Higher relative doses of acute capsaicin supplementation enhance the resistance training performance in trained men

Background Capsaicin supplementation has been proposed as an ergogenic aid, but findings remain inconsistent, partly due to fixed absolute doses Objective This study aimed to examine the acute effects of capsaicin supplementation at different body-mass-relative doses on strength performance and psychophysiological responses Methods Nineteen resistance-trained men (23.4 ± 3.2 years) completed a randomized, double-blind, crossover trial. Participants ingested either a low dose of capsaicin (0.15 mg/kg; LCAP), a high dose (0.35 mg/kg; HCAP), or a placebo (PLA), 45 min before performing four sets of back squat exercise. Total volume (TV), movement speed (MS), blood lactate, and rating of perceived exertion (RPE) were assessed Results HCAP significantly increased TV compared to LCAP (p=0.042, d=0.32) and PLA (p=0.033, d=0.44). LCAP did not differ from PLA (p=1.00). No significant differences were found for MS (p=0.495), lactate (p=0.733), or RPE (p=0.554) among the experimental conditions Conclusion Acute capsaicin supplementation enhances resistance exercise performance only at higher relative doses (0.35 mg/kg), without altering psychophysiological responses. These findings highlight the importance of individualized, body-mass-relative dosing when applying capsaicin as an ergogenic aid.