The Study
Time of Day and Training Status Both Impact the Efficacy of Caffeine for Short Duration Cycling Performance
This study gave people caffeine or a sugar pill and saw how fast they rode a bike at different times of day. Because they randomly picked who got what, we can say caffeine probably helped some people ride faster—but we can't say it will help everyone the same way.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists gave cyclists a caffeine pill and had them race a short bike course in the morning and evening, with and without caffeine, to see when it helped most.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 564 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1A 2-3% improvement in a 3-km race is meaningful — it could mean winning or losing in competitive cycling.
- 2Caffeine made all cyclists 2.3% faster in the morning and 1.4% faster in the evening.
- 3Untrained cyclists got a bigger boost in the evening (2.9%) than trained ones.
- 4Trained cyclists only got faster in the morning.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrients
Year
2016
Authors
J. Boyett, G. E. Giersch, C. Womack, M. Saunders, C. A. Hughey, Hannah M. Daley, N. Luden
Related Content
Claims (5)
Caffeine taken in the morning improves physical performance similarly in trained athletes and untrained individuals.
For adult male cyclists, taking 6 mg of caffeine per kilogram of body weight improves 3-km cycling time trial performance by 2.3% in the morning and by 1.4% in the evening, with a larger improvement in the morning.
Evening caffeine improves 3-km cycling performance by 2.9% in untrained male cyclists but does not improve performance in trained male cyclists.
Taking 6 mg of caffeine per kilogram of body weight does not increase the maximum force produced by muscles during fast contractions in male cyclists.
Caffeine improves cycling performance equally in the morning and evening, and this effect is not due to differences in how much caffeine is in the blood at those times.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.