Effects of four weeks of supplementation with coenzyme Q10 on aerobic power and exercise economy
Coenzyme Q10 (CoQ10) plays several crucial roles in the body, mainly acting as a redox electron carrier in the mitochondria, being an essential antioxidant, and influencing the stability and function of membranes. Supplementation with CoQ10 has shown beneficial effects in cardiac and other types of patients. However, limited and conflicting information exists in the literature on performance-enhancing effects of CoQ10 in healthy and athletic populations. This study investigated the effects of four-week CoQ10 supplementation on aerobic power (VO2max) and exercise economy (oxygen consumption at steady state exercise) in six healthy, physically active men (mean age 29.7+/-SD7.2 years and VO2max 39.4+/-SD8.5 mL.kg-1.min-1), in a self-control, single-blind design. Participants started with a two-week placebo run-in phase, followed by two weeks of CoQ10 supplementation at a daily dosage of 150 mg, then two weeks of CoQ10 (150 mg) plus 1000 IU vitamin E per day, followed by a final two-week of placebo wash-out phase. A three-stage cycle economy test (four minutes at each of 50, 100, and 150 watts with one minute resting interval), followed by a VO2max test (workload increased by 25 watts every minute till exhaustion), were performed pre supplementation and at the end of each two-week phase. Blood samples were taken pre and post each VO2max test, and biopsy samples were obtained from the vastus lateralis muscle pre and post the CoQ10 supplementation phase, for measurement of plasma and muscle CoQ10 concentrations. Results showed that the mean plasma CoQ10 concentration was elevated significantly in response to the supplementation (p<0.05, as detected by repeated measures ANOVA with Bonferroni adjustment) and returned to normal level following the wash-out period, however, it did not vary significantly pre-post each test. Muscle CoQ10 concentration was not significantly changed (p>0,05, paired t-test). The VO2max values and exercise economy in repeated tests were not significantly altered (P>0.05). This study provided new evidence that 1) the supplementation protocol did not affect exercise economy during submaximal cycling at steady state; 2) the single VO2max test did not affect plasma CoQ10 concentration; and 3) the co-supplementation of CoQ10 with vitamin E did not induce additional beneficial effect in response to the prescribed exercise. These could be due to that either the mitochondrial membrane in the muscle is normally saturated with CoQ10, or the selected exercise testing protocol and variables are not sensitive enough to detect the effects of CoQ10 supplementation on cellular function.
Zhou, S, Zhang, Y, Davie, AJ, Marshall-Gradisnik, SM, Wang, JX, Hu, H & Brushett, DJ 2003, 'Effects of four weeks of supplementation with coenzyme Q10 on aerobic power and exercise economy', Second annual conference of the Society of Chinese Scholars on Exercise Physiology and Fitness: Health and fitness for all, Macau, China, 24-27 November, Macau Polytechnic Institute and The Society of Chinese Scholars on Exercise Physiology and Fitness, Macau, China.
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