Free radicals in exhaustive physical exercise: Mechanism of production, and protection by antioxidants

Moderate exercise is a healthy practice. However exhaustive exercise genera tes free radicals. This can be evidenced by increases in lipid peroxidation , glutathione oxidation, and oxidative protein damage, It is well known tha t activity of cytosolic enzymes in blood plasma is increased after exhausti ve exercise. This may be taken as a sign of damage to muscle cells. The deg ree of oxidative stress and of muscle damage does not depend on the absolut e intensity of exercise but on the degree of exhaustion of the person who p erforms exercise. Training partially prevents free radical-formation in exh austive exercise. Treatment with antioxidants such as vitamins C or E prote cts in part against free radical-mediated damage in exercise, Xanthine oxid ase is involved in free-radical formation in exercise in humans and inhibit ion of this enzyme with allopurinol decreases oxidative stress and muscle d amage associated with exhaustive exercise. Knowledge of the mechanism of fr ee-radical formation in exercise is important because it will be useful to prevent oxidative stress and damage associated with exhaustive physical act ivity.