Quercetin Supplementation Does Not Attenuate Exercise Performance and Body Composition in Young Female Swimmers

BACKGROUND Quercetin is a health-enhancing antioxidant bioflavonoid (1-3). This flavonoid occurs in variety of natural fruits and vegetables such as apple, cranberry, onion, broccoli, and teas. Many studies have shown that quercetin has possible positive effects on exercise performance. The aim of this study is the evaluation of effects of quercetin supplementation on VO2max and exercise performance in female athletes. METHODS This study was done on 26 young female swimmers. Participants were assigned in to groups and supplemented orally for 8 weeks with either Quercetin (Solaray(®), USA, Inc) or placebo (dextrose). Before and after intervention, athletes performed a continuous graded exercise test (GXT) on an electronically braked cycle ergometer (Lode, The Netherlands) to determine VO2max and time to exhaustion (TTE). RESULTS Participants in the quercetin group consumed higher energy and protein and lower carbohydrates and fats. There was no significant differences in VO2max, TTE, lactate, and body fat between pre- and post-supplementation neither in the placebo group nor in the quercetin group. CONCLUSIONS It is concluded that quercetin supplementation (1000 g/day) for 8 weeks in female athletes didn't show any significant association with exercise performance.