Metabolic response to exercise and muscle disease.

Physical fitness through exercise is the rage of today. Almost everybody is indulging in various forms of exercise from weight lifting to marathons. These regimens presuppose a normal muscle metabolism. However, a significant number of so-called normals end up with the symptoms of cramps, fatigue, and, in advanced cases, myoglobinuria. Exercise forms the mainstay of rehabilitation of patients with neurologic disorders manifesting as paresis or paralysis, and certain rheumatologic or metabolic problems are also handled via the medium of exercise therapy. It is, thus, imperative that there should be a clear understanding of normal muscle composition and metabolic responses. We will summarize the histology, histochemistry, physiology and metabolic responses of normal muscle to exercise and put this information in perspective in the light of various muscle disorders.