ArticleBiology of sport2021
Caffeine metabolites are associated with different forms of caffeine supplementation and with perceived exertion during endurance exercise.
Article in Biology of sport, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
6 citing papers in PubMed, 3 syntheses or guidelines pooled it, 10 citations in OpenAlex.
- Does acute caffeine ingestion improve high-intensity interval exercise performance? A systematic review and meta-analysis.Frontiers in physiology · 2026Pooled it
- Effects of Caffeine Dose and Administration Method on Time-Trial Performance: A Systematic Review and Network Meta-Analysis.Nutrients · 2025Pooled it
- Effects of Caffeinated Chewing Gum on Exercise Performance and Physiological Responses: A Systematic Review.Nutrients · 2024Pooled it
- The Effect of CYP1A2 Gene Polymorphisms on Caffeine Pharmacokinetics and Exercise Performance in Male Recreational Athletes.European journal of sport science · 2026Trial
- Caffeinated chewing gum produces comparable strength and power gains to capsules with fewer side effects in resistance-trained men.Journal of the International Society of Sports Nutrition · 2025Trial
- Caffeine mouth rinse enhances performance, fatigue tolerance and reduces muscle activity during moderate-intensity cycling.Biology of sport · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
This investigation compared the urine caffeine metabolites produced from different forms of caffeine supplementation given to runners 15 minutes before a series of 5-km running trials. Fourteen amateur competitive runners completed a series of self-paced outdoor time trials following ingestion of placebo or one of three alternate forms of caffeine supplement. Trials were randomized in a crossover design with equivalent doses of caffeine (4.0 mg.kg
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.