The purpose of this double blind randomized clinical trial is to compare the effects of quercetin supplements, vitamin C and both Vit. C and quercetin composition on endothelial function, oxidative stress, athletic performance, indicators of inflammation and muscle damage in athletes. In this study, 60 athletes from the university student athletes who meet inclusion criteria are randomly assigned into one of the intervention or control groups. The participants in the intervention group will receive 500 mg of quercetin capsules a day or 25 mg of vitamin c or both and placebo groups will receive one capsule (containing lactose) daily for 8 weeks. Athletic performance, body mass index, SVCAM , PAI-1, SICAM-1، E-selectin CRP, traveled distance, time to exhaustion, heart rate, blood lactic acid, IL-1B, IL-2, IL-6, TNF-α, creatine kinase C, aspartate amino transfrase will be measured and compared forbetween the four groups.