Regular physical exercise has many beneficial effects, but it has been reported that strenuous exercise could elevate the production of free radical and other reactive oxygen species (ROS) which eventually injure the tissues and decrease the muscle function.So many kinds of antioxidant supplementations have been tried to decrease the muscle fatigue and enhance the exercise performance. polyphenolic flavonoids abundant in fruits and leafy vegetables have strong antioxidant effect. oligomerized litchi fruit extract has strong antioxidant capacity and higher bioavailability compared to that of grape seed polyphenol. The aim of this study was to determine whether oligomerized litchi fruit extract could induce endurance exercise performance more than Vit C + Vit E mixture or placebo could do. Therefore, we designed double blind randomized controlled trial, setting the change of running time to exhaustion under submaximal treadmill test as the primary endpoint.