Research summary · Nutrition and hydration
A rowing supplement trial highlights the trade-off between performance and sleep
Fourteen male university rowers completed 2,000-metre ergometer tests after caffeine, paraxanthine, their combination or placebo. The study assessed completion time, power and heart rate, alongside questionnaire measures of sleep quality and daytime sleepiness.
- Publication year
- 2026
- First published online
- Publication type
- Randomized double-blind four-condition crossover trial
- Journal
- Journal of the International Society of Sports Nutrition
- Population / context
- Rowing · University-level male athletes
What the publication reports
The combined condition produced faster performance and greater mean power than placebo, with a small reported effect. Neither compound alone showed clear performance superiority in this sample. Caffeine-containing conditions were associated with poorer subjective sleep quality, while paraxanthine alone had more favourable sleep-related reports.
Limits and interpretation
The trial was small and included only men. Sleep was self-reported rather than objectively monitored. Better sleep ratings do not establish paraxanthine as a safe long-term substitute, and a combined-treatment result does not prove that either ingredient independently improves rowing performance.
Read the source
Consult the original record for the full author list, methods, references, funding and competing-interest disclosures.
Comparative effects of caffeine and paraxanthine on rowing performance and sleep quality: a randomized crossover study
Original publication / indexed recordPMID: 41918248DOI: 10.1080/15502783.2026.2650339Full text at the sourceReader discussion
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