Oxidants in Daily Life and Common Health Conditions

Exercise
Since oxidants are generated as a byproduct of body�s metabolism, their formation increases as the body�s metabolism increases. In actively respiring mitochondria, up to 4 % of the oxygen consumed by the mitochondria is turned into superoxide radicals, more than enough to kill a cell unless the free radicals are quickly disposed of. Although our body is equipped with an elaborate antioxidant defense system, a long physical exertion can tip the oxidant-antioxidant balance toward oxidative stress. Regular exercises, however, increase the concentration of superoxide dismutase, an antioxidant enzyme, within muscle cells, enhancing body�s sport endurance.