Consumption of plant flavonoids, antioxidants, and n-3 fatty acids is proposed 
to have many potential health benefits derived primarily through antioxidant and 
anti-inflammatory activities. This study examined the effects of 1,000 mg 
quercetin + 1,000 mg vitamin C (QC); 1,000 mg quercetin, 1,000 mg vitamin C, 400 
mg isoquercetin, 30 mg epigallocatechin gallate, and 400 mg n-3 fatty acids 
(QFO); or placebo (P), taken each day for 2 wk before and during 3 d of cycling 
at 57% W(max) for 3 hr, on plasma antioxidant capacity (ferricreducing ability 
of plasma [FRAP], oxygen-radical absorbance capacity [ORAC]), plasma oxidative 
stress (F(2)-isoprostanes), and plasma quercetin and vitamin C levels. 
Thirty-nine athletes were recruited and randomized to QC, QFO, or P. Blood was 
collected at baseline, after 2 wk supplementation, immediately postexercise, and 
14 hr postexercise. Statistical design used a 3 (groups) × 4 (times) 
repeated-measures ANOVA with post hoc analyses. Plasma quercetin was 
significantly elevated in QC and QFO compared with P. Plasma F(2)-isoprostanes, 
FRAP, and vitamin C were significantly elevated and ORAC significantly decreased 
immediately postexercise, but no difference was noted in the overall pattern of 
change. Post hoc analyses revealed that the QC and QFO groups did not exhibit a 
significant increase in F(2)-isoprostanes from baseline to immediately 
postexercise compared with P. This study indicates that combining flavonoids and 
antioxidants with n-3 fatty acids is effective in reducing the immediate 
postexercise increase in F(2)-isoprostanes. Moreover, this effect occurs 
independently of changes in plasma antioxidant capacity.