Effect of ubidecarenone oral treatment on aerobic power in middle-aged trained subjects

BACKGROUND: Coenzyme Q10 (CoQ10) plays an important role in oxidative mithocondrial phosphorylation and prevents lipid peroxidation in biological membranes. During sustained physical exercise, reactive oxygen species (ROS) production increase through several mechanism; one of them is the purine nucleotide cycle activation by shifting xanthine-dehydrogenase to xanthine-oxidase during AMP breakdown. The aim of this study was to evaluate the effect of CoQ10 treatment on aerobic power. METHODS: Experimental design: according to a single blind study design, 28 health male cyclists were randomized into two groups (CoQ10 or placebo) and remained on treatments for eight weeks; there were 5 drop-outs and only 23 subjects were completely evaluated. Before and at the end of the eight weeks, cyclists underwent cardiopulmonary exercise testing. Measures: a software system performed the necessary calculations to obtain the following parameters: oxygen uptake, CO2 production, minute ventilation, oxygen ventilatory equivalent, carbon dioxide ventilatory equivalent, oxygen pulse. Finally oxygen peak and anaerobic threshold were determined. Moreover blood inosine, hypoxanthine, xanthine, lactate and CoQ10 levels were measured before and immediately after each test. RESULTS: The results of this study showed that at the end of the eight weeks there was no difference between the two groups concerning physiological and metabolic parameters, but muscular exhaustion was reached at higher workloads in the CoQ10 group. CONCLUSIONS: In our experience ubidecarenone oral treatment does not improve aerobic power. The little improvement of tolerance to higher workloads may be due to the antioxidant activity of CoQ10.