ABSTRACT
Responses of an antioxidant system are dependent on the type, mode, intensity, frequency, and duration of exercise, animal species, tissue specificity, and the extent of exposure to drugs and chemicals. Oxidative stress (physical and/or chemical) can be described as a disturbance in the antioxidant system that is not able to adequately scavenge free radicals/reactive oxygen species and arrest lipid peroxidation chain reactions. However, several metabolic pathways could form electrophilic intermediate metabolites and generate superoxide and free radicals. Exercise training can provide protection to the heart against oxidative damage via ascorbate ion and vitamin E. Hepatic total glutathione level was elevated in the trained rats; however, the single bout of exercise decreased muscle and liver total glutathione level. The status of the antioxidant enzymes varies after acute exercise and exercise training in different tissues in various animals and humans. With more knowledge of the intracellular regulation of the antioxidant system, pharmacological intervention may be plausible against oxidative tissue damage.
