Study note • PMID 36615805
Effects of Caffeine Intake on Endurance Running Performance and Time to Exhaustion: A Systematic Review and Meta-Analysis.
How to use this page
This note summarizes one study record. Check the participants, methods, results, and limitations before applying it to training.
- • Design signal: systematic review / meta-analysis.
- • Population relevance: athlete/trained context.
- • Consistency: synthesis evidence present.
- • Practical recommendation depends on tolerance, context, and whether it protects training consistency.
ELI5
In plain language
Caffeine (1,3,7-trimethylxanthine) is one of the most widely consumed performance-enhancing substances in sport due to its well-established ergogenic effects. (systematic review / meta-analysis; n=254 trained runners).
In this systematic review / meta-analysis, the abstract is mixed or unclear for Time-trial performance, Time to exhaustion. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.
Takeaways
What the abstract suggests
- • Study question: Caffeine (1,3,7-trimethylxanthine) is one of the most widely consumed performance-enhancing substances in sport due to its well-established ergogenic effects.
- • In this systematic review / meta-analysis, the abstract is mixed or unclear for Time-trial performance, Time to exhaustion.
- • Population: n=254 trained runners.
- • Protocol cues (title/abstract): 9 mg/kg.
Protocol
Protocol (as reported)
- • Intervention/exposure: caffeine.
- • Dose/time/duration cues in abstract/title: 9 mg/kg.
- • Outcomes: Time-trial performance, Time to exhaustion.
- • Replication note: abstracts often omit adherence and timing; confirm details before changing training or supplementation.
Fit
Who it may help, and who should be cautious
Who it helps
- • Athletes similar to the study population (n=254 trained runners) working on supplements.
- • Athletes who can measure Time-trial performance, Time to exhaustion with a repeatable workout or time-trial effort.
Who should be cautious
- • If you have symptoms or conditions that make the intervention risky, get professional guidance.
- • If you’re near race day and can’t safely test, defer the experiment.
Methods
What the study actually did
- • Design: systematic review / meta-analysis (double-blind, placebo-controlled).
- • Population: n=254 trained runners.
- • Outcomes measured: Time-trial performance, Time to exhaustion.
- • Protocol cues mentioned: 9 mg/kg.
- • Source: PubMed PMID 36615805 (2022) — Nutrients.
Results excerpt
What the abstract reports
“A total of 21 randomized controlled trials were included in the analysis, with caffeine doses ranging between 3 and 9 mg/kg.”
Note: excerpts are short; for full context, read the paper.
Limits
Limitations and bias
- • Abstract-only summaries can miss critical details (population, protocol, adherence, and context).
- • Reviews and consensus statements mix protocols and populations; recommendations may not match your exact constraints.
- • If your context differs (elite vs recreational; cycling vs running), adjust expectations and be conservative.
- • This is performance information, not medical advice.
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