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Research guide

Supplements performance research

Supplements are optional. Only a few reliably move the needle, and context matters.

Updated Jul 22, 2026

Review the evidence

Performance Science Lab

Supplements lab

Supplements are optional. Only a few reliably move the needle, and context matters.

Start here

  • Food and sleep first — then the few evidence-backed supplements (e.g., caffeine) with a protocol.
  • Avoid anything banned/unsafe; this lab excludes red-line topics.
  • Test in training, never first on race day.

Topic guides

Practical starting points to test conservatively.

Outcomes this affects

Study library (reference)

Individual studies for deeper reading.

studyOpen

Effects of Caffeine Intake on Endurance Running Performance and Time to Exhaustion: A Systematic Review and Meta-Analysis.

PMID 36615805 (2022): caffeine — Time-trial performance, Time to exhaustion (study note for endurance athletes).

studyOpen

Ergogenic effects of supplement combinations on endurance performance: a systematic review and meta-analysis of randomized controlled trials.

PMID 40619880 (2025): caffeine, bicarbonate — Time-trial performance, Time to exhaustion (study note for endurance athletes).

studyOpen

Effect of Pre-Exercise Caffeine Intake on Endurance Performance and Core Temperature Regulation During Exercise in the Heat: A Systematic Review with Meta-Analysis.

PMID 35616851 (2022): caffeine — Time-trial performance (study note for endurance athletes).

studyOpen

Effects of caffeine chewing gum supplementation on exercise performance: A systematic review and meta-analysis.

PMID 35239468 (2023): caffeine — Time-trial performance (study note for endurance athletes).

studyOpen

Effects of caffeine supplementation on muscle endurance, maximum strength, and perceived exertion in adults submitted to strength training: a systematic review and meta-analyses.

PMID 32551869 (2021): caffeine — Time-trial performance, Time to exhaustion (study note for endurance athletes).

studyOpen

Caffeine and Bicarbonate for Speed. A Meta-Analysis of Legal Supplements Potential for Improving Intense Endurance Exercise Performance.

PMID 28536531 (2017): caffeine, nitrate — Time-trial performance, Time to exhaustion (study note for endurance athletes).

studyOpen

Acute Effects of Caffeine Supplementation on Physical Performance, Physiological Responses, Perceived Exertion, and Technical-Tactical Skills in Combat Sports: A Systematic Review and Meta-Analysis.

PMID 35889953 (2022): caffeine — Time-trial performance (study note for endurance athletes).

studyOpen

Nutritional Ergogenic Aids in Cycling: A Systematic Review.

PMID 38892701 (2024): caffeine, nitrate — Time-trial performance, Time to exhaustion (study note for endurance athletes).

studyOpen

Caffeine Placebo Effect in Sport and Exercise: A Systematic Review.

PMID 39339818 (2024): caffeine — Time-trial performance, Time to exhaustion (study note for endurance athletes).

studyOpen

Effect of caffeine ingestion on time trial performance in cyclists: a systematic review and meta-analysis.

PMID 38836626 (2024): caffeine — Time-trial performance, Time to exhaustion (study note for endurance athletes).

studyOpen

Effects of taurine combined with caffeine on repetitive sprint exercise performance and cognition in a hypoxic environment.

PMID 39948152 (2025): caffeine — Time-trial performance, Time to exhaustion (study note for endurance athletes).

studyOpen

Performance-enhancing effects of caffeine and L-Theanine among Iranian elite wrestlers: a focus on cognitive and specific physical performance.

PMID 40977612 (2025): caffeine — Time-trial performance, Time to exhaustion (study note for endurance athletes).

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Sources