The aim of this study was to investigate the effect of vitamin E treatment on increased oxidative stress in rats exposed to a swimming exercise protocol. In order to examine the effects of physical swimming training on the antioxidant defences of tissues and on their susceptibility to damage induced by exercise, the levels of glutathione (GSH) and thiobarbituric acid reacting substances (TBARS) levels, on indicator of lipid peroxidation in various tissues, have been determined. In this study, four groups of female rats were used while the rats were trained to swim for 30 minutes a day and five days a week which lasted eight weeks and vitamin E (vit. E) supplementation (30 mg/kg/day) has been carried out for five days a week. TBARS levels are significantly found lower in both trained and sedentary vit. E supplemented groups, since vit. E is the most important antioxidant in an earlier line of defence in lipid peroxidation. Also, in vit. E supplemented trained rats, the glutathione response is observed to be significantly higher, supporting with the TBARS levels and in accordance with the literature. But in the sedentary group without vit. E supplementation, the GSH levels of the liver and the heart tissues were significantly lower than both vit. E supplemented sedentary and trained groups. These results evaluate that vit. E confers protection to GSH levels in these tissues where the GSH levels were found significantly lower in the groups not supplemented with vit. E.