Effect of quercetin supplementation on maximal oxygen uptake in men and women

Abstract

Quercetin is a naturally occurring flavonoid with anti-oxidant and anti-inflammatory properties. The effect of quercetin supplementation on maximal oxygen uptake ([Vdot]O2max) is unknown. The purpose of this investigation was to test the effects of quercetin supplementation on [Vdot]O2max in untrained, sedentary individuals. After baseline treadmill [Vdot]O2max testing, 11 participants (5 males, 6 females) ingested either placebo or quercetin-supplemented (1000 mg · day−1) food bars in a randomized, double-blind, counterbalanced, crossover research design. The participants ingested food bars for six consecutive mornings (5 days). On the sixth morning, participants underwent repeat [Vdot]O2max testing. After a 22 day wash-out, the participants repeated baseline [Vdot]O2max testing, daily consumption of the opposite food bars, and post-supplementation [Vdot]O2max testing. The condition × time interaction for [Vdot]O2max was non-significant when expressed in absolute (litres · min−1; P = 0.929) and relative (ml · kg−1 · min−1; P = 0.778) terms. These findings were similar when taking sex into account (P > 0.05). The mean difference in [Vdot]O2max change from pre to post between groups (quercetin vs. placebo) was 0.139 ml · kg−1 · min−1 (P = 0.780). Other physiological measures also were similar between conditions (P > 0.05). In conclusion, 5 days of quercetin supplementation did not influence [Vdot]O2max or related variables in sedentary men and women.