A single session of resistance exercise induces oxidative damage in untrained men

PURPOSE:: During exercise, the production of reactive oxygen and nitrogen species significantly increases. The aim of the present study was to investigate the effects of a single session of resistance exercise on antioxidant capacity, oxidative damage, and inflammation. METHODS:: Muscle biopsies, urine, and blood samples were collected from seven healthy men before and after a single bout of resistance exercise. RESULTS:: A single session of resistance exercise was found to induce oxidative damage, as shown by a 40% increase in the concentration of urinary F2alpha-isoprostanes (P < 0.05). Total antioxidant capacity of plasma increased 16% (P < 0.05). This increase seemed to be predominantly attributable to an increase in plasma uric acid concentrations of 53% (P < 0.05). Similar to uric acid, but to a relatively much smaller extent, vitamin C and vitamin E levels in plasma were also elevated (P < 0.05). Moreover, the erythrocyte glutathione (glutathione reductase) concentration increased 47% during exercise (P < 0.05). Also in skeletal muscle, uric acid levels were found to increase after exercise (P < 0.05). Moreover, 30 min after exercise, skeletal muscle glutathione S-transferase (GST) and glutathione reductase activity increased 28 and 42%, respectively (P < 0.05). Skeletal muscle reduced glutathione reductase and glutathione reductase disulphide (GSSG) concentrations were not affected by exercise. The Nuclear Factor kappa B (NF-kappaB) activity in peripheral blood mononuclear cells (PBMC) was not increased by exercise, indicating that a NF-kappaB-mediated inflammatory response does not occur. CONCLUSION:: We conclude that a single session of resistance exercise induces oxidative damage despite an adaptive increase in antioxidant capacity of blood and skeletal muscle.