Effects of betaine supplementation on endurance exercise performance: a systematic review.

PURPOSE

Betaine has been studied for its potential ergogenic effects on strength, power, and body composition. However, its influence on endurance exercise performance remain relatively underexplored. This systematic review aimed to evaluate the impact of betaine supplementation on endurance exercise performance, as assessed through a combination of physiological measures and performance-based outcomes.

METHODS

A comprehensive literature search was conducted using PubMed, the Cochrane Library, and EMBASE to identify studies comparing betaine supplementation with a placebo on endurance performance outcomes in healthy individuals. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and study quality was assessed using the Cochrane Risk of Bias Tool.

RESULTS

A total of five studies (three parallel-design and two crossover-design) met the inclusion criteria. Of these, two studies demonstrated a significant interaction effect on maximum oxygen consumption and mean power at the latter stage of the Wingate Anaerobic Test, two reported a main effect of treatment on mean power, peak power, and oxygen consumption, and one found significant differences in oxygen consumption and blood lactate levels. All included studies were evaluated as having a high risk of bias.

CONCLUSION

These findings highlight the paucity of evidence regarding the ergogenic potential of betaine in endurance exercise performance and underscore the need for additional, more rigorous research to determine its effectiveness.