Chronic L-Carnitine Supplementation on Exercise Performance, Blood Lactate, and Exercise-Induced Oxidative Stress in Resistance-Trained Males

The purpose of the present study is to investigate the effect of Chronic L-Carnitine Supplementation on Exercise Performance, Blood Lactate, and Exercise-Induced Oxidative Stress in Resistance-Trained Males.

We examined 35 resistance-trained (1y) male participants (25±2y, 79.8±8.9 kg, 16.1±5.53% body fat) for 9-wk of L-carnitine supplementation in conjunction with resistance training on exercise performance, blood lactate, and exercise-induced oxidative stress. Randomized, placebo-controlled, double-blind treatment of a (1) no intervention, no supplement Control (CON, n=12), (2) maltodextrose Placebo (PLA, 2 g/d, n=11) or (3) L-carnitine (LCR, 2 g/d, n=12). Exercise performance, post-exercise blood lactate (BL) and oxidative stress markers were analyzed at weeks 3, 6, and 9. The PLA and LCR groups followed a specific resistance training program (4 d/w, upper body/lower body split) for a 9-wk. Data were analyzed by GLM and presented as mean (SD) or change (95% CI). Primary outcomes were total lifting volume for the bench (BP) and leg press (LP).

The results a significant increase in BP lifting volume at wk-6 (139 kg, 95% CI 49.1, 230) and wk-9 (238 kg, 95% CI 132, 343) for LCR. Similar results were observed for LP. We also observed a significant increase in Wingate mean power (63.4 W, 95% CI 30.5, 96.3) and peak power (239 W/kg, 95% CI 104, 374) at wk-9 for LCR as well as a significant reduction in post-exercise BL levels and oxidative stress responses. No differences were observed in body composition.

These findings indicate that LCR supplementation improves exercise performance and attenuates the blood lactate and oxidative stress response to resistance training.