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 VO(2max) 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 VO(2max) 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 VO(2max), 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.