Relationship between physical activity and oxidative stress biomarkers in women

between physical activity and levels of plasma lipid peroxides, superoxide dismutase in erythrocytes (SOD), and glutathione peroxidase (GSH-Px) in whole blood activities. Methods: Cross-sectional study in 488 Spanish women. Two categories of leisure time physical activity were defined according to their intensity: low (6 METs) and high (6 METs). Energy expenditure in household activities was also recorded. Multivariate linear regression analyses were used to adjust for the effect of physical activity on lipid peroxides and SOD and GSH-Px for confounding variables. Results: The amount of leisure time physical activity was associated with high activity levels of SOD (P 0.022) and GSH-Px (P 0.002). Similar results were obtained when physical activity in household activities was added to total leisure physical activity. Physical activity of low intensity was associated with high SOD activity levels (P 0.002) and that of high intensity with high GSH-Px activity levels (P 0.001). Conclusion: The amount and intensity of leisure physical activity were directly related to both antioxidant enzyme activity levels. The findings of this study suggest a modulatory effect of leisure physical activity intensity on antioxidative balance in the studied female population. Key Words: EXERCISE, LIPID PEROXIDES, SUPEROXIDE DISMUTASE, GLUTATHIONE PEROXIDASE. Oxidative stress produced by free radicals has beenlinked to the development of several diseases, suchas atherosclerosis, cancer, and neurodegenerative diseases (22,32). These free radicals include superoxide anion, hydroxyl radical, hydrogen peroxide, hypochlorous acid, and peroxynitrites (10). The biological oxidative ef