This study investigated the effect of physical training and oxidative stress on the anti oxidative activity and on plasma lipid profile. Forty eight rats were given either a physical training or no training for 4 weeks and were then subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). The antioxidative activity was evaluated with the activities of catalase in plasma and superoxide dismutase (SOD), the ratio of reduced glutathione/ oxidized glutathione (GSH/GSSG) and the level of malondialdehyde (MDA) in liver. The plasma concentrations of triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C)) were also compared. Compared to those of non-training group. catalase activities of training group were lower before exercise but higher during and after exercise. SOD activities were higher regardless of exercise. GSH/GSSG ratio was higher before exercise but was not significantly different during exercise and even lower after exercise. There were no differences between non-training group and training group in MDA levels regardless of exercise. Compared to those of non-training group, atherosclerotic index of training group was lower after exercise and there were no significant differences before and during exercise. There were no differences between non-training group and training group in HDL-C regardless of exercise. These results suggest that moderate physical training can activate antioxidant defenses and decrease the atherosclerotic index and this beneficial effect is evident under exercise-induced oxidative stress.