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

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.

Muscle biopsies, urine, and blood samples were collected from seven healthy men before and after a single bout of resistance exercise.

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 (GSH) [corrected] 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 GSH [corrected] and GSH [corrected] 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.

We conclude that a single session of resistance exercise induces oxidative damage despite an adaptive increase in antioxidant capacity of blood and skeletal muscle.