Study note • PMID 33939237
Belief in caffeine's ergogenic effect on cognitive function and endurance performance: A sham dose-response study.
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: randomized trial.
- • Population relevance: mixed/unclear athlete specificity.
- • Consistency: single-study evidence.
- • Practical recommendation depends on tolerance, context, and whether it protects training consistency.
ELI5
In plain language
This study aimed to determine if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and/or running performance. (randomized trial; n=6 participants).
The abstract doesn’t indicate a clear change in Time-trial performance under the tested conditions. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.
Takeaways
What the abstract suggests
- • Study question: This study aimed to determine if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and/or running performance.
- • The abstract doesn’t indicate a clear change in Time-trial performance under the tested conditions.
- • Population: n=6 participants.
- • Protocol cues (title/abstract): 100mg • 300mg • 3.75min • 3.85min • 3.71min • 3.52min.
Protocol
Protocol (as reported)
- • Intervention/exposure: caffeine (vs comparison group).
- • Dose/time/duration cues in abstract/title: 100mg • 300mg • 3.75min • 3.85min • 3.71min • 3.52min • 1.87min • 1.75min.
- • 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=6 participants) 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: randomized trial.
- • Population: n=6 participants.
- • Comparator: comparison group.
- • Outcomes measured: Time-trial performance, Time to exhaustion.
- • Protocol cues mentioned: 100mg • 300mg • 3.75min • 3.85min • 3.71min • 3.52min • 1.87min • 1.75min.
- • Source: PubMed PMID 33939237 (2021) — Human psychopharmacology.
Results excerpt
What the abstract reports
“Belief (n = 9) (LD: 48.93 +/- 3.71min vs.”
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).
- • Single studies often don’t generalize to your event, history, and training load; treat results as a starting point.
- • If your context differs (elite vs recreational; cycling vs running), adjust expectations and be conservative.
- • This is performance information, not medical advice.
Adaptive AI coach for iPhone
Meet your adaptive AI coach.
Tell your coach what you are training for. It builds the plan, follows the work you complete, and adapts upcoming training when recovery, your schedule, or real life changes.
Keep going
Performance Science Lab
Research summaries for endurance athletes, with study context, practical protocols, and clear limitations.
Supplements performance research
Supplements are optional. Only a few reliably move the needle, and context matters.
Caffeine for endurance performance: a practical protocol
Evidence-informed protocol: Caffeine for endurance performance: a practical protocol. Practical steps, who it helps, and what to watch out for.