[Physical exercise, oxidative stress and damage].
Physical activities (aerobic, anaerobic and resistance exercises) evoke an increased production of high oxidative substances, depending mainly on the intensity of the muscle actions. Antioxidants in the muscle and blood represent the first line of defense, but an oxidative stress activates the scavenger enzyme systems. If the stress is too high, structural modifications, "damage" of lipids, proteins and nucleic acids is a consequence. Markers of this oxidative damage can be recognized for a few days. Oxidative stress certainly have a role in the physiological adaptation to the physical activity. Moderate intensity (less than 50-60% of the aerobic capacity or of the maximal muscle tension) exercises exert low stress without oxidative damage impulse in the normally nourished subjects. Regular training and "normal" diet results a proper defense against excess oxidative stress. Monitoring of the oxidative stress or/and damage is not jet a tool in the training praxis in spite of the obvious advantages and of the existence of certain noninvasive methods. Data reinforce the necessity of regular exercise with moderate intensity in the primary prevention and in the rehabilitation of metabolic and cardiovascular diseases.