The purpose of the present study was to investigate the effects of aerobic and anaerobic training on serum lipid peroxidation levels and on antioxidant enzyme activities. Long distance runners for aerobic training group, and wrestlers for anaerobic training group were chosen. Non-sporting men were used as control group. When the aerobic power was compared; indirect VO2max of long-distance runners were found higher than wrestlers and control group (p<0.001, p<0.001). When lipid peroxidation levels were compared; levels of the thiobarbituric acid reactive substances (TBARS) of long distance runners were found to be lower than those in the control group (p<0.05), but similar to those found in wrestlers. Comparison of antioxidant enzyme activities in erythrocytes show that there were no significant difference among the groups in superoxide dismutase enzyme activities, but glutathione peroxidase (GPx) activity of long distance runners was higher than that measured in wrestlers (p<0.05). These results suggest that aerobic training increased in erythrocytes GPx activity with a subsequent decrease in plasma TBARS levels but anaerobic training had no effect on this process.