analysis2021n=101
A meta-analysis across strength-training studies (101 participants) found citrulline malate taken before training increased total repetitions to failure versus placebo.
- Effect
- Benefit
- Dose
- 6–8 g/day
- Population
- Healthy adults
- Participants
- 101
RCTThe Effects of L-Citrulline on Blood-Lactate Removal Kinetics Following Maximal-Effort Exercise2021
An RCT found L-citrulline did not significantly accelerate blood-lactate removal after maximal-effort exercise versus placebo.
- Effect
- No Benefit
MetaEffect of citrulline on post-exercise rating of perceived exertion, muscle soreness, and blood lactate levels: A systematic review and meta-analysis2020n=206
A meta-analysis (206 participants) found citrulline reduced post-exercise muscle soreness and blood lactate, though effects on perceived exertion were inconsistent.
- Effect
- Benefit
- Dose
- 8 g/day
- Population
- Athletes
- Participants
- 206
RCTOne Week of L-Citrulline Supplementation Improves Performance in Trained Cyclists2020
In trained cyclists, 6 g/day L-citrulline for 7 days improved cycling performance versus placebo.
- Effect
- Benefit
- Duration
- 7 days
- Dose
- 6 g/day
- Population
- Athletes
- Avg age
- ~24±3
RCTA combination of oral L-citrulline and L-arginine improved 10-min full-power cycling test performance in male collegiate soccer players: a randomized crossover trial2019n=20
In 24 male soccer players, 1.2 g/day L-citrulline plus L-arginine for 6 days improved 10-minute full-power cycling test performance versus placebo.
- Effect
- Benefit
- Duration
- 6 days
- Dose
- 1.2 g/day
- Population
- Athletes
- Participants
- 20
- Ages
- 18–25
RCTConsumption of Watermelon Juice Enriched in l-Citrulline and Pomegranate Ellagitannins Enhanced Metabolism during Physical Exercise2017n=19
In 19 men, a single dose of watermelon juice enriched with L-citrulline and pomegranate ellagitannins improved metabolism during high-intensity half-squat exercise versus control.
- Effect
- Benefit
- Population
- Men
- Participants
- 19
RCTAcute Citrulline-Malate Supplementation and High-Intensity Cycling Performance2016
Acute citrulline malate supplementation did not improve high-intensity cycling performance or acid-base balance versus placebo.
- Effect
- No Benefit
- Dose
- 12 g/day
RCTOral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study2016
In 22 trained men, 2.4 g/day L-citrulline for 7 days enhanced cycling time-trial performance versus placebo.
- Effect
- Benefit
- Duration
- 7 days
- Dose
- 2.4 g/day
- Population
- Athletes
- Ages
- 20–39
RCTl-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans2015n=10
In 10 healthy men in a crossover trial, 6 g/day L-citrulline for 7 days improved O2 uptake kinetics and high-intensity exercise performance versus placebo.
- Effect
- Benefit
- Duration
- 7 days
- Dose
- 6 g/day
- Population
- Healthy adults
- Participants
- 10
RCTThe effect of l-citrulline and watermelon juice supplementation on anaerobic and aerobic exercise performance2015n=11
In 22 participants, a single pre-exercise dose of L-citrulline, watermelon juice, or placebo did not significantly improve anaerobic or aerobic performance or VO2max.
- Effect
- No Benefit
- Dose
- 6 g/day
- Participants
- 11
RCTCitrulline malate enhances athletic anaerobic performance and relieves muscle soreness2010n=41
In 41 men, a single 8 g citrulline malate dose before bench press increased repetitions to fatigue and reduced muscle soreness at 24 and 48 hours versus placebo.
- Effect
- Benefit
- Dose
- 8 g/day
- Population
- Athletes
- Participants
- 41
L-citrulline reduces time to exhaustion and insulin response to a graded exercise test2006n=17
In 17 healthy adults, L-citrulline supplementation extended graded treadmill time to exhaustion and reduced insulin response during exercise versus placebo.
- Effect
- No Benefit
- Dose
- 3 g/day
- Population
- Adults
- Participants
- 17
RhodiolaView supplement →
Consider purchase·★★★★★
How we scored this▸
- Research on Rhodiola and exercise performance shows mixed results. Some small studies have found that taking Rhodiola shortly before exercise can help people exercise longer or feel less tired, especially during cycling tests.
- In these studies, products containing certain Rhodiola extracts (3% rosavins and 1% salidroside) given in doses of about 200–500 mg were linked to small improvements in endurance and performance.
- Other studies found that longer-term use, or use without a pre-exercise dose, did not improve running, muscle strength, or recovery. When Rhodiola was combined with other ingredients such as cordyceps or maral root, there was no extra benefit. Overall, Rhodiola might give a small, short-term boost in performance for some people, but results are not consistent.
Browse 15 studies·7 meta-analyses
RCTEffects of the Combined Supplementation of Caffeine and Rhodiola Rosea with Resistance Training on Lower Limb Explosive Power in Male Volleyball Players2025n=12
A systematic review found limited RCT evidence that herbs including Rhodiola raise testosterone in men, with most trials small and heterogeneous.
- Effect
- Benefit
- Population
- Athletes
- Participants
- 12
- Ages
- 18–23
RCTThe Impact of Rhodiola Rosea Extract on Strength Performance in Alternative Bench-Press and Bench-Pull Exercises Under Resting and Mental Fatigue Conditions: A Randomized, Triple-Blinded, Placebo-Controlled, Crossover Trial2025n=18
In 139 acne patients, Saccharomyces cerevisiae (Perenterol) was rated very good/good in 74.3% versus 21.7% on placebo over up to 5 months.
- Effect
- Benefit
- Duration
- 4 days
- Population
- Women
- Participants
- 18
- Ages
- 18–40
MetaCombined effects of Rhodiola rosea and caffeine supplementation on aerobic endurance and muscle explosiveness: a synergistic approach2024n=48
A meta-analysis of 17 outpatient RCTs found probiotics reduced antibiotic-associated diarrhea incidence (RR 0.54) versus placebo or no treatment.
- Effect
- Benefit
- Duration
- 30 days
- Population
- Athletes
- Participants
- 48
- Ages
- 8–9
Synergistic Effect of Rhodiola rosea and Caffeine Supplementation on the Improvement of Muscle Strength and Muscular Endurance: A Pilot Study for Rats, Resistance Exercise-Untrained and -Trained Volunteers2023n=12
In 368 hospitalized adults on antibiotics, Saccharomyces boulardii did not significantly reduce antibiotic-associated or C. difficile diarrhea versus placebo.
- Effect
- No Benefit
- Duration
- 30 days
- Dose
- 262.7 mg/kg
- Population
- Men
- Participants
- 12
RCTEffects of Short-Term Golden Root Extract (Rhodiola rosea) Supplementation on Resistance Exercise Performance2021n=10
A meta-analysis found Saccharomyces boulardii reduced antibiotic-associated diarrhea risk versus control, with moderate-quality evidence in adults and children.
- Effect
- No Benefit
- Duration
- 3 days
- Dose
- 1500 mg/day
- Population
- Male weightlifters
- Participants
- 10
RCTThe Acute Effects of a Multi-Ingredient Herbal Supplement on Performance Fatigability: A Double-Blind, Randomized, and Placebo-Controlled Trial2021
A meta-analysis found probiotics, including S. boulardii, reduced pediatric antibiotic-associated diarrhea versus placebo, though strain effects varied.
- Effect
- No Benefit
- Dose
- 175–350 mg Rhodiola+carthamoides
- Population
- Children
- Avg age
- 22.3±4.1
RCTEffects of Rhodiola rosea supplementation on mental performance, physical capacity, and oxidative stress biomarkers in healthy men2019n=26
In hospitalized patients on antibiotics, S. boulardii reduced AAD incidence versus placebo in a single-center randomized trial.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 600 mg/day
- Population
- Men
- Participants
- 26
RCTEffects of short-term Rhodiola Rosea (Golden Root Extract) supplementation on anaerobic exercise performance2019
A meta-analysis found probiotics reduced antibiotic-associated diarrhea odds by about 42% versus placebo across double-blind RCTs.
- Effect
- Benefit
- Duration
- 3 days
- Dose
- 500 mg/day
RCTThe Effect of Acute Rhodiola rosea Ingestion on Exercise Heart Rate, Substrate Utilisation, Mood State, and Perceptions of Exertion, Arousal, and Pleasure/Displeasure in Active Men2014
A systematic review found probiotics reduced antibiotic-associated diarrhea risk, with Saccharomyces boulardii among the better-supported strains.
- Effect
- Benefit
- Dose
- 3 mg/kg
- Avg age
- 26±6
RCTThe effects of an acute dose of Rhodiola rosea on endurance exercise performance2013n=18
A meta-analysis found probiotics reduced antibiotic-associated diarrhea and possibly C. difficile disease, with S. boulardii showing consistent benefit.
- Effect
- Benefit
- Duration
- 2–7 days
- Dose
- 3 mg/day
- Participants
- 18
RCTEffects of chronic Rhodiola Rosea supplementation on sport performance and antioxidant capacity in trained male: preliminary results2010
In military patients on antibiotics, prophylactic S. boulardii reduced antibiotic-associated diarrhea versus placebo.
- Effect
- Benefit
- Duration
- 4 weeks
- Population
- Athletes
RCTFailure of Rhodiola rosea to alter skeletal muscle phosphate kinetics in trained men2007
A meta-analysis confirmed S. boulardii reduces antibiotic-associated diarrhea in children and adults versus placebo.
- Effect
- No Benefit
- Duration
- 4 days
- Dose
- 1500 mg/day R. rosea
- Population
- Children
- Ages
- 19–39
RCTCordyceps sinensis- and Rhodiola rosea-based supplementation in male cyclists and its effect on muscle tissue oxygen saturation2005n=269
In 269 children on broad-spectrum antibiotics, S. boulardii 250 mg twice daily reduced diarrhea incidence versus placebo.
- Effect
- No Benefit
- Dose
- 500 mg/day
- Population
- Men
- Participants
- 269
RCTAcute Rhodiola rosea intake can improve endurance exercise performance2004n=24
In 466 pediatric antibiotic recipients, S. boulardii reduced antibiotic-associated diarrhea versus placebo, especially with longer baseline sleep latency.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 200 mg/day
- Population
- Healthy adults
- Participants
- 24
RCTA double-blind, placebo-controlled pilot study of the stimulating and adaptogenic effect of Rhodiola rosea SHR-5 extract on the fatigue of students caused by stress during an examination period with a repeated low-dose regimen2000
A meta-analysis of 9 probiotic trials found S. boulardii and lactobacilli reduced antibiotic-associated diarrhea versus placebo.
- Effect
- Benefit
- Duration
- 20 days
Acetyl-L-CarnitineView supplement →
Consider purchase·★★★★★
How we scored this▸
- Taking L-carnitine might enhance performance during hard exercise by helping you produce more power, feel less fatigue, and do more work.
- The benefits seem to occur mainly during high-intensity activity above 80% VO2 max when taken 60–90 minutes before exercise.
- It does not appear to help much for lighter or moderate exercise (50–79% VO2 max).
Browse 2 studies
Systematic reviewEffect of Acute and Chronic Oral L-Carnitine Supplementation on Exercise Performance Based on the Exercise Intensity: A Systematic Review2021
A systematic review of 11 studies found that an acute dose of 3 to 4 grams L-carnitine taken 60 to 90 minutes before a high intensity exercise (>80% VO2 max) improved peak power, average power, lactate threshold and reduced perceived exertion. A dose ranging from 2 to 2.72 g/day L-carnitine taken for 9 to 24 weeks reduced lactate accumulation, reduced perceived exertion, increased work capacity in all out efforts, increased peak power in a Wingate test, and increased number of repetitions and volume lifted in leg press exercises. However, there was no effect from a dose of 2.72 to 3 g/day L-carnitine (4 to 24 weeks) in exercise of moderate intensity (50-79% VO2 max).
- Effect
- Benefit
- Duration
- 4–24 weeks
- Dose
- 2.72 g/day
- Population
- Athletes
RCTEffects of nine weeks L-Carnitine supplementation on exercise performance, anaerobic power, and exercise-induced oxidative stress in resistance-trained males2018n=12
In 23 resistance-trained men, 9 weeks of L-carnitine 2 g/day increased bench press volume and peak power and reduced post-exercise blood lactate and oxidative stress markers versus placebo.
- Effect
- Benefit
- Duration
- 9 weeks
- Dose
- 2 g/day
- Population
- Resistance-trained men
- Participants
- 12
- Ages
- 18–40
Branched Chain Amino Acids (BCAAs)View supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Small studies show that taking branched-chain amino acids (BCAAs) doesn’t usually improve athletic performance like strength or running and cycling times.
- However, BCAAs may help reduce how hard exercise feels and lessen fatigue, especially during long or intense workouts, exercise in the heat, or after your body’s energy stores are low.
- These effects can be stronger when BCAAs are taken with other supplements like arginine or green tea.
- Research varies on how much to take and when, and results are not clear because studies use different doses and methods.
Browse 28 studies·1 meta-analysis
RCTBranched-chain amino acid supplementation enhances substrate metabolism, exercise efficiency and reduces post-exercise fatigue in active young males2025n=8
An crossover RCT of 11 active men found 3 days of BCAA supplementation raised fat oxidation during submaximal cycling and improved time to exhaustion at 80% VO2max versus placebo.
- Effect
- Benefit
- Population
- Men
- Participants
- 8
RCTBranched-chain amino acid supplementation improves cycling performance in untrained cyclists2021
A double-blind crossover in 18 recreationally active men found acute BCAA reduced cycling time-trial completion time and perceived exertion without changing neuromuscular fatigue markers.
- Effect
- Benefit
- Dose
- 0.084 g/day
- Population
- Athletes
- Avg age
- 25±5
MetaThe effect of branched-chain amino acid on muscle damage markers and performance following strenuous exercise: a systematic review and meta-analysis2021n=479
A meta-analysis of 25 studies (479 participants, mean age 24) found BCAA lowered creatine kinase and muscle soreness 48 hours post-exercise but did not clearly improve performance recovery.
- Effect
- No Benefit
- Participants
- 479
- Avg age
- ~24
Controlled trialBranched-chain amino acids do not improve muscle recovery from resistance exercise in untrained young adults2019n=12
An RCT of 24 untrained young adults found 5 days of BCAA supplementation did not improve repetitions, soreness, or jump performance after resistance exercise versus placebo.
- Effect
- No Benefit
- Duration
- 5 days
- Population
- Young adults
- Participants
- 12
- Avg age
- 24±4
RCTEffect of branched-chain amino acid supplementation on recovery following acute eccentric exercise2018n=20
An RCT of 20 men found BCAA reduced muscle soreness at 48 hours after eccentric exercise, but effects on CK, strength, and jump performance were negligible on a ~1.2 g/kg/day protein diet.
- Effect
- No Benefit
- Dose
- 1.2 g/kg
- Participants
- 20
- Avg age
- 22.3±1.5
RCTThe effect of branched-chain amino acids, citrulline, and arginine on high-intensity interval performance in young swimmers2018
A crossover RCT of 16 young swimmers found pre-exercise BCAA plus arginine and citrulline (0.085, 0.05, and 0.05 g/kg) shortened average 50 m sprint times during high-intensity intervals.
- Effect
- Benefit
- Dose
- 0.05 g/kg/day
- Population
- Women
- Avg age
- ~16
RCTEffect of BCAA supplement timing on exercise-induced muscle soreness and damage: a pilot placebo-controlled double-blind study2017n=15
A pilot RCT of 15 men found pre-exercise BCAA (9.6 g/day) attenuated DOMS and exercise-induced muscle damage markers more than post-exercise BCAA over 3 days after eccentric arm exercise.
- Effect
- No Benefit
- Duration
- 3 days
- Dose
- 9.6 g/day
- Population
- Older adults
- Participants
- 15
- Avg age
- ~22
RCTThe effects of acute branched-chain amino acid supplementation on recovery from a single bout of hypertrophy exercise in resistance-trained athletes2017n=8
An RCT of 16 resistance-trained athletes found acute BCAA (0.087 g/kg) after hypertrophy squats improved isometric strength recovery, jump height, and soreness versus placebo over 48 hours.
- Effect
- Benefit
- Dose
- 0.087 g/kg/day
- Population
- Athletes
- Participants
- 8
RCTBranched-chain amino acid supplementation attenuates a decrease in power-producing ability following acute strength training2016
An RCT of 11 resistance-trained men found 20 g BCAA before and after strength training attenuated decrements in countermovement jump and shot-put power 24 hours post-session versus placebo.
- Effect
- Benefit
- Population
- Athletes
RCTBranched-chain amino acids, arginine, citrulline alleviate central fatigue after 3 simulated matches in taekwondo athletes: a randomized controlled trial2016
A crossover RCT of 12 taekwondo athletes found BCAA plus arginine and citrulline (0.17 and 0.05 g/kg) after two matches preserved reaction time during a third match versus placebo.
- Effect
- Benefit
- Dose
- 0.05 g/kg/day
- Population
- Athletes
- Avg age
- 20±0.8
RCTBranched-chain amino acids and arginine improve performance in two consecutive days of simulated handball games in male and female athletes: a randomized trial2015n=15
A crossover RCT of 22 handball players found BCAA plus arginine over 2 consecutive simulated game days improved sprint performance decline and lowered perceived exertion.
- Effect
- Benefit
- Duration
- 2 days
- Dose
- 0.17 g/kg
- Population
- Athletes
- Participants
- 15
- Avg age
- ~21
RCTA 7-day oral supplementation (7 g/day prior to competition) with branched-chain amino acids was ineffective to prevent muscle damage or improve running performance during a marathon2014n=25
An RCT of 46 marathon runners found 7 days of 5 g/day BCAA before a race did not improve running pace, muscle power, myoglobin, or muscle pain versus placebo.
- Effect
- No Benefit
- Duration
- 7 days
- Dose
- 5 g/day
- Population
- Athletes
- Participants
- 25
RCTBranched-chain amino acids supplementation enhances exercise capacity and lipid oxidation during endurance exercise after muscle glycogen depletion2011
A crossover study of 7 glycogen-depleted volunteers found 3 days of 300 mg/kg/day BCAA increased time to exhaustion 17% and enhanced fat oxidation during exhaustive exercise.
- Effect
- Benefit
- Duration
- 3 days
- Dose
- 300 mg/kg
RCTEffects of BCAA, arginine and carbohydrate combined drink on post-exercise biochemical response and psychological condition2011n=14
An RCT of 14 men found a post-exercise BCAA-arginine-carbohydrate drink raised glucose, insulin, and testosterone-to-cortisol ratio and reduced fatigue scores 120 minutes after exhaustive exercise.
- Effect
- No Benefit
- Participants
- 14
Clinical trialBranched-chain amino acid ingestion can ameliorate soreness from eccentric exercise2010n=12
An RCT of 24 men found BCAA over 3 days after eccentric knee extensions reduced flexed muscle soreness at 48 and 72 hours but did not improve strength loss or CK versus placebo.
- Effect
- No Benefit
- Duration
- 3 days
- Participants
- 12
RCTBranched-chain amino acid supplementation before squat exercise and delayed-onset muscle soreness2010
A crossover RCT of 12 untrained women found 100 mg/kg BCAA before squat exercise reduced DOMS and preserved leg force at day 3 versus placebo.
- Effect
- Benefit
- Dose
- 100 mg/kg
- Population
- Women
RCTBranched-chain amino acid supplementation attenuates muscle soreness, muscle damage and inflammation during an intensive training program2009
A crossover study of 12 long-distance runners found BCAA-enriched drinks during 3-day intensive training cut muscle soreness 32%, fatigue 24%, and CK, LDH, and elastase versus placebo.
- Effect
- Benefit
- Dose
- 20 g/day BCAA
- Population
- Athletes
RCTEffects of branched-chain amino acids supplementation on physiological and psychological performance during an offshore sailing race2008n=6
An RCT of 12 sailors during a 32-hour offshore race found high-protein BCAA supplementation reduced fatigue accumulation and prevented short-term memory decline versus standard diet.
- Effect
- Benefit
- Participants
- 6
RCTBranched-chain amino acid supplementation and indicators of muscle damage after endurance exercise2007
An RCT of 9 untrained men doing three 90-min cycling bouts found BCAA lowered CK at 4–48 hours and soreness at 24–48 hours versus placebo or carbohydrate.
- Effect
- Benefit
- Population
- Men
Controlled trialNutraceutical effects of branched-chain amino acids on skeletal muscle2006
A mechanistic review reported BCAA supplementation before squat exercise decreased DOMS and muscle fatigue in human studies, linked to reduced muscle protein breakdown during exercise.
- Effect
- Benefit
Controlled trialThe effect of acute branched-chain amino acid supplementation on prolonged exercise capacity in a warm environment (no effect)2004
An RCT of 8 men found acute BCAA before glycogen-depleted cycling in heat raised plasma BCAA and ammonia but did not extend exercise capacity versus placebo.
- Effect
- No Benefit
- Dose
- 12 g/L BCAA (1 L pre-exercise)
- Population
- Men
Controlled trialEffects of branched-chain amino acids and carbohydrate on fatigue during intermittent, high-intensity running1999
A crossover study found carbohydrate with or without 7 g BCAA prolonged intermittent shuttle running versus placebo, but BCAA added no benefit beyond carbohydrate alone.
- Effect
- No Benefit
- Dose
- 7 g
Controlled trialBranched-chain amino acids prolong exercise during heat stress in men and women1998n=13
A heat-stress trial of 13 men and women found BCAA drinks every 30 minutes prolonged cycle time to exhaustion from 137 to 153 minutes and lowered free tryptophan:BCAA ratio.
- Effect
- Benefit
- Dose
- 5 mL/kg every 30 min
- Population
- Adults
- Participants
- 13
RCTInfluence of ingesting a solution of branched-chain amino acids on perceived exertion during exercise1997
An RCT of 7 cyclists after glycogen-depleting exercise found BCAA lowered perceived exertion 7% and mental fatigue 15% during 60 min at 70% VO2max, with better Stroop performance afterward.
- Effect
- No Benefit
- Population
- Athletes
Branched-chain amino acid supplementation during repeated prolonged skiing exercises at altitude1996n=12
A field study of 24 ski mountaineers at altitude found BCAA did not significantly preserve body composition, peak power, or weight loss versus carbohydrate supplementation.
- Effect
- No Benefit
- Participants
- 12
Controlled trialEffects of glucose, glucose plus branched-chain amino acids, or placebo on bike performance over 100 km1996
A crossover study of 9 cyclists found glucose plus BCAA during a 100 km time trial did not improve finish time versus glucose or placebo, despite higher plasma BCAA and ammonia.
- Effect
- No Benefit
- Population
- Athletes
RCTIngestion of branched-chain amino acids and tryptophan during sustained exercise in man: failure to affect performance1995
An RCT of 10 endurance-trained men found sucrose drinks with tryptophan or BCAA during 70–75% VO2max cycling for ~122 min did not alter time to exhaustion or fatigue mechanisms.
- Effect
- No Benefit
- Dose
- 6–18 g/L BCAA
- Population
- Athletes
Controlled trialAdministration of branched-chain amino acids during sustained exercise — effects on performance and on plasma concentration of some amino acids1991
A crossover study found BCAA during a 30-km race or marathon improved Stroop test performance after exercise and extended marathon time in slower runners (<3.05 h) but not faster runners.
- Effect
- Benefit
- Population
- Athletes
TaurineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- The effects of taurine supplements on athletic performance are mixed but may provide small benefits in some athletes.
- Taking taurine before exercise has helped some cyclists and active people improve endurance and power output slightly, but it doesn’t always reduce tiredness or improve how hard exercise feels.
- Taurine may also boost strength and reduce muscle fatigue in people who regularly consume caffeine.
- Taurine is often included in energy drinks with other ingredients, which might help performance, but it’s hard to say how much taurine alone helps.
- More research is needed to know who benefits most from taurine.
Browse 16 studies·1 meta-analysis
RCTTaurine supplementation enhances anaerobic power in elite speed skaters: A double-blind, randomized, placebo-controlled, crossover study2023n=30
In elite speed skaters, taurine 3 g/day for 14 days improved Wingate anaerobic power versus placebo in this double-blind crossover trial.
- Effect
- Benefit
- Duration
- 14 days
- Dose
- 3 g/day
- Population
- Athletes
- Participants
- 30
- Avg age
- 23.9±2.8
RCTDoes Single or Combined Caffeine and Taurine Supplementation Improve Athletic and Cognitive Performance without Affecting Fatigue Level in Elite Boxers? A Double-Blind, Placebo-Controlled Study2022
In fatigued athletes, combined caffeine and taurine improved anaerobic performance after fatigue more than either ingredient alone in this crossover study.
- Effect
- Benefit
- Dose
- 6 mg/kg
- Population
- Elite boxers
- Avg age
- 14±1.42
RCTCombined but Not Isolated Ingestion of Caffeine and Taurine Improves Wingate Sprint Performance in Female Team-Sport Athletes Habituated to Caffeine2021
In 17 female team-sport athletes, combined caffeine and taurine improved repeated Wingate sprint performance versus placebo in this randomized trial.
- Effect
- Benefit
- Dose
- 28.6 mg/day
- Population
- Female athletes
- Avg age
- 23.4±2.1
RCTAcute taurine supplementation enhances thermoregulation and endurance cycling performance in the heat2019n=11
In 11 healthy men cycling in heat, acute taurine 50 mg/kg improved time to exhaustion and thermoregulation versus placebo.
- Effect
- Benefit
- Dose
- 50 mg/kg
- Population
- Healthy men
- Participants
- 11
RCTOral taurine improves critical power and severe-intensity exercise tolerance2019n=12
In 12 men, acute oral taurine improved critical power and severe-intensity exercise tolerance versus placebo in this crossover trial.
- Effect
- Benefit
- Dose
- 50 mg/kg
- Participants
- 12
RCTEffects of taurine on markers of muscle damage, inflammatory response and physical performance in triathletes2018
In trained triathletes, taurine supplementation did not significantly reduce post-exercise muscle damage or inflammation markers versus control.
- Effect
- No Benefit
- Duration
- 8 weeks
- Dose
- 3 g/day taurine
- Population
- Athletes
- Ages
- 25–35
RCTThe Effect of Acute Taurine Ingestion on Human Maximal Voluntary Muscle Contraction2018
In trained men, acute taurine ingestion did not significantly change maximal voluntary muscle contraction versus placebo regardless of caffeine habit.
- Effect
- No Benefit
- Dose
- 40 mg/kg
- Population
- Athletes
MetaThe Effects of an Oral Taurine Dose and Supplementation Period on Endurance Exercise Performance in Humans: A Meta-Analysis2018n=7
A systematic review found isolated oral taurine doses had inconsistent effects on endurance performance across available randomized trials.
- Effect
- Benefit
- Dose
- 6 g/day
- Participants
- 7
RCTThe Effects of Caffeine, Taurine, or Caffeine-Taurine Coingestion on Repeat-Sprint Cycling Performance and Physiological Responses2017
In team-sport players, caffeine, taurine, or combined ingestion did not significantly improve repeat-sprint cycling performance versus placebo.
- Effect
- No Benefit
- Dose
- 5 mg/kg
- Population
- Athletes
RCTAcute administration of high doses of taurine does not substantially improve high-intensity running performance and the effect on maximal accumulated oxygen deficit is unclear2016
In trained runners, acute high-dose taurine did not improve high-intensity running time to exhaustion versus placebo.
- Effect
- No Benefit
- Dose
- 6 g
- Population
- Men
- Avg age
- 25±6
RCTAdditional effects of taurine on the benefits of BCAA intake for the delayed-onset muscle soreness and muscle damage induced by high-intensity eccentric exercise2013
In young men after eccentric exercise, taurine plus BCAA reduced delayed-onset muscle soreness more than BCAA alone in this randomized trial.
- Effect
- Benefit
- Duration
- 18 days
- Dose
- 2 g/day taurine + 3.2 g/day BCAA
- Population
- Men
RCTThe effect of acute taurine ingestion on 3-km running performance in trained middle-distance runners2013
In 8 trained middle-distance runners, 1000 mg acute taurine did not improve 3-km time-trial performance versus placebo.
- Effect
- No Benefit
- Dose
- 1000 mg taurine (acute)
- Population
- Athletes
- Avg age
- ~20
RCTAcute effects of a caffeine-taurine energy drink on repeated sprint performance of American college football players2012
In college football players, a caffeine-taurine energy drink improved repeated sprint performance versus placebo in this acute trial.
- Effect
- No Benefit
- Population
- Athletes
- Avg age
- ~20
RCTSupplementation with soybean peptides, taurine, Pueraria isoflavone, and ginseng saponin complex improves endurance exercise capacity in humans2011
In exercising adults, a soybean peptide/taurine/pueraria isoflavone/ginseng capsule (STPG) for 15 days did not significantly improve exercise performance markers versus placebo.
- Effect
- No Benefit
- Duration
- 15 days
- Dose
- 2 g
- Population
- Men
RCTThe effect of acute taurine ingestion on endurance performance and metabolism in well-trained cyclists2010
In 11 well-trained cyclists, acute taurine 1.66 g did not improve 1-hour time-trial performance or metabolism versus placebo.
- Effect
- No Benefit
- Dose
- 1.66 g taurine (acute)
- Population
- Athletes
RCTImproved cycling time-trial performance after ingestion of a caffeine energy drink2009
In trained cyclists, a caffeine energy drink improved cycling time-trial performance versus placebo in this acute supplementation trial.
- Effect
- Benefit
- Dose
- 160 mg/day
- Population
- Athletes
- Avg age
- ~27
IronView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking iron supplements can help improve some aspects of exercise performance in adults, such as the ability to use oxygen during exercise, but it might not increase how long a person can exercise or reduce energy use.
- People with low iron but no anemia often feel less tired after taking iron, but their exercise capacity might not improve.
- In children, taking iron or eating more iron-rich foods for one to two months helped them run better with a lower heart rate during exercise.
- Some early studies also found that iron made them able to run longer on a treadmill.
Browse 3 studies·2 meta-analyses
Systematic reviewEfficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials2018n=1,170
A systematic review and meta-analysis of 1,170 non-anaemic iron-deficient adults found iron therapy may reduce fatigue, though benefits on physical capacity were inconsistent across trials.
- Effect
- Benefit
- Dose
- 4.01 g/day
- Population
- Adults
- Participants
- 1,170
MetaIron supplementation benefits physical performance in women of reproductive age: a systematic review and meta-analysis2014
A meta-analysis in women of reproductive age found iron supplementation improved exercise performance measures compared with control, supporting benefit in iron-deficient WRA.
- Effect
- Benefit
- Population
- Women
Systematic reviewEffect of iron supplementation on physical performance in children and adolescents: systematic review of randomized controlled trials2007
A systematic review of 3 RCTs in children aged 0–18 years found insufficient evidence that iron supplementation improves heart rate, endurance time, lactate, or oxygen consumption.
- Effect
- No Benefit
- Dose
- 7.71–7.55 mg
- Population
- Children/adolescents
- Ages
- 0–18
PhosphatidylserineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if taking phosphatidylserine helps athletic performance. In one small study with golfers, eating bars containing 200 mg phosphatidylserine daily for 6 weeks improved the number of good shots, which might help their score, but stress and heart rate stayed the same.
- Another study found that a combination supplement with phosphatidylserine (400 mg), caffeine, vitamins, minerals, and carbs helped reduce tiredness and mood problems after exercise for people who stay active. However, it didn’t improve thinking or reaction time, and it is not known which ingredient was responsible for the benefits.
Browse 5 studies
RCTPhosphatidylserine and caffeine attenuate postexercise mood disturbance and perception of fatigue in humans2013
In healthy subjects, 2 weeks of phosphatidylserine plus caffeine attenuated post-exercise mood disturbance and fatigue versus control, without changing reaction time.
- Effect
- Benefit
- Duration
- 2 weeks
- Dose
- 400 mg/day
- Population
- Healthy adults
RCTThe effect of phosphatidylserine on golf performance2007n=10
In 10 golfers, phosphatidylserine 200 mg/day for 42 days increased good ball flights (10.1 vs 7.9) and trended toward lower perceived stress versus placebo.
- Effect
- Benefit
- Duration
- 42 days
- Dose
- 200 mg/day
- Population
- Healthy adults
- Participants
- 10
RCTEffects of phosphatidylserine on exercise capacity during cycling in active males2006
A study including 14 active males found that phosphatidylserine (750 mg/day for 10 days) led to significant improvements in cycling performance as measured by time to exhaustion at 85% VO2max (7:51 +/- 1:36 to 9:51 +/- 1:42 min:s, P = 0.001). Exhaustion was defined as an inability to maintain a cadence of 60 rpm despite verbal encouragement). There were no effects on mood, serum cortisol or fat and oxygen utilisation compared to placebo.
- Effect
- Benefit
- Duration
- 10 days
- Dose
- 750 mg/day
RCTPhosphatidylserine supplementation and recovery following downhill running2006
A study including 8 recreationally active males found that phosphatidylserine (750 mg/day for 7 days, on test day, then for another 2 days) prior to and for 2 days following a downhill running exercise did not affect onset of muscle soreness or markers of muscle damage, inflammation and oxidative stress.
- Effect
- No Benefit
- Duration
- 7 days
- Dose
- 750 mg/day
Controlled trialBlunting by chronic phosphatidylserine administration of the stress-induced activation of the hypothalamo-pituitary-adrenal axis in healthy men1992n=9
In 9 healthy men, phosphatidylserine 800 mg/day for 10 days blunted ACTH and cortisol responses to exercise (p=0.003 and p=0.03) without affecting GH or PRL.
- Effect
- Benefit
- Duration
- 10 days
- Dose
- 800 mg/day
- Population
- Men
- Participants
- 9
Tongkat AliView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking Eurycoma longifolia does not appear to help with athletic performance.
- In one small study, men who took 150 mg daily for a week and again one hour before running showed no better endurance than those given a placebo.
- In another larger study, healthy men taking 300 mg of a specific extract (Physta) daily for 12 weeks did not show improved physical fitness compared with placebo.
Browse 5 studies
RCTExercise associated or not to the intake of Eurycoma longifolia improves strength and cardiorespiratory fitness in men with androgen deficiency2021n=11
An RCT of 45 men with androgen deficiency found that 6 months of concurrent training plus Eurycoma longifolia improved knee strength and reduced ADAM symptom scores versus control.
- Effect
- Benefit
- Duration
- 6 months
- Population
- Men
- Participants
- 11
- Avg age
- ~48
RCTEffects of Eurycoma Longifolia Jack Supplementation Combined with Resistance Training on Isokinetic Muscular Strength and Power, Anaerobic Power, and Urinary Testosterone: Epitestosterone Ratio in Young Males2019n=11
A study examining the effects of tongkat ali in 40 young males found that in subjects undergoing concurrent resistance training, taking 200 mg daily for 8 weeks lead to improved peak power output but not average power. Participants were assigned to one of four groups: - Control - Tongkat ali - Weight training - Tongkat ali + Weight training Tongkat ali taken alone and without resistance training did not lead to significant improvements in average or peak power in knee flexion and extension exercise.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 200 mg/day
- Participants
- 11
- Ages
- 19–25
RCTSupplementation of Eurycoma longifolia Jack Extract for 6 Weeks Does Not Affect Urinary Testosterone: Epitestosterone Ratio, Liver and Renal Functions in Male Recreational Athletes2014
A manufacturer study examining the effects of tongkat ali (Physta) on urinary testosterone: epitestosterone ratio (T:E ratio) found that supplementation at 400 mg/day for 6 weeks is unlikely to breach doping policies. There was no change in T:E ratio or markers of liver enzymes. However, further studies are required using varied doses and time periods to ensure safe guidelines. This study was supported by Biotropics Malaysia Berhad, a proprietary herbal extract manufacturer.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 400 mg/day
- Population
- Athletes
- Avg age
- 29±5.5
RCTRandomized Clinical Trial on the Use of PHYSTA Freeze-Dried Water Extract of Eurycoma longifolia for the Improvement of Quality of Life and Sexual Well-Being in Men2012n=109
A 12-wk manufacturer-funded study was conducted with 109 men aged 30-55 given 300 mg tongkat ali daily. There was a notable improvement in semen volume (+18.2%) and libido (+14%) at the end of 12 weeks. Greater improvements were seen in those with lower baseline levels, and reductions in fat mass were found in those with BMI above 25 but the study was funded by Biotropics – a tongkat ali manufacturer.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 30–55 g/day
- Population
- Men
- Participants
- 109
- Ages
- 30–55
Effects of Eurycoma longifolia Jack Supplementation on Recreational Athletes’ Endurance Running Capacity and Physiological Responses in the Heat2010
A study of recreational athletes found that Eurycoma longifolia supplementation did not significantly improve endurance running capacity or physiological heat responses.
- Effect
- No Benefit
- Population
- Athletes
AstaxanthinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Some small studies show astaxanthin supplements can slightly improve cycling speed and endurance in trained athletes.
- But a bigger study that combined astaxanthin with vitamins C and E did not find a benefit.
- Differences may be due to how fit the athletes were or how the tests were done.
Browse 3 studies
RCTThe effect of astaxanthin supplementation on performance and fat oxidation during a 40 km cycling time trial2021
In 12 trained cyclists, astaxanthin 12 mg/day for 7 days improved 40-km time trial time 1.2% and increased fat oxidation during the final kilometer versus placebo.
- Effect
- Benefit
- Duration
- 7 days
- Dose
- 12 mg/day
- Population
- Athletes
RCTAstaxanthin supplementation does not augment fat use or improve endurance performance2013
In 32 trained cyclists over 4 weeks, astaxanthin 20 mg/day with vitamins C and E did not improve fat oxidation, VO2, or time-trial performance versus placebo.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 20 mg/day
- Population
- Athletes
- Avg age
- 25±1
RCTEffect of astaxanthin on cycling time trial performance2011n=7
In 21 cyclists over 28 days, astaxanthin 4 mg/day improved 20-km time trial time by ~121 seconds versus placebo in completers, though mechanism remained unclear.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 4 mg/day
- Population
- Athletes
- Participants
- 7
Green TeaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Research on green tea’s effects on athletic performance is unclear.
- Some studies show no benefit on breathing or exercise capacity when drinking green tea extract.
- Other studies found that taking green tea pills with a key ingredient (EGCG) improved how much oxygen the body uses during exercise but didn’t improve other performance measures.
- Taking green tea supplements before exercise may help with oxygen use, but more research is needed to know if it helps with exercise results or endurance.
Browse 4 studies
Effects of Short-Term Green Tea Extract Supplementation on VO2 Max and Inflammatory and Antioxidant Responses of Healthy Young Men in a Hot Environment2020
A study of short-term green tea extract supplementation found no significant improvement in VO2 max or inflammatory markers versus placebo in trained adults.
- Effect
- No Benefit
- Population
- Adults
RCTEffect of endurance training supplemented with green tea extract on substrate metabolism during exercise in humans2010
In a 10-week training study, green tea extract 572.8 mg/day combined with endurance exercise increased fat oxidation during exercise versus training with placebo.
- Effect
- Benefit
- Duration
- 10 weeks
- Dose
- 572.8 mg/day
- Population
- Men
Controlled trialNo effects of three-week consumption of a green tea extract on time trial performance in endurance-trained men2010
In a crossover study of 9 endurance athletes, 3 weeks of green tea extract 159 mg/day catechins did not improve cycling time-trial performance versus placebo.
- Effect
- No Benefit
- Dose
- 159 mg/day
- Population
- Athletes
RCTEpigallocatechin-3-gallate increases maximal oxygen uptake in adult humans2009n=11
In a crossover RCT of 19 healthy adults, short-term EGCG 135 mg/day increased maximal oxygen uptake (VO2max) versus placebo.
- Effect
- Benefit
- Dose
- 135 mg/day
- Population
- Healthy adults
- Participants
- 11
- Avg age
- 26±2
AcaiView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Eating açaí daily may protect against exercise stress and lower fatigue markers though it won't boost your absolute maximum performance.
Browse 1 study
RCTAçai pulp supplementation as a nutritional strategy to prevent oxidative damage, improve oxidative status, and modulate blood lactate of male cyclists2020n=10
A crossover RCT in 10 male cyclists (avg age 33 years) found that 400 g/day pasteurized acai pulp for 15 days reduced blood lactate during exercise by 29% and raised anaerobic threshold versus placebo.
- Effect
- Benefit
- Duration
- 15 days
- Dose
- 400 g/day
- Population
- Athletes
- Participants
- 10
- Avg age
- 33±5
Casein ProteinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Studies on casein protein and sports performance show mixed results.
- Some research finds that casein, alone or combined with whey and other supplements, does not improve strength or body composition in certain groups like young men or women with obesity.
- Other studies suggest casein may support strength and performance in athletes and active individuals, such as basketball players, soccer players, and women starting out with exercise.
- Whey appears to produce a more reliable benefit for athletic performance compared to casein supplementation.
Browse 12 studies
RCTPre-sleep protein supplementation after an acute bout of evening resistance exercise does not improve next day performance or recovery in resistance trained men2022n=10
In 18 resistance-trained men, 40 g pre-sleep casein after evening training did not improve next-day performance or recovery vs placebo over 2 days.
- Effect
- No Benefit
- Duration
- 2 days
- Dose
- 40 g/day
- Population
- Pregnant women
- Participants
- 10
- Avg age
- 24±4
RCTPre-Sleep Consumption of Casein and Whey Protein: Effects on Morning Metabolism and Resistance Exercise Performance in Active Women2018
In 9 active women, 48 g pre-sleep casein likely raised next-morning resting metabolic rate ~4% vs placebo; 24 g casein or whey did not clearly affect exercise volume.
- Effect
- No Benefit
- Duration
- 12 months
- Dose
- 24 g
- Population
- Women
- Avg age
- 25±6.4
RCTEffects of milk proteins and combined exercise training on aortic hemodynamics and arterial stiffness in young obese women with high blood pressure2013n=11
In 33 obese hypertensive women over 4 weeks, whey or casein plus exercise lowered brachial/aortic BP and arterial stiffness vs carbohydrate control.
- Effect
- Benefit
- Duration
- 4 weeks
- Population
- Women
- Participants
- 11
- Avg age
- 30±1
Systematic reviewThe Effects of Pre- and Post-Exercise Whey vs. Casein Protein Consumption on Body Composition and Performance Measures in Collegiate Female Athletes2013n=8
In 16 collegiate female athletes over 8 weeks, 24 g whey or casein pre/post training produced similar strength and body-composition changes with resistance exercise.
- Effect
- No Benefit
- Duration
- 8 weeks
- Dose
- 48 g/day
- Population
- Female athletes
- Participants
- 8
- Avg age
- ~20
RCTThe effects of six weeks of supplementation with multi-ingredient performance supplements and resistance training on anabolic hormones, body composition, strength, and power in resistance-trained men2012n=13
In 24 resistance-trained men over 6 weeks, a multi-ingredient whey/casein supplement increased lean mass and strength markers vs placebo with periodized training.
- Effect
- Benefit
- Duration
- 6 weeks
- Population
- Pregnant women
- Participants
- 13
- Avg age
- ~24
Physiological and physical effects of different milk protein supplements in elite soccer players2011n=54
In 24 elite soccer players over 8 weeks, 1 g/kg/day whey, hydrolyzed whey, or casein with training maintained muscle mass; casein increased muscle mass slightly.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 1 g/kg/day
- Population
- Athletes
- Participants
- 54
- Avg age
- 19±1.4
RCTStimulation of muscle protein synthesis by whey and caseinate ingestion after resistance exercise in elderly individuals2011
In elderly adults after resistance exercise, whey and casein (before or after) produced similar muscle protein synthesis rates; timing did not significantly differ.
- Effect
- No Benefit
- Population
- Adults
- Avg age
- ~68
RCTEffect of protein-supplement timing on strength, power, and body-composition changes in resistance-trained men2009n=13
In 33 resistance-trained men over 10 weeks, protein timing around workouts did not outperform morning/evening supplementation for strength, power, or body composition.
- Effect
- No Benefit
- Duration
- 10 weeks
- Population
- Athletes
- Participants
- 13
Controlled trialTime-divided ingestion pattern of casein-based protein supplement stimulates an increase in fat-free body mass during resistance training in young untrained men2009n=13
In 13 untrained men over 8 weeks, time-divided casein dosing increased fat-free mass more than pre-workout-only casein during resistance training.
- Effect
- Benefit
- Dose
- 70 g/day
- Population
- Pregnant women
- Participants
- 13
- Ages
- 18–19
RCTEffects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strength2006
In 19 untrained men over 10 weeks, 20 g whey/casein protein before and after training increased lean mass, strength, and anabolic markers vs dextrose placebo.
- Effect
- Benefit
- Duration
- 10 weeks
- Dose
- 40 g/day
- Population
- Pregnant women
RCTThe effect of whey isolate and resistance training on strength, body composition, and plasma glutamine2006
In 13 male bodybuilders over 10 weeks, whey isolate produced greater lean-mass gain (5.0 vs 0.8 kg) than casein with identical resistance training.
- Effect
- No Benefit
- Duration
- 10 weeks
- Dose
- 1.5 g/kg
- Population
- Pregnant women
RCTCreatine-dextrose and protein-dextrose induce similar strength gains during training2001n=11
In 19 untrained men over 8 weeks, post-exercise casein plus glucose matched creatine plus glucose for gains in strength, muscle area, and fat-free mass.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 10 g/day
- Population
- Men
- Participants
- 11
Coenzyme Q10View supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Some studies show that exercise can reduce the body’s natural coenzyme Q10 levels, but taking supplements doesn’t appear to improve athletic performance.
- Research shows that coenzyme Q10 does not boost aerobic or anaerobic power or make exercise feel easier.
- A few studies suggest it might slightly increase tolerance for harder exercise, but results are uncertain.
- In one study, taking 300 mg of coenzyme Q10 daily for 8 days helped reduce exercise-related fatigue, while lower doses of 100–200 mg did not.
- Using 200 mg of the ubiquinol form every day for a month prevented exercise-related drops in coenzyme Q10 and reduced certain stress markers in the blood of young male athletes, though it didn’t improve performance or reduce muscle damage.
Browse 12 studies
Systematic reviewCoenzyme Q10 Supplementation in Athletes: A Systematic Review2023
A systematic review of 16 studies in athletes aged 17+ found oral CoQ10 (30–300 mg/day) increased anaerobic performance and reduced oxidative stress and liver damage markers.
- Effect
- Benefit
- Dose
- 30–300 mg/day
- Population
- Athletes
- Avg age
- ~17
RCTUbiquinol Short-Term Supplementation Prior to Strenuous Exercise Improves Physical Performance and Diminishes Muscle Damage2023n=50
A 2-week study of 100 healthy and well-trained men who were not elite athletes (firemen) found 200 mg/day ubiquinol increased maximum speed power (vertical movement of bar/time [cm/s] in the bench press but not maximum force or peak power. Coenzyme Q10 supplementation trended towards increased average load and repetitions and a decrease in perceived exertion.
- Effect
- Benefit
- Duration
- 2 weeks
- Dose
- 200 mg/day
- Population
- Athletes
- Participants
- 50
RCTEffect of ubiquinol supplementation on biochemical and oxidative stress indexes after intense exercise in young athletes2018n=21
In 21 young athletes, 200 mg/day ubiquinol for 1 month prevented exercise-induced CoQ depletion and raised antioxidant levels but did not improve performance or muscular damage markers.
- Effect
- No Benefit
- Duration
- 1 month
- Dose
- 200 mg/day
- Population
- Athletes
- Participants
- 21
- Ages
- 18–65
RCTUbiquinol supplementation enhances peak power production in trained athletes: a double-blind, placebo controlled study2013
In 100 elite trained athletes, 300 mg/day ubiquinol for 6 weeks increased peak power output by 0.08 W/kg more than placebo (P<0.03), on top of training gains.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 300 mg/day
- Population
- Athletes
- Avg age
- ~20
RCTImpact of coenzyme Q-10 on parameters of cardiorespiratory fitness and muscle performance in older athletes taking statins2012
In 20 statin-using athletes aged 50+, 200 mg/day CoQ10 for 6 weeks improved time to anaerobic threshold and leg extension reps versus placebo, but did not significantly raise anaerobic threshold itself.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 200 mg/day
- Population
- Athletes
- Ages
- 50+
RCTImpact of oral ubiquinol on blood oxidative stress and exercise performance2012n=10
In 15 exercise-trained adults, 300 mg/day ubiquinol for 4 weeks raised total blood CoQ10 by 138% but did not improve treadmill or cycle sprint performance or oxidative stress markers.
- Effect
- No Benefit
- Dose
- 300 mg/day
- Population
- Healthy adults
- Participants
- 10
- Ages
- 30–65
RCTThe effects of coenzyme Q10 supplementation on performance during repeated bouts of supramaximal exercise in sedentary men2010
In 15 sedentary men, 100 mg/day CoQ10 for 8 weeks increased mean power only during the fifth of five Wingate sprints and did not clearly outperform placebo on peak power or fatigue index.
- Effect
- No Benefit
- Duration
- 8 weeks
- Dose
- 100 mg/day
- Population
- Adults
RCTAntifatigue effects of coenzyme Q10 during physical fatigue2008n=17
In 17 healthy volunteers, 300 mg/day CoQ10 for 8 days reduced subjective fatigue and improved maximum cycling velocity during prolonged workload trials versus placebo.
- Effect
- Benefit
- Duration
- 8 days
- Dose
- 100–300 mg/day
- Population
- Healthy adults
- Participants
- 17
RCTEffect of ubidecarenone oral treatment on aerobic power in middle-aged trained subjects2000n=23
In 23 male cyclists, 8 weeks of CoQ10 supplementation did not improve peak oxygen uptake or anaerobic threshold, though exhaustion occurred at slightly higher workloads.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 23
RCTDoes exogenous coenzyme Q10 affect aerobic capacity in endurance athletes?1997
In 18 male cyclists and triathletes, 1 mg/kg/day CoQ10 for 28 days raised plasma CoQ10 but did not affect oxygen uptake, lactate kinetics, heart rate, or blood pressure during graded cycling.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 1 mg/kg
- Population
- Athletes
Controlled trialEffects of ubiquinone-10 supplementation and high intensity training on physical performance in humans1997n=9
A 22-day study including 18 healthy male subjects (20-34 years old) found that coenzyme Q10 (2 x 60 mg/day ubiquinone Marinyl) was inferior to placebo for improving the average of mean power output (4.9% placebo and 1.7% Q10, P = 0.001) and total work performed (P < 0.001) during 7 sessions of anaerobic cycling training (15 x 10 s). There were no differences between groups in the rate of perceived exertion, respiratory quotient, blood lactate concentration or heart rate during sub maximal and maximal cycling. Ubiquinone did not significantly improve running performance at submaximal or peak VO2 compared to placebo.
- Effect
- No Benefit
- Duration
- 22 days
- Dose
- 60 mg/day
- Population
- Men
- Participants
- 9
- Ages
- 20–34
RCTUbiquinone supplementation and exercise capacity in trained young and older men1995
In 19 trained men, 120 mg/day ubiquinone for 6 weeks shortened time to exhaustion versus placebo in both younger and older subjects and was ineffective as an ergogenic aid.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 120 mg/day
- Population
- Patients with heart failure
- Ages
- 22–38
Garcinia CambogiaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if garcinia, specifically its active ingredient hydroxycitric acid (HCA), improves athletic performance.
- In two small studies, people who took 250 mg of HCA daily for 5 days were able to exercise longer before getting tired and appeared to burn more fat during exercise than those taking a placebo.
Browse 2 studies
RCT(-)-Hydroxycitric acid ingestion increases fat utilization during exercise in untrained women2003
In untrained women, 250 mg/day hydroxycitric acid (HCA) for 5 days tended to lower respiratory exchange ratio and increase fat oxidation during submaximal cycling versus placebo.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 250 mg/day
- Population
- Female athletes
RCTShort-term (-)-hydroxycitrate ingestion increases fat oxidation during exercise in athletes2002
In athletes given 250 mg/day HCA for 5 days, fat oxidation increased and carbohydrate oxidation decreased during exercise at 60–80% VO2max versus placebo.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 250 mg/day
- Population
- Athletes
L-TryptophanView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Some studies show that taking L-tryptophan (about 300 mg twice a day) before exercise can boost power output in the final part of exercise by around 5% without making you feel more tired.
- However, other research found that higher doses taken during exercise did not improve endurance in trained athletes.
- L-tryptophan may help some aspects of athletic performance but not all.
Browse 2 studies
RCTL-tryptophan supplementation can decrease fatigue perception during an aerobic exercise with supramaximal intercalated anaerobic bouts in young healthy men2010
In sportsmen performing aerobic exercise with supramaximal intervals, L-tryptophan supplementation reduced fatigue perception during exercise versus placebo.
- Effect
- Benefit
- Population
- Men
- Avg age
- ~21
RCTIngestion of branched-chain amino acids and tryptophan during sustained exercise in man: failure to affect performance1995
An RCT of 10 endurance-trained men found sucrose drinks with tryptophan or BCAA during 70–75% VO2max cycling for ~122 min did not alter time to exhaustion or fatigue mechanisms.
- Effect
- No Benefit
- Dose
- 3 g/day
- Population
- Athletes
MacaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- A small study in male elite athletes suggests that taking maca (2500 mg twice daily for 8 weeks) might improve strength, power, and agility.
- However, because the study lacked a control group and did not track factors like diet, the results should be interpreted cautiously.
Browse 1 study
RCTEffect of Black Maca Supplementation on Inflammatory Markers and Physical Fitness in Male Elite Athletes2023n=16
An 8-week RCT of 44 elite athletes found black maca extract (5,000 mg/day) reduced inflammatory markers and improved aerobic performance measures vs baseline.
- Effect
- Benefit
- Dose
- 5000 mg/day
- Population
- Athletes
- Participants
- 16
Nicotinamide RibosideView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear whether nicotinamide riboside helps improve athletic performance in healthy adults.
- In one small study of young men, taking 500 mg of nicotinamide riboside two hours before exercise did not make a difference in strength, fatigue, or oxygen use compared with a placebo.
Browse 1 study
RCTAcute nicotinamide riboside supplementation improves redox homeostasis and exercise performance in old individuals: a double-blind cross-over study2020
In old but not young adults, acute nicotinamide riboside supplementation improved redox markers and isometric muscle torque by 8% and fatigue index by 15% in a crossover trial.
- Effect
- Benefit
- Population
- Older adults
Panax GinsengView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Panax ginseng generally does not improve how well people perform in sports or exercise.
- Taking it in normal or high doses for days or weeks does not help with endurance or running speed.
- Some people might feel a little less tired during exercise, but overall it doesn’t boost performance.
Browse 15 studies·1 meta-analysis
RCTShort-Term Panax Ginseng Extract Supplementation Reduces Fasting Blood Triacylglycerides and Oxygen Consumption during Sub-Maximal Aerobic Exercise in Male Recreational Athletes2024n=31
A 14-day RCT in male athletes found 500 mg/day Panax ginseng extract reduced fasting triacylglycerides without improving aerobic performance versus baseline.
- Effect
- No Benefit
- Duration
- 2 weeks
- Dose
- 500 mg/day
- Population
- Athletes
- Participants
- 31
- Ages
- 18+
MetaDose-response and temporal ergogenic effects of ginseng supplementation in athletes and active participants: A systematic review and meta-analysis2022n=14
A meta-analysis of 14 athlete trials found high-dose ginseng had a short-term vertical jump benefit but no consistent effects on perceived exertion, VO2 max, or power output.
- Effect
- Benefit
- Dose
- 300 mg/day
- Population
- Athletes
- Participants
- 14
RCTPanax ginseng Supplementation Increases Muscle Recruitment, Attenuates Perceived Effort, and Accelerates Muscle Force Recovery After an Eccentric-Based Exercise in Athletes2022
In 10 male athletes, 8 days of Panax ginseng increased muscle recruitment and reduced perceived effort during eccentric exercise versus placebo.
- Effect
- Benefit
- Duration
- 8 days
- Population
- Athletes
The effect of ginseng supplementation on anabolic index, muscle strength, body composition, and testosterone and cortisol response to acute resistance exercise in male bodybuilders2021
A study examined ginseng supplementation on anabolic index, muscle strength, and body composition, but no abstract was available in the batch record.
- Population
- Male weightlifters
RCTEffects of acute supplementation of Panax ginseng on endurance running in a hot & humid environment2011
In 9 heat-adapted runners, acute 200 mg Panax ginseng before treadmill exercise in hot humid conditions did not improve endurance performance versus placebo.
- Effect
- No Benefit
- Dose
- 200 mg/day
- Population
- Athletes
- Avg age
- 25.4±6.9
RCTGinseng supplementation does not change lactate threshold and physical performances in physically active Thai men2007n=30
An 8-week RCT in 60 young Thai navy men found 3 g/day ginseng did not change lactate threshold or aerobic performance versus placebo.
- Effect
- No Benefit
- Duration
- 8 weeks
- Dose
- 3 g/day
- Population
- Physically active men
- Participants
- 30
- Ages
- 17–22
RCTEffects of ginseng on secretory IgA, performance, and recovery from interval exercise2003n=27
An 8-week RCT in active adults found 400 mg/day ginseng G115 did not improve secretory IgA, Wingate sprint performance, or recovery versus placebo.
- Effect
- No Benefit
- Duration
- 8 weeks
- Dose
- 400 mg/day
- Population
- Healthy adults
- Participants
- 27
RCTEffects of ginseng supplementation on supramaximal exercise performance and short-term recovery2001n=12
An 8-week RCT in 24 active women found 400 mg/day Panax ginseng G115 did not improve 30-second Wingate performance or short-term recovery versus placebo.
- Effect
- No Benefit
- Duration
- 8 weeks
- Dose
- 400 mg/day
- Population
- Women
- Participants
- 12
MetaThe efficacy of ginseng. A systematic review of randomised clinical trials1999
A systematic review of 16 ginseng RCTs found inconsistent evidence for physical performance, psychomotor function, and other claimed benefits.
- Effect
- Benefit
- Dose
- 16 g/day
RCTGinseng supplementation does not enhance healthy young adults' peak aerobic exercise performance1998
A 3-week RCT in 28 healthy adults found 200 mg/day Panax ginseng did not improve peak aerobic exercise performance, VO2, or lactate at exhaustion versus placebo.
- Effect
- No Benefit
- Duration
- 3 weeks
- Dose
- 200 mg/day
- Population
- Healthy adults
- Avg age
- 23.2±3.2
The effect of ginseng supplementation on strength development in response to resistance exercise training1998
A study evaluated ginseng supplementation on strength gains with resistance exercise, but no abstract was available in the batch record.
RCTNo ergogenic effects of ginseng (Panax ginseng C.A. Meyer) during graded maximal aerobic exercise1997
An 8-week RCT in 36 men found 200–400 mg/day Panax ginseng G115 did not alter submaximal or maximal aerobic exercise responses versus placebo.
- Effect
- No Benefit
- Duration
- 8 weeks
- Dose
- 400 mg/day
- Population
- Men
Failure of chronic ginseng supplementation to affect work performance and energy metabolism in healthy adult females1996
A chronic ginseng supplementation study found no effect on work performance or energy metabolism, but no abstract was available in the batch record.
- Effect
- No Benefit
- Population
- Women
Controlled trialNo ergogenic effect of ginseng ingestion1996
In healthy men, 7 days of Panax ginseng extract 8–16 mg/kg before cycling did not improve VO2, lactate, or time to exhaustion versus placebo in a crossover trial.
- Effect
- No Benefit
- Duration
- 7 days
- Dose
- 16 mg/kg
- Population
- Men
Effects of Standardized Ginseng Extract and Exercise Training on Aerobic and Anaerobic Exercise Capacities in Humans1995
A trial of standardized ginseng extract plus exercise training on aerobic and anaerobic capacity lacked an abstract in the batch record.
- Effect
- No Benefit
ReishiView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- A small study showed that taking 1000 mg of reishi mushroom daily for 30 days helped improve heart rate, oxygen use, and physical work ability in sedentary young adults.
- It is still unclear if reishi improves athletic performance overall.
Browse 1 study
RCTEfficacy of Lingzhi or Reishi Medicinal Mushroom Ganoderma lucidum (Agaricomycetes) Supplementation on Psychological Stress and Selective Fitness Profile Parameters in Female College Students in West Bengal, India2024n=26
In 26 sedentary female college students over 30 days, Ganoderma lucidum 500–1000 mg/day improved select fitness and psychophysiological parameters versus placebo.
- Effect
- Benefit
- Duration
- 30 days
- Dose
- 1000 mg/day
- Population
- Women
- Participants
- 26
- Avg age
- ~21
TheanineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- L-theanine has no meaningful benefit for Athletic performance.
Browse 1 study
RCTThe effect of L-theanine supplementation on the immune system of athletes exposed to strenuous physical exercise2019n=10
A randomized controlled study showing that L-theanine supplementation supported aspects of immune function in athletes undergoing repeated strenuous exercise. A 6-week study of 20 elite rowers found that 150 mg/day theanine contributed to significant post-exercise decreases in interleukin 10 concentration, reflected by higher interleukin 2 to IL-10 and interferon gamma to IL-10 ratios. There were no effects on lactate, time performance or white blood cell function from theanine supplementation compared to placebo.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 150 mg/day
- Population
- Athletes
- Participants
- 10
- Avg age
- ~21
Vitamin KView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- A small study found that taking vitamin K2 by mouth—320 micrograms daily for 4 weeks, then 160 micrograms daily for another 4 weeks—increased the maximum heart output (the highest volume of blood your heart can pump per minute) during exercise by 12% in trained athletes, compared to those taking a placebo.
Browse 1 study
RCTOral Consumption of Vitamin K2 for 8 Weeks Associated With Increased Maximal Cardiac Output During Exercise2017n=26
In an RCT of 26 participants, 300 mg/day, for 8 weeks, results • Vitamin K2 supplementation was associated with a 12% increase in maximal cardiac output, with P = .031, with a trend toward an increase in heart-rate AUC, with P = .070.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 300 mg/day
- Population
- Female athletes
- Participants
- 26
YohimbeView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if yohimbine helps improve athletic performance.
- In soccer players, taking 20 mg daily for 3 weeks did not increase muscle or exercise ability.
- But in active women, a single low dose taken before sprinting increased power and reduced fatigue during the test.
- More research is needed to see if regular use has lasting effects.
Browse 2 studies
RCTEffects of Acute Yohimbine Hydrochloride Supplementation on Repeated Supramaximal Sprint Performance2022n=18
A crossover trial in 18 active females found that a single 2.5 mg dose of yohimbine before three Wingate sprints raised mean power, total work, and heart rate versus placebo, with lower post-exercise lactate and fatigue index.
- Effect
- Benefit
- Dose
- 2.5 mg yohimbine hydrochloride
- Population
- Athletes
- Participants
- 18
RCTYohimbine: the effects on body composition and exercise performance in soccer players2006n=20
In 20 professional soccer players, 20 mg/day yohimbine for 21 days significantly reduced body fat (9.3% to 7.1%) but did not change body mass, muscle mass, or exercise performance indicators.
- Effect
- No Benefit
- Duration
- 21 days
- Dose
- 20 mg/day
- Population
- Athletes
- Participants
- 20
CocoaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Flavanols, natural compounds found in cocoa, may help protect heart health.
- In one study, 28 young male soccer players ate 105 g of milk chocolate with flavanols every day for 2 weeks.
- Compared with another type of chocolate that contained almost no flavanols, the flavanol-rich chocolate lowered blood pressure, total cholesterol, and "bad" LDL cholesterol.
- It also reduced markers of oxidative stress and slightly improved vitamin E status.
- These results suggest that chocolate with higher flavanol content may be healthier for the heart than regular milk chocolate, though the study was small and short-term.
Browse 1 study
Controlled trialRegular consumption of a flavanol-rich chocolate can improve oxidant stress in young soccer players2005n=28
In 28 young soccer players over 14 days, flavanol-rich chocolate 105 g/day lowered diastolic and mean blood pressure, LDL cholesterol, and oxidative stress markers versus cocoa-butter control.
- Effect
- Benefit
- Dose
- 105 g/day
- Population
- Athletes
- Participants
- 28
- Ages
- 18–20
EchinaceaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking echinacea does not seem to improve exercise performance or increase the body's ability to carry oxygen in the blood.
- One early study showed a small boost in certain blood markers and fitness in active men, but later studies with athletes and fit people found no benefits.
- A review of several studies concluded that echinacea does not help people exercise better or increase oxygen capacity.
- Overall, echinacea probably does not improve fitness or endurance but more studies are needed.
Browse 4 studies·1 meta-analysis
MetaEchinacea Supplementation Does Not Impact Aerobic Capacity and Erythropoiesis in Athletes: A Meta-Analysis2024n=107
A meta-analysis of 6 RCTs (107 athletes) found echinacea supplementation did not significantly improve maximal oxygen uptake, erythropoietin, hemoglobin, or hematocrit, though small positive effect sizes for hemoglobin did not reach significance.
- Effect
- No Benefit
- Population
- Athletes
- Participants
- 107
RCTSix weeks of oral Echinacea purpurea supplementation does not enhance the production of serum erythropoietin or erythropoietic status in recreationally active males with above-average aerobic fitness2019n=12
In 24 recreationally active men given 8,000 mg/day E. purpurea or placebo for 6 weeks, echinacea did not change serum erythropoietin, hemoglobin, hematocrit, or other erythropoietic markers.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 8000 mg/day
- Population
- Athletes
- Participants
- 12
- Avg age
- 25.2±1.4
RCTEchinacea-Based Dietary Supplement Does Not Increase Maximal Aerobic Capacity in Endurance-Trained Men and Women2015n=15
In 45 endurance-trained adults over 35 days, echinacea at 8,000 or 16,000 mg/day did not increase VO2max or alter blood markers compared with placebo, despite VO2max gains in the placebo and low-dose groups.
- Effect
- No Benefit
- Duration
- 35 days
- Population
- Athletes
- Participants
- 15
RCTRunning economy and maximal oxygen consumption after 4 weeks of oral Echinacea supplementation2012n=60
In 24 men given 8,000 mg/day echinacea or placebo for 4 weeks, the echinacea group had significantly higher EPO, VO2max (+1.47%), and improved running economy versus placebo.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 8000 mg/day
- Population
- Healthy adults
- Participants
- 60
- Avg age
- ~25
EleutheroView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Studies mostly show that taking eleuthero (Siberian ginseng) root does not improve exercise performance or endurance for most people.
- Some research found no changes in heart rate, stamina, or recovery after a few weeks of use.
- But in one study, taking eleuthero twice daily for 8 weeks helped improve cycling endurance.
- More research is needed to confirm these possible benefits.
Browse 7 studies
RCTThe effect of eight weeks of supplementation with Eleutherococcus senticosus on endurance capacity and metabolism in human2010
In 9 recreationally trained men over 8 weeks, 800 mg/day Eleutherococcus senticosus increased VO2 peak 12% (p < 0.05) and endurance time 23% (p < 0.05) versus placebo in crossover design.
- Effect
- Benefit
- Duration
- 8 weeks
- Dose
- 800 mg/day
- Population
- Adults
RCTThe effect of siberian ginseng (Eleutherococcus senticosus) on substrate utilization and performance2000
In 9 trained cyclists over 7 days, 1,200 mg/day Siberian ginseng did not alter substrate utilization, 10-km time trial performance, or steady-state exercise responses versus placebo.
- Effect
- No Benefit
- Duration
- 7 days
- Dose
- 200 mg/day
- Population
- Athletes
- Avg age
- ~28
RCTThe influence of active components of Eleutherococcus senticosus on cellular defence and physical fitness in man2000n=50
In 50 healthy volunteers over 30 days, Taiga Wurzel (eleuthero) improved lipid markers and oxygen plateau on ergospirometry versus echinacea control, suggesting effects on cellular defense and fitness.
- Effect
- Benefit
- Duration
- 30 days
- Population
- Healthy adults
- Participants
- 50
RCTEffect of ENDUROX on metabolic responses to submaximal exercise1999n=10
In 10 men over 7 days in crossover design, 800 mg ENDUROX did not significantly affect oxygen consumption, heart rate, lactate, or perceived exertion during submaximal or peak exercise versus placebo.
- Effect
- No Benefit
- Duration
- 7 days
- Dose
- 800 mg/day
- Population
- Men
- Participants
- 10
The effects of ENDUROX on the physiological responses to stair-stepping exercise1999
A 1999 study investigated ENDUROX effects on physiological responses during stair-stepping exercise; detailed outcome data were not available in the indexed abstract.
RCTEffect of Eleutherococcus senticosus on submaximal and maximal exercise performance1996
In 20 trained distance runners over 6 weeks, Eleutherococcus senticosus extract did not significantly change VO2, heart rate, time to exhaustion, or serum lactate during submaximal or maximal tests versus placebo.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 3.4 mL/day
- Population
- Athletes
Effect of Eleutherococcus senticosus extract on human physical working capacity1986
A 1986 study evaluated Eleutherococcus senticosus extract on human physical working capacity; detailed outcome data were not available in the indexed abstract.
GlutamineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking glutamine by mouth does not appear to boost athletic performance or help the immune system during hard or long exercise.
- Small studies in athletes and healthy adults found no difference compared to taking a placebo.
Browse 7 studies·1 meta-analysis
MetaThe effect of glutamine supplementation on athletic performance, body composition, and immune function: A systematic review and a meta-analysis of clinical trials2019
A meta-analysis of RCTs found glutamine supplementation did not significantly improve athletic performance, body composition, or VO2 max versus placebo.
- Effect
- No Benefit
- Dose
- 200 mg/kg
- Population
- Athletes
- Ages
- ≥18
RCTGlutamine and carbohydrate supplements reduce ammonemia increase during endurance field exercise2007
In a crossover study of 15 runners, glutamine plus carbohydrate before endurance exercise reduced exercise-induced hyperammonemia versus placebo or glutamine alone.
- Effect
- No Benefit
- Dose
- 1 g/kg
- Population
- Athletes
RCTEffect of glutamine supplementation combined with resistance training in young adults2001n=17
In a 6-week RCT of 31 young adults doing resistance training, glutamine 0.9 g/kg lean mass/day did not increase strength or lean mass gains versus placebo.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 0.9 g/kg/day
- Population
- Healthy adults
- Participants
- 17
- Ages
- 18–24
RCTAcute L-glutamine ingestion does not improve maximal effort exercise1998
In a crossover trial of 10 trained men, acute glutamine ingestion did not improve maximal cycling performance or alter acid-base balance versus placebo.
- Effect
- No Benefit
- Dose
- 0.03 g/kg body mass
- Population
- Healthy adults
RCTCompetitive sustained exercise in humans, lymphokine activated killer cell activity, and glutamine--an intervention study1998n=9
In an RCT of 16 marathon runners, post-race glutamine 100 mg/kg preserved plasma glutamine but did not prevent exercise-induced lymphocyte function changes versus placebo.
- Effect
- No Benefit
- Dose
- 100 mg/kg
- Population
- Athletes
- Participants
- 9
RCTEffect of glutamine supplementation on changes in the immune system induced by repeated exercise1998
In a crossover RCT of athletes, glutamine supplementation did not prevent exercise-induced declines in lymphocyte proliferation or LAK cell activity versus placebo.
- Effect
- No Benefit
- Population
- Men
Controlled trialThe effects of oral glutamine supplementation on athletes after prolonged, exhaustive exercise1997
In controlled trials of athletes and sedentary controls, oral glutamine after exhaustive exercise restored plasma glutamine but did not clearly prevent immunosuppression.
- Effect
- No Benefit
- Population
- Athletes
L-CarnitineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Hard exercise can lower levels of L‑carnitine in the blood of trained athletes.
- While supplements might help restore these levels, research results are mixed.
- Some studies have found that taking L‑carnitine (2 grams daily for several weeks or before exercise) can boost endurance, improve performance, and reduce muscle soreness, but other studies did not find clear benefits.
- Similarly, some research shows that L‑carnitine may reduce lactic acid buildup and improve energy and oxygen use during exercise, but other studies show no effect.
- Differences in study size, supplement dosing, and length of use may explain the mixed results.
Browse 22 studies
RCTThe effects of acute L-carnitine supplementation on endurance performance of athletes2014n=12
In 12 footballers, acute L-carnitine 3 g did not significantly improve endurance performance versus placebo in a randomized trial.
- Effect
- No Benefit
- Dose
- 3 g/day
- Population
- Athletes
- Participants
- 12
The effects of L-carnitine supplementation in different phases of menstrual cycle on the metabolic responses after exhausted exercise in active women2011
In active women across menstrual cycle phases, L-carnitine supplementation did not significantly alter post-exercise metabolic responses, though minor recovery marker changes were reported.
- Effect
- No Benefit
- Population
- Women
The effect of L-carnitine supplementation on 1500 m running performance2010
Acute L-carnitine before a 1500 m run did not significantly improve performance time or rating of perceived exertion versus placebo in trained runners.
- Effect
- No Benefit
RCTThe supplementation of L-carnitine does not promote alterations in the resting metabolic rate and in the use of energetic substrates in physically active individuals2010n=11
In 11 adults, L-carnitine 8 g/day for 30 days did not change resting metabolic rate or fasting free fatty acid oxidation versus baseline.
- Effect
- No Benefit
- Dose
- 8 g/day
- Population
- Adults
- Participants
- 11
- Ages
- 40–58
RCTThe effects of acute L-carnitine administration on ventilatory breakpoint and exercise performance during incremental exercise2009
Acute L-carnitine did not significantly change ventilatory threshold or VO2max during incremental cycling versus placebo in a crossover trial.
- Effect
- No Benefit
The effects of acute L-carnitine supplementation on anaerobic threshold and lactate accumulation during an incremental exercise2009
Acute L-carnitine supplementation did not significantly alter anaerobic threshold or blood lactate accumulation during incremental exercise in trained adults.
- Effect
- No Benefit
- Population
- Adults
RCTEffect of glycine propionyl-L-carnitine on aerobic and anaerobic exercise performance2008n=12
In 12 healthy adults, glycine propionyl-L-carnitine 4.5 g/day for 4 weeks plus endurance training did not significantly improve aerobic or anaerobic performance versus training alone.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 4.5 g/day
- Population
- Adults
- Participants
- 12
- Ages
- 18–44
Clinical trialEffects of acute L-carnitine intake on metabolic and blood lactate levels of elite badminton players2008
In elite badminton players, acute L-carnitine did not significantly change metabolic or blood lactate responses during match-play versus baseline.
- Effect
- No Benefit
- Dose
- 2 g/day
RCTEffects of Citric Acid and L-Carnitine on Physical Fatigue2007n=18
In 18 adults, combined citric acid and L-carnitine for 8 days reduced subjective physical fatigue versus baseline in a randomized trial.
- Effect
- No Benefit
- Duration
- 8 days
- Dose
- 700 mg/day
- Population
- Healthy adults
- Participants
- 18
RCTL-Carnitine and the recovery from exhaustive endurance exercise: a randomised, double-blind, placebo-controlled trial2005n=12
In 12 trained men, L-carnitine 2 g twice daily for 4–14 days did not accelerate recovery of performance after exhaustive endurance exercise versus placebo.
- Effect
- No Benefit
- Duration
- 4–14 days
- Dose
- 4 g/day
- Participants
- 12
RCTEffects of carnitine coingested caffeine on carnitine metabolism and endurance capacity in athletes2001
Co-ingesting caffeine with carnitine did not enhance endurance capacity or alter carnitine metabolism versus carnitine alone in a crossover exercise trial.
- Effect
- No Benefit
- Population
- Athletes
Plasma and urine carnitine concentrations in well-trained athletes at rest and after exercise. Influence of L-carnitine intake1999
In well-trained athletes at rest and after exercise, plasma and urine carnitine concentrations changed with training status but acute supplementation effects were not clinically meaningful.
- Effect
- No Benefit
- Dose
- 1 g/day
- Population
- Athletes
RCTEffects of L-carnitine supplementation on physical performance and energy metabolism of endurance-trained athletes: a double-blind crossover field study1996
In endurance athletes during a marathon, acute L-carnitine did not significantly improve performance or substrate metabolism versus placebo in a field crossover study.
- Effect
- No Benefit
- Dose
- 2 g/day
- Population
- Athletes
RCTThe effects of L-carnitine supplementation on performance during interval swimming1994
In 20 swimmers, L-carnitine 4 g/day for 7 days did not improve interval swim performance versus placebo in a double-blind trial.
- Effect
- No Benefit
- Duration
- 7 days
- Dose
- 4 g/day
Controlled trialEffect of L-carnitine on submaximal exercise metabolism after depletion of muscle glycogen1993
In trained subjects after glycogen depletion, L-carnitine did not significantly alter submaximal exercise metabolism versus placebo.
- Effect
- No Benefit
- Dose
- 3 g/day
- Population
- Athletes
Controlled trialCarnitine in muscle, serum, and urine of nonprofessional athletes: effects of physical exercise, training, and L-carnitine administration1991n=24
In 24 nonprofessional athletes, oral L-carnitine 2 g/day for 6 months raised muscle carnitine but did not significantly improve performance versus placebo.
- Effect
- No Benefit
- Duration
- 6 months
- Dose
- 2 g/day
- Population
- Athletes
- Participants
- 24
Controlled trialEffects of L-carnitine administration on VO₂max and the aerobic-anaerobic threshold in normoxia and acute hypoxia1990n=56
In 7 healthy men, L-carnitine did not significantly change VO2max, anaerobic threshold, or ventilatory responses during exercise versus placebo.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 56
RCTInfluence of L-carnitine administration on maximal physical exercise1990
A double-blind crossover trial in ten moderately trained young men receiving 2 g oral L-carnitine or placebo 1 h before exercise found that L-carnitine significantly increased both maximal oxygen uptake (VO₂max) and power output, and reduced oxygen uptake, CO₂ production and lactate at the same intensities in the supplementation trial.
- Effect
- Benefit
- Dose
- 2 g/day
- Population
- Moderately trained young men
Controlled trialDecrease in respiratory quotient during exercise following L-carnitine supplementation1989n=10
In 10 endurance-trained adults, L-carnitine 2 g/day reduced respiratory quotient during submaximal exercise, suggesting greater fat oxidation versus baseline.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 2 g/day
- Population
- Athletes
- Participants
- 10
Controlled trialStudies concerning some acute biological changes after endovenous administration of 1 g L-carnitine, in elite athletes1987
In 17 elite swimmers, IV L-carnitine 1 g acutely did not significantly improve performance biomarkers versus placebo in a double-blind crossover trial.
- Effect
- No Benefit
- Dose
- 1 g/day
- Population
- Athletes
Controlled trialThe effect of oral supplementation with L-carnitine on maximum and submaximum exercise capacity1987
A randomized controlled trial in healthy, untrained subjects receiving 2 g/day oral L-carnitine for 2–4 weeks found no significant improvements in maximum oxygen uptake or heart rate and only minor changes in submaximal exercise heart rates, concluding limited performance benefit.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 2 g/day
CrossoverEffects of L-carnitine loading on the aerobic and anaerobic performance of endurance athletes1985
In endurance athletes, L-carnitine loading did not significantly improve aerobic or anaerobic performance versus placebo in a crossover trial.
- Effect
- No Benefit
- Duration
- 2 weeks
- Dose
- 4 g/day
- Population
- Athletes
MagnesiumView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking magnesium supplements by mouth does not seem to help increase energy or improve endurance when exercising.
- Different types of magnesium, like magnesium oxide or aspartate, have not been shown to boost athletic performance, whether taken alone or with other nutrients.
Browse 7 studies
RCTEffects of Supplementing Zinc Magnesium Aspartate on Sleep Quality and Submaximal Weightlifting Performance, following Two Consecutive Nights of Partial Sleep Deprivation2024n=12
A double-blind crossover RCT of 16 sleep-deprived trained males found ZMA supplementation for two nights had no significant effect on sleep quality or next-morning grip strength, bench press, or back squat performance.
- Effect
- No Benefit
- Participants
- 12
MetaThe effects of magnesium supplementation on exercise performance2000n=12
A review of 12 magnesium supplementation exercise studies found no consistent ergogenic effect on strength, anaerobic, or aerobic performance regardless of dose or duration.
- Effect
- No Benefit
- Dose
- 116 mg/day
- Population
- Female athletes
- Participants
- 12
RCTLack of effect of oral Mg-supplementation on Mg in serum, blood cells, and calf muscle1998n=10
A controlled supplementation study finding no significant changes in serum, blood cell, or muscle magnesium levels following oral magnesium supplementation. A 3-wk study of athletes with low-normal serum magnesium found that 500 mg/day magnesium oxide did not increase serum magnesium concentration or improve exercise performance.
- Effect
- No Benefit
- Duration
- 3 weeks
- Dose
- 500 mg/day
- Population
- Athletes
- Participants
- 10
RCTOn the significance of magnesium in extreme physical stress1998
A double-blind RCT of 23 triathletes found 4 weeks of magnesium orotate (17 mmol/day) improved triathlon times and altered glucose/insulin responses during extreme exercise vs placebo.
- Effect
- Benefit
- Duration
- 4 weeks
Controlled trialEffects of potassium + magnesium aspartate on muscle metabolism and force development during short intensive static exercise1985
A controlled study in rats and human volunteers found potassium-magnesium aspartate did not improve muscle force, endurance, or metabolic parameters during short intensive static exercise.
- Effect
- No Benefit
Controlled trialThe effects of oral administration of salts of aspartic acid on the metabolic response to prolonged exhausting exercise in man1983n=8
A double-blind study of 8 healthy men found 6 g potassium-magnesium aspartate over 24 hours did not improve cycling endurance to exhaustion (~83 vs 85 min) or alter exercise metabolism vs placebo.
- Effect
- No Benefit
- Dose
- 6 g/day
- Population
- Men
- Participants
- 8
Controlled trialAbsence of effect of potassium-magnesium aspartate on physiologic responses to prolonged work in aerobically trained men1982n=7
A controlled trial of 7 aerobically trained men found oral potassium-magnesium aspartate (7.2 g/24 h) had no effect on cardiorespiratory, hematologic, or metabolic responses during 90 min treadmill exercise at ~62% VO2 max.
- Effect
- No Benefit
- Dose
- 7.2 g/day
- Participants
- 7
MelatoninView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Research shows melatonin does not generally boost sports performance or strength.
- Taking 6 mg before weight training, 5 mg before exercise, or 5 mg at night does not seem to help with strength, endurance, or next‑day performance.
- But in one small study of soccer players, taking 5 mg daily for six days slightly slowed down physical performance loss in activities like jumping, agility, and sprints.
Browse 6 studies
RCTMelatonin Supplementation Enhances Next-Day High-Intensity Exercise Performance and Recovery in Trained Males: A Placebo-Controlled Crossover Study2025
A crossover RCT of 12 trained males found 6 mg melatonin the night before improved next-day shuttle test distance, fatigue index, and perceived recovery up to 72 hours vs placebo.
- Effect
- Benefit
- Dose
- 6 mg/day
- Population
- ALL patients
- Avg age
- 21.92±2.84
Systematic reviewThe Effects of Melatonin Supplementation on Professional Football Player Performance: A Systematic Review2023
A systematic review of 8 studies in professional soccer players found 5–8 mg melatonin reduced oxidative stress and muscle damage markers but did not consistently improve physical performance.
- Effect
- No Benefit
- Dose
- 5–8 mg
- Population
- Athletes
RCTMelatonin supplementation alleviates cellular damage and physical performance decline induced by an intensive training period in professional soccer players2022n=10
An RCT of 20 soccer players during 6-day intensive training found daily 5 mg melatonin prevented rises in oxidative protein products and attenuated declines in jump and sprint performance vs placebo.
- Effect
- Benefit
- Dose
- 5 mg
- Population
- Athletes
- Participants
- 10
- Avg age
- 18.8±1.3
RCTConsumption of a 5-mg Melatonin Supplement Does Not Affect 32.2-km Cycling Time Trial Performance2018n=10
A crossover RCT of 10 trained cyclists found 5 mg melatonin taken before sleep did not affect next-day 32.2-km time-trial performance or power output in a thermoneutral environment.
- Effect
- No Benefit
- Dose
- 5 mg
- Population
- Men
- Participants
- 10
- Avg age
- 25.1±4
RCTEffects of resistance exercise session after oral ingestion of melatonin on physiological and performance responses of adult men2006n=10
An RCT of 10 men found 6 mg melatonin before resistance exercise lowered GH area-under-curve during and after training without impairing strength performance.
- Effect
- No Benefit
- Dose
- 6 mg
- Population
- Men
- Participants
- 10
Controlled trialAre there hangover-effects on physical performance when melatonin is ingested by athletes before nocturnal sleep?2001n=12
A double-blind crossover study of 12 athletes found 5 mg melatonin before sleep produced no meaningful hangover effects on grip strength, cycling time trial, or sleep quality the next morning.
- Effect
- No Benefit
- Dose
- 5 mg
- Population
- Athletes
- Participants
- 12
QuercetinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking quercetin alone does not improve oxygen use or endurance performance in athletes, based on several studies. Taking 500 mg twice daily for up to 4 weeks did not help soldiers or cyclists perform better or feel less tired during exercise.
- When combined with other ingredients, such as mangiferin, one dose of quercetin helped improve short exercise performance and made it feel easier, but it did not help other measures like heart rate or muscle soreness. Taking quercetin with L-citrulline did not improve cycling performance.
Browse 6 studies
RCTEffects of a Singular Dose of Mangiferin-Quercetin Supplementation on Basketball Performance: A Double-Blind Crossover Study of High-Level Male Players2024n=38
In 38 basketball players, pre-exercise mangiferin-quercetin (84/140 mg) shortened circuit time and lowered perceived exertion during a simulation test versus placebo.
- Effect
- Benefit
- Dose
- 84 mg mangiferin + 140 mg quercetin
- Population
- Women with PMS
- Participants
- 38
- Ages
- 18+
RCTThe effect of quercetin and citrulline on cycling time trial performance2024
In cyclists, 28 days of quercetin plus citrulline supplementation did not significantly improve time-trial performance versus placebo.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 500 mg
- Population
- Athletes
RCTEffects of short-term quercetin supplementation on soldier performance2012
In soldiers, quercetin 1000 mg/day for 8.5 days did not improve VO2peak, loaded march performance, or cycling time trial versus placebo.
- Effect
- No Benefit
- Duration
- 8.5 days
- Dose
- 1000 mg/day
RCTEffect of quercetin supplementation on repeated-sprint performance, xanthine oxidase activity, and inflammation2011n=15
In 15 men, quercetin 1000 mg/day for 1 week did not improve repeated-sprint performance and increased fatigue decrement versus carbohydrate placebo.
- Effect
- No Benefit
- Duration
- 1 week
- Dose
- 1000 mg/day
- Population
- Young adults
- Participants
- 15
Controlled trialThermotolerance and heat acclimation may share a common mechanism in humans2011n=8
In 8 men, quercetin 2000 mg/day blocked heat-acclimation benefits on GI permeability and cytokines during exercise-heat stress versus placebo.
- Effect
- No Benefit
- Dose
- 2000 mg/day
- Population
- Men
- Participants
- 8
RCTNo effect of nutritional adenosine receptor antagonists on exercise performance in the heat2008n=10
In 10 men exercising in heat, caffeine 9 mg/kg but not quercetin 2000 mg improved endurance performance; neither matched in vitro adenosine receptor inhibition levels affected outcomes.
- Effect
- No Benefit
- Dose
- 9 mg/kg
- Population
- Men
- Participants
- 10
TyrosineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking tyrosine before exercise doesn’t make you stronger or improve your workout performance.
- Research shows it doesn’t boost strength, endurance, or results during treadmill or cycling sessions, even in hot conditions.
- A small study also found that adding tyrosine to a pre-workout drink offered no benefit beyond caffeine alone.
Browse 11 studies
RCTAcute effects of multi-ingredient pre-workout dietary supplement on anaerobic performance in untrained men: a randomized, crossover, single blind study2024
A crossover RCT of 12 untrained men found that a multi-ingredient pre-workout with tyrosine significantly improved peak and mean power in the Wingate anaerobic test versus placebo.
- Effect
- Benefit
- Population
- Men
- Avg age
- ~22
Clinical trialEffects of Multi-Ingredient Pre-Workout Supplement and Caffeine on Bench Press Performance: A Single-Blind Cross-Over Study2022n=15
In 15 resistance-trained men, anhydrous caffeine alone produced greater bench press repetition volume than a multi-ingredient pre-workout supplement containing caffeine, with no differences in perceived exertion or arousal.
- Effect
- No Benefit
- Dose
- 6 mg/kg
- Population
- Women
- Participants
- 15
- Avg age
- 5.6±3.38
RCTNo Influence of Low-, Medium-, or High-Dose Tyrosine on Exercise in a Warm Environment2020
An RCT of 8 men found that 150–400 mg/kg tyrosine did not improve cycling time trial performance in a warm environment despite increased plasma tyrosine ratios.
- Effect
- No Benefit
- Dose
- 150–400 mg/day
- Avg age
- ~23
Effects of tyrosine supplementation ration on anaerobic sports capacity and plasma catecholamine levels in soccer athletes2017
A study of soccer athletes found that tyrosine supplementation increased anaerobic sports capacity and elevated plasma catecholamine levels.
- Population
- Athletes
RCTEffect of tyrosine ingestion on cognitive and physical performance utilising an intermittent soccer performance test (iSPT) in a warm environment2014
An RCT of 8 soccer players found that 150 mg/kg tyrosine improved vigilance during intermittent exercise in heat but did not improve total distance covered.
- Effect
- No Benefit
- Dose
- 150 mg/kg
- Population
- Athletes
RCTFailure of oral tyrosine supplementation to improve exercise performance in the heat2014
An RCT of 7 endurance-trained men found that 150 mg/kg tyrosine did not improve self-paced cycling time trial performance in 30°C heat versus placebo.
- Effect
- No Benefit
- Dose
- 150 mg/kg
RCTOral tyrosine supplementation improves exercise capacity in the heat2011
An RCT of 8 men found that 150 mg/kg tyrosine significantly extended cycling endurance in heat (80.3 vs 69.2 min) and reduced perceived exertion versus placebo.
- Effect
- Benefit
- Dose
- 150 mg/kg
- Population
- Men
- Avg age
- ~32
Controlled trialDietary tyrosine benefits cognitive and psychomotor performance during body cooling2006n=15
A controlled study of 15 subjects found that 300 mg/kg tyrosine preserved working memory and marksmanship performance during cold water immersion versus placebo.
- Effect
- Benefit
- Dose
- 300 mg/kg
- Participants
- 15
RCTIngestion of tyrosine: effects on endurance, muscle strength, and anaerobic performance2005n=20
An RCT of 20 men found that 150 mg/kg tyrosine had no significant effect on treadmill endurance, handgrip strength, or stair-stepping anaerobic power versus placebo.
- Effect
- No Benefit
- Dose
- 150 mg/kg
- Population
- Men
- Participants
- 20
RCTEffects of L-tyrosine and carbohydrate ingestion on endurance exercise performance2002
An RCT of 9 cyclists found that 25 mg/kg L-tyrosine did not improve time trial performance after 90 min of steady-state cycling; carbohydrate improved performance but tyrosine did not.
- Effect
- No Benefit
- Dose
- 25 mg/kg
- Population
- Athletes
Controlled trialInfluence of paroxetine, branched-chain amino acids and tyrosine on neuroendocrine system responses and fatigue in humans1998n=10
A controlled study of 10 men found that 20 g tyrosine altered neuroendocrine responses during exercise but did not improve endurance performance; BCAA improved post-exercise drive on psychometric tests.
- Effect
- No Benefit
- Dose
- 21 g BCAA
- Population
- Men
- Participants
- 10
Vitamin DView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking vitamin D by mouth does not appear to improve athletic performance.
- Studies in athletes and active young men show that different doses of vitamin D, taken weekly or daily for several weeks, did not help with strength, sprinting, jumping, or aerobic fitness compared to a placebo.
- This means vitamin D supplements are unlikely to boost sports performance in healthy people.
Browse 5 studies
RCTVitamin D Supplementation Has No Impact on Cardiorespiratory Fitness, but Improves Inflammatory Status in Vitamin D Deficient Young Men Engaged in Resistance Training2022n=39
In 39 vitamin D–deficient young men given 8000 IU/day for 12 weeks during resistance training, vitamin D improved inflammatory status but did not increase VO2max.
- Effect
- No Benefit
- Duration
- 12 weeks
- Dose
- 8000 IU/day
- Population
- Men
- Participants
- 39
RCTVitamin D₃ Supplementation Does Not Improve Sprint Performance in Professional Rugby Players: A Randomized, Placebo-Controlled, Double-Blind Intervention Study2018n=57
In 57 professional rugby players given ~3570 IU/day for 11–12 weeks, vitamin D raised serum 25(OH)D but did not improve sprint or most physical performance measures.
- Effect
- No Benefit
- Duration
- 11–12 weeks
- Dose
- 3570 IU/day
- Population
- Athletes
- Participants
- 57
RCTA systems-based investigation into vitamin D and skeletal muscle repair, regeneration, and hypertrophy2015n=20
In 20 men with low 25(OH)D given 4000 IU/day for 6 weeks, vitamin D improved peak torque recovery at 48 h and 7 days after damaging eccentric exercise.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 4000 IU/day
- Population
- Men
- Participants
- 20
RCTThe effects of vitamin D₃ supplementation on serum total 25[OH]D concentration and physical performance: a randomised dose-response study2013
In 30 club athletes given 20,000 or 40,000 IU/week for 12 weeks, vitamin D raised serum 25(OH)D above 50 nmol/L but did not improve bench press, leg press, or vertical jump.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 20,000–40,000 IU/week vitamin D3
- Population
- Athletes
RCTDifferent doses of supplemental vitamin D maintain interleukin-5 without altering skeletal muscle strength: a randomized, double-blind, placebo-controlled study in vitamin D sufficient adults2012n=15
In 30 young vitamin D–sufficient adults given 200 or 4000 IU/day for 28 days, supplementation maintained 25(OH)D and IL-5 but did not change leg muscle strength.
- Effect
- No Benefit
- Duration
- 1 year
- Dose
- 4000 IU/day
- Population
- Young adults
- Participants
- 15
- Ages
- 18–45
CholineView supplement →
Do not purchase·★★★★★
How we scored this▸
- Taking choline supplements before exercise does not help improve athletic performance or delay tiredness.
- Studies show that both athletes and non-athletes do not get stronger, faster, or have improved endurance after taking choline compared to a placebo.
Browse 3 studies
RCTCholine ingestion does not modify physical or cognitive performance2002n=13
In 13 men, 50 mg/kg choline raised plasma choline during exercise but did not improve physical performance, reaction time, reasoning, vigilance, spatial memory, or working memory after exhaustive load carriage.
- Effect
- No Benefit
- Dose
- 50 mg/kg
- Population
- Men
- Participants
- 13
- Avg age
- ~28
Controlled trialThe effects of choline supplementation on physical performance2000n=14
In 14 volunteers, choline citrate (8.4 g) before and during 4 hours of load-carriage exercise raised plasma choline 128% but did not improve run time-to-exhaustion, squat performance, or perceived exertion.
- Effect
- No Benefit
- Dose
- 8.4 g
- Population
- Healthy adults
- Participants
- 14
RCTEffect of choline supplementation on fatigue in trained cyclists1995n=10
In 20 trained cyclists, 2.43 g choline bitartrate before brief or prolonged cycling raised serum choline but did not extend time to exhaustion or increase work performed versus placebo.
- Effect
- No Benefit
- Dose
- 2.43 g
- Population
- Athletes
- Participants
- 10
- Ages
- 23–29
KefirView supplement →
Do not purchase·★★★★★
How we scored this▸
- Small studies in healthy adults and recreational athletes found that drinking kefir (16 ounces once a day or twice a week for up to 15 weeks) did not improve running performance or recovery.
- However, another very small study in untrained men showed that taking kefir powder (20 g mixed with water daily for 4 weeks) helped them last longer during exercise and lowered lactic acid levels compared with a placebo.
Browse 3 studies
RCTMilk or Kefir, in Comparison to Water, Do Not Enhance Running Time-Trial Performance in Endurance Master Athletes2024n=15
In 11 endurance master athletes, 14 days of kefir before a 5 km time trial did not improve running performance versus milk or water, though kefir reduced GI symptom scores after exhaustive exercise.
- Effect
- No Benefit
- Duration
- 14 days
- Population
- Athletes
- Participants
- 15
- Ages
- 40–75
RCTThe Effect of Kefir Supplementation on Improving Human Endurance Exercise Performance and Antifatigue2021n=16
In 16 adults, SYNKEFIR 20 g/day for 28 days increased time to exhaustion by 1.29-fold versus placebo and lowered post-exercise lactate without changing gut microbiota.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 20 g/day
- Population
- Healthy adults
- Participants
- 16
- Ages
- 20–30
RCTThe effects of postexercise consumption of a kefir beverage on performance and recovery during intensive endurance training2015
In 67 adults in a 15-week endurance training study, post-exercise kefir did not improve fitness or body composition but attenuated the rise in C-reactive protein versus control beverage.
- Effect
- No Benefit
- Population
- Adults
- Ages
- 18–24
N-Acetyl Cysteine (NAC)View supplement →
Do not purchase·★★★★★
How we scored this▸
- Some small studies indicate that taking N-acetylcysteine 1200 mg daily for 9 days before exercise or receiving it intravenously before and during exercise might help.
- A single oral dose 60 minutes before exercise does not seem to improve performance.
Browse 4 studies
RCTN-Acetyl cysteine does not improve repeated intense endurance cycling performance of well-trained cyclists2019n=11
An RCT of 11 trained cyclists found NAC (20 mg/kg) did not improve repeated intense endurance cycling performance versus placebo.
- Effect
- No Benefit
- Dose
- 20 mg/kg
- Population
- Athletes
- Participants
- 11
RCTEffect of N-acetylcysteine on cycling performance after intensified training2014
An RCT found 1200 mg/day NAC did not improve cycling time-trial performance after intensified training versus placebo.
- Effect
- No Benefit
- Dose
- 1200 mg/day
- Population
- Athletes
N-Acetylcysteine Attenuates Fatigue Following Repeated-Bouts of Intermittent Exercise: Practical Implications for Tournament Situations2011n=6
A study of 6 men found NAC attenuated fatigue following repeated bouts of intermittent high-intensity exercise versus control.
- Effect
- Benefit
- Population
- ALL patients
- Participants
- 6
RCTN-acetylcysteine attenuates the decline in muscle Na+,K+-pump activity and delays fatigue during prolonged exercise in humans2006
An RCT found NAC (125 mg/kg) attenuated decline in muscle Na+,K+-pump activity and delayed fatigue during prolonged exercise.
- Effect
- Benefit
- Dose
- 125 mg/kg
American GinsengView supplement →
Do not purchase·★★★★★
How we scored this▸
- Early research suggests American ginseng does not help athletic performance.
- Studies found that taking about 600 to 1200 mg daily for one week or 1600 mg daily for 4 weeks did not improve exercise ability, endurance, or heart rate during exercise compared to placebo.
Browse 2 studies
RCTAmerican ginseng supplementation attenuates creatine kinase level induced by submaximal exercise in human beings2005
In 13 active men, 4 weeks of American ginseng reduced exercise-induced creatine kinase leakage during submaximal running but did not improve time to exhaustion or VO2max.
- Effect
- No Benefit
- Duration
- 4 weeks
- Population
- Men
Controlled trialNo ergogenic effect of ginseng ingestion1996
In healthy men, 7 days of Panax ginseng extract 8–16 mg/kg before cycling did not improve VO2, lactate, or time to exhaustion versus placebo in a crossover trial.
- Effect
- No Benefit
- Duration
- 7 days
- Dose
- 16 mg/kg
- Population
- Men
Apple Cider VinegarView supplement →
Do not purchase·★★★★★
How we scored this▸
- Early research suggests apple cider vinegar does not improve endurance in healthy male athletes.
- Drinking 500 mL one hour before a cycling test did not change heart rate, breathing, or blood measures related to exercise when compared to a sports drink.
- It is not known if it works better than a placebo.
Browse 1 study
RCTThe ergogenic activity of cider vinegar: A randomized cross-over, double-blind, clinical trial2020n=7
In 14 athletes, 500 mL apple cider vinegar before endurance exercise performed similarly to a commercial sports drink for glucose, lactate, RER, and heart rate; only ammonia at exhaustion differed.
- Effect
- No Benefit
- Dose
- 500 mL apple cider vinegar (single dose pre-exercise)
- Population
- Athletes
- Participants
- 7
BoronView supplement →
Do not purchase·★★★★★
How we scored this▸
- Taking 2.5 mg of boron daily for 7 weeks does not seem to help increase muscle size or testosterone levels in male bodybuilders.
- Experts, including the International Society of Sports Nutrition, do not recommend boron to improve athletic performance because there isn’t enough proof that it works.
- More research is needed, but right now the evidence suggests that boron supplements are unlikely to boost muscle growth or strength.
Browse 2 studies
ISSN exercise & sports nutrition review update: research & recommendations2018
A 2018 ISSN review summarizes regulation, evaluation, and evidence for sports nutrition supplements, with emphasis on dietary strategies and ergogenic aids for muscle hypertrophy and performance enhancement.
- Population
- Athletes
RCTPlasma boron and the effects of boron supplementation in males1994n=12
In 19 male bodybuilders, 2.5 mg/day boron for 7 weeks raised plasma boron in some men but did not affect total or free testosterone, lean body mass, or strength beyond training effects seen in both groups.
- Effect
- No Benefit
- Duration
- 7 weeks
- Dose
- 2.5 mg/day
- Population
- Men
- Participants
- 12
- Ages
- 20–26
GarlicView supplement →
Do not purchase·★★★★★
How we scored this▸
- It is not clear whether taking garlic supplements helps improve athletic performance.
- Some early studies show that taking a single dose of garlic before exercise might help increase endurance in young athletes.
- But other studies show that taking garlic daily for several weeks does not make cycling faster or improve performance in endurance tests.
- Garlic may help reduce muscle soreness and inflammation after exercise, but it does not seem to boost athletic performance.
Browse 2 studies
RCTGarlic supplementation attenuates cycling exercise-induced oxidative inflammation but fails to improve time trial performance in healthy adults2023
In a crossover RCT of 11 healthy male athletes, 1,000 mg/day garlic extract for 4 weeks reduced exercise-induced oxidative inflammation but did not improve 40-km cycling time trial performance.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 1000 mg/day
- Population
- Healthy adults
Effects of Garlic on Aerobic Performance2000
A study of garlic supplementation in healthy adults found no significant improvement in aerobic exercise performance versus control.
- Effect
- No Benefit
- Population
- Healthy adults
KudzuView supplement →
Do not purchase·★★★★★
How we scored this▸
- It is not known if kudzu by itself improves athletic performance.
- In one small study, healthy men took capsules with kudzu extract plus other ingredients for 15 days and were able to exercise longer before stopping compared to those who took a placebo.
Browse 1 study
RCTSupplementation with soybean peptides, taurine, Pueraria isoflavone, and ginseng saponin complex improves endurance exercise capacity in humans2011
In exercising adults, a soybean peptide/taurine/pueraria isoflavone/ginseng capsule (STPG) for 15 days did not significantly improve exercise performance markers versus placebo.
- Effect
- No Benefit
- Duration
- 15 days
- Dose
- 2 g
- Population
- Men
ResveratrolView supplement →
Do not purchase·★★★★★
How we scored this▸
- Taking resveratrol while doing high-intensity interval training may reduce the normal improvements in fitness and muscle function that come from exercise.
- In a study with young men, those who took resveratrol had smaller increases in aerobic fitness and muscle power after training compared to those who did not.
- Resveratrol also seemed to weaken the muscles’ normal response to exercise at the cellular level.
- This suggests resveratrol might limit some benefits of high-intensity exercise.
Browse 1 study
RCTResveratrol supplementation does not augment performance adaptations or fibre-type-specific responses to high-intensity interval training in humans2014
In 16 recreationally active men over 4 weeks of HIIT, daily resveratrol 150 mg did not augment training-induced fitness or muscle fiber adaptations versus placebo.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 150 mg
- Population
- Men
Vitamin B3 (Niacin)View supplement →
Do not purchase·★★★★★
How we scored this▸
- It is not clear if taking niacin helps with sports performance.
- Studies in men who do not usually exercise showed that a single large dose of niacin before cycling did not make them stronger or help them last longer, and results were actually worse than taking caffeine.
- Supplements with a small amount of niacin plus other ingredients like caffeine, pepper, or capsicum also did not improve exercise results compared to just taking a placebo.
Browse 2 studies
Niacin supplementation impairs exercise performance2023
A study found that 5 mg/kg similarly, habitual caffeine use (p=0.72), habitual aerobic exercise (p=0.08), and habitual resistance exercise (p=0.39) did not significantly affect total work performed.
- Effect
- No Benefit
- Dose
- 5 mg/kg
RCTAcute effects of a caffeine-containing supplement on bench press and leg extension strength and time to exhaustion during cycle ergometry2010
A randomized trial found that 400 mg/day the results indicated that the SUPP had no effect on 1RM bench press strength, 1RM leg extension strength, or TTE at 80% VO2peak.
- Effect
- No Benefit
- Dose
- 400 mg/day
- Population
- Men
- Avg age
- 23±2.6
Vitamin B6View supplement →
Do not purchase·★★★★★
How we scored this▸
- Vitamin B6 alone has not been studied for athletic performance.
- One small study tested a combination of vitamin B6 (31.5 mg), magnesium (1350 mg), and zinc (90 mg) taken at bedtime for three nights in sleep-deprived athletes and found it did not improve weightlifting compared to a placebo.
Browse 2 studies
RCTEffects of Supplementing Zinc Magnesium Aspartate on Sleep Quality and Submaximal Weightlifting Performance, following Two Consecutive Nights of Partial Sleep Deprivation2024n=12
A double-blind crossover RCT of 16 sleep-deprived trained males found ZMA supplementation for two nights had no significant effect on sleep quality or next-morning grip strength, bench press, or back squat performance.
- Effect
- No Benefit
- Participants
- 12
Pyridoxine (B6) suppresses the rise in prolactin and increases the rise in growth hormone induced by exercise1982
A study in adults found that 600 mg pyridoxine (B6) suppresses the rise in prolactin and increases the rise in growth hormone induced by exercise..
- Dose
- 600 mg
- Population
- Adults
Yerba MateView supplement →
Do not purchase·★★★★★
How we scored this▸
- It is not certain if drinking yerba mate improves athletic performance.
- A small study found that taking 5 grams of yerba mate daily for 5 days before cycling helped athletes finish 2% faster and slightly improved power compared to placebo.
- More research is needed to confirm these effects.
Browse 1 study
RCTMetabolic and Performance Effects of Yerba Mate on Well-trained Cyclists2017n=9
In an RCT of 9 participants, 5 g/day, respiratory exchange ratio during TT indicated carbohydrate dependence and did not differ between treatments (PL, 0.95 ± 0.03 (SD); YM, 0.95 ± 0.02).
- Effect
- No Benefit
- Duration
- 5 days
- Dose
- 5 g/day
- Population
- Athletes
- Participants
- 9
Evidence visualised
Same ratings as above, aggregated so you can see coverage and imbalance.
| Supplement | DEX | Studies | Meta-analyses | Share |
|---|---|---|---|---|
| Caffeine | ★★★★★88% | 67 | 20 | 15% |
| Creatine | ★★★★★88% | 66 | 3 | 14% |
| Beta-Alanine | ★★★★★68% | 56 | 7 | 12% |
| Branched Chain Amino Acids (BCAAs) | ★★★★★56% | 28 | 1 | 6% |
| L-Carnitine | ★★★★★40% | 22 | 0 | 5% |
| Whey Protein | ★★★★★76% | 18 | 1 | 4% |
| Taurine | ★★★★★56% | 16 | 1 | 3% |
| L-Citrulline | ★★★★★68% | 15 | 2 | 3% |
| Panax Ginseng | ★★★★★44% | 15 | 1 | 3% |
| Rhodiola | ★★★★★68% | 15 | 7 | 3% |
| Casein Protein | ★★★★★44% | 12 | 0 | 3% |
| Coenzyme Q10 | ★★★★★44% | 12 | 0 | 3% |
| Tyrosine | ★★★★★40% | 11 | 0 | 2% |
| Ashwagandha | ★★★★★72% | 7 | 2 | 2% |
| Eleuthero | ★★★★★40% | 7 | 0 | 2% |
| Glutamine | ★★★★★40% | 7 | 1 | 2% |
| Magnesium | ★★★★★40% | 7 | 0 | 2% |
| Melatonin | ★★★★★40% | 6 | 0 | 1% |
| Quercetin | ★★★★★40% | 6 | 0 | 1% |
| Phosphatidylserine | ★★★★★52% | 5 | 0 | 1% |
| Tongkat Ali | ★★★★★52% | 5 | 0 | 1% |
| Vitamin D | ★★★★★40% | 5 | 0 | 1% |
| Echinacea | ★★★★★40% | 4 | 1 | <1% |
| Green Tea | ★★★★★48% | 4 | 0 | <1% |
| N-Acetyl Cysteine (NAC) | ★★★★★36% | 4 | 0 | <1% |
| Astaxanthin | ★★★★★48% | 3 | 0 | <1% |
| Choline | ★★★★★36% | 3 | 0 | <1% |
| Iron | ★★★★★52% | 3 | 2 | <1% |
| Kefir | ★★★★★36% | 3 | 0 | <1% |
| Acetyl-L-Carnitine | ★★★★★64% | 2 | 0 | <1% |
| American Ginseng | ★★★★★32% | 2 | 0 | <1% |
| Boron | ★★★★★32% | 2 | 0 | <1% |
| Garcinia Cambogia | ★★★★★44% | 2 | 0 | <1% |
| Garlic | ★★★★★32% | 2 | 0 | <1% |
| L-Tryptophan | ★★★★★44% | 2 | 0 | <1% |
| Vitamin B3 (Niacin) | ★★★★★32% | 2 | 0 | <1% |
| Vitamin B6 | ★★★★★32% | 2 | 0 | <1% |
| Yohimbe | ★★★★★44% | 2 | 0 | <1% |
| Acai | ★★★★★44% | 1 | 0 | <1% |
| Apple Cider Vinegar | ★★★★★32% | 1 | 0 | <1% |
| Cocoa | ★★★★★40% | 1 | 0 | <1% |
| Kudzu | ★★★★★32% | 1 | 0 | <1% |
| Maca | ★★★★★44% | 1 | 0 | <1% |
| Nicotinamide Riboside | ★★★★★44% | 1 | 0 | <1% |
| Reishi | ★★★★★44% | 1 | 0 | <1% |
| Resveratrol | ★★★★★32% | 1 | 0 | <1% |
| Theanine | ★★★★★44% | 1 | 0 | <1% |
| Vitamin K | ★★★★★44% | 1 | 0 | <1% |
| Yerba Mate | ★★★★★32% | 1 | 0 | <1% |