Acute Capsaicin Supplementation Improves 400 and 3000 Meters Running Time-trial Performance in a Distance-dependent Way

Abstract

Ergogenic effect of capsaicin has been shown in middle-distance time trial (1500 meters) but not in repeated maximal sprints indicating the need of explore exercises with different metabolic demands. PURPOSE: The purpose of this study was to investigate the acute effect of capsaicin supplementation on short (400 m) and middle distance (3000 m) running time-trial performance, maximum heart rate and rate of perceived exertion in physically active adults. METHODS: Twelve physically active men (age= 28.6±5.4 y) completed four randomized, double-blind trials: Capsaicin condition (12 mg) or a placebo condition. Forty-five minutes after supplement consumption, the participants performed a randomized 400- or 3000-meters running time trial. Time (in seconds) was recorded. Heart rate was analyzed at rest and immediately post-exercise, and the rate of perceived exertion (RPE) was collected immediately after exercise. The effect of capsaicin on time-trial performance, maximum heart rate and rate of perceived exertion during short (400 m) and middle distance (3000 m) running were analyzed via a Paired t test. In addition, the effect size (ES, 90% confidence interval [CI]) and magnitude-based inference statistics in the selected variables were calculated. RESULTS: For 400 m time-trial (Capsaicin= 66.4 + 4.2 sec vs Placebo= 67.1 + 4.8 sec, t= 2.250, p= 0.046) and 3000 m time-trial (Capsaicin= 876.2 + 76.1 sec vs Placebo= 905.1 + 73.3 sec, t= 2.848, p= 0.016) the time in seconds was significantly lesser in the capsaicin compared to placebo. Capsaicin showed a likely small improvement of performance in the 3000 m (d= 0.40, IC 90%= -0.60 to -0.14) and likely trivial in the 400 m (d= 0.13, IC 90%= -0.24 to -0.03). There was no statistically significant difference for the maximum heart rate (400m: p=0.114; 3000m: p= 0.319) and RPE (400m: p=0.615; 3000m: p= 0.438). CONCLUSION: In summary, acute capsaicin supplementation improved 400 m and 3000 m running time-trial performance in a distance-dependent way without modifying RPE and maximum heart rate in physically active adults. Furthermore, the present study showed a meaningful improvement in the performance during 3000 m running time-trial.