Both cigarette smoking and strenuous exercise are associated with increased oxidative stress. Therefore, we aimed to investigate the effects of strenuous anaerobic exercise on oxidative stress, assessed with 8-hydroxydeoxyguanosine (8-OHdG), in cigarette smokers and nonsmokers. Healthy male smokers (n=13) and nonsmokers (n=12) participated in this study. Each participant performed a graded treadmill exercise test to determine maximal oxygen consumption (VO2max), and the Wingate anaerobic test as a strenuous exercise. Blood samples were obtained before and on completion of the test, and then again at 60 min after the test. There were no statistically significant differences in exercise performance values (VO2max, peak power, average power) between the two groups (p>0.05). Blood lactate concentration increased significantly in both groups (p<0.001); however, no significant smoking status (p>0.05) or smoking status over time interaction (p>0.05) was observed for blood lactate. Level of 8-OHdG increased in both groups; significant main effect of exercise (times effects) were noted (p<0.001) for 8-OHdG, with higher values for smokers. Therefore, no significant smoking status (p>0.05) or smoking status over time interaction (p>0.05) was found for 8-OHdG. Consequently, strenuous anaerobic exercise exacerbated the oxidative stress damage evaluated by 8-OHdG, both in cigarette smokers and nonsmokers. Results indicated that an inactive lifestyle is as harmful as smoking itself.