Quick Answer
Paraxanthine Exercise Performance Randomized Trial has evidence relevant to strength of evidence and what the studies can or cannot prove, but conclusions should stay close to the cited sources. One representative finding is: Perceived exertion was lowest during steady-state exercise in the PRE condition (P Conclusion In summary, ingestion of a pre-exercise supplement containing 200 mg caffeine 35 min before exercise appeared optimal for improved performance in a subsequent fatiguing time trial, possibly by reducing the perception of effort.
Key Takeaways
- 01Perceived exertion was lowest during steady-state exercise in the PRE condition (P Conclusion In summary, ingestion of a pre-exercise supplement containing 200 mg caffeine 35 min before exercise appeared optimal for improved performance in a subsequent fatiguing time trial, possibly by reducing the perception of effort. [Davenport AD (2020)]
- 02Whether this was due to increased circulating paraxanthine requires further investigation. [Davenport AD (2020)]
- 03Background Pre-exercise supplements containing low doses of caffeine improve endurance exercise performance, but the most efficacious time for consumption before intense endurance exercise remains unclear, as does the contribution of caffeine metabolism. [Davenport AD (2020)]
- 04Methods This study assessed the timing of a commercially available supplement containing 200 mg of caffeine, 1600 mg of β-alanine and 1000 mg of quercetin [Beachbody Performance Energize, Beachbody LLC, USA] on exercise performance, perception of effort and plasma caffeine metabolites. [Davenport AD (2020)]
The current Migaku evidence database contains 2 reusable source documents for Paraxanthine Exercise Performance Randomized Trial. This answer focuses on strength of evidence and what the studies can or cannot prove.
- Perceived exertion was lowest during steady-state exercise in the PRE condition (P Conclusion In summary, ingestion of a pre-exercise supplement containing 200 mg caffeine 35 min before exercise appeared optimal for improved performance in a subsequent fatiguing time trial, possibly by reducing the perception of effort. [Davenport AD (2020); evidence level 2]
- Whether this was due to increased circulating paraxanthine requires further investigation. [Davenport AD (2020); evidence level 2]
- Background Pre-exercise supplements containing low doses of caffeine improve endurance exercise performance, but the most efficacious time for consumption before intense endurance exercise remains unclear, as does the contribution of caffeine metabolism. [Davenport AD (2020); evidence level 2]
- Methods This study assessed the timing of a commercially available supplement containing 200 mg of caffeine, 1600 mg of β-alanine and 1000 mg of quercetin [Beachbody Performance Energize, Beachbody LLC, USA] on exercise performance, perception of effort and plasma caffeine metabolites. [Davenport AD (2020); evidence level 2]
- This study examined the effects of caffeine consumption on endurance exercise performance, and the influence of CYP1A2 gene polymorphisms in caffeine pharmacokinetics and exercise performance. [Masters C (2026); evidence level 4]
Evidence levels are sorting aids, not final clinical grades. Level 1 usually indicates systematic-review style evidence, level 2 indicates randomized trials or public-health guidance, and lower levels need more cautious wording.
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Sources