Mitochondria-targeted antioxidant supplementation improves 8 km time trial performance in middle-aged trained male cyclists

Abstract BackgroundExercise increases skeletal muscle ROS production, which may contribute to the onset of muscular fatigue and impair athletic performance. Mitochondria-targeted antioxidants such as MitoQ are becoming popular amongst active individuals as they are designed to accumulate within mitochondria and may provide targeted protection against exercise-induced oxidative stress. However, the effect of MitoQ supplementation on cycling performance is currently unknown. Here we investigate whether MitoQ supplementation can improve cycling performance measured as time to complete an 8 km time trial.MethodIn a randomised, double-blind, placebo-controlled crossover study, 19 middle-aged (age: 44 ± 4 years) recreationally trained (VO2peak: 58.5 ± 6.2 ml·kg·min− 1, distance cycled per week during six months prior to study enrollment: 158.3 ± 58.4 km) male cyclists completed 45 min cycling at 70% VO2peak followed by an 8 km time trial after 28 days of supplementation with MitoQ (20 mg/day) and a placebo. Free F2-isoprostanes were measured in plasma samples collected at rest, after 45 min cycling at 70% VO2peak and after completion of the time trial. Respiratory gases and measures of rate of perceived exertion (RPE) were also collected.ResultsMean completion time for the time trial was 1.3% faster with MitoQ (12.91 ± 0.94 min) compared to placebo (13.09 ± 0.95 min, P = 0.04 95% CI [0.05, 2.64], d = 0.2). There was no difference in RPE during the time trial between conditions (P = 0.82) despite average power output during the time trial being higher following MitoQ supplementation (280 ± 53 W) compared to placebo (270 ± 51 W, P = 0.04). Plasma F2-isoprostanes were lower on completion of the time trial following MitoQ supplementation (35.89 ± 13.6 pg/ml) compared to placebo (44.7 ± 16.9 pg/ml P = 0.03).ConclusionThese data suggest that MitoQ supplementation may be an effective nutritional strategy to attenuate exercise-induced increases in oxidative damage to lipids and improve cycling performance.Trial registrationThis study was registered with the Australia New Zealand Clinical Trial Registry (ACTRN12619000451101) on 19th March 2019.