Disuse and aging.

A review of biologic changes commonly attributed to the process of aging demonstrates the close similarity of most of these to changes subsequent to a period of enforced physical inactivity. The coincidence of these changes from the subcellular to the whole-body level of organization, and across a wide range of body systems, prompts the suggestion that at least a portion of the changes that are commonly attributed to aging is in reality caused by disuse and, as such, is subject to correction. There is no drug in current or prospective use that holds as much promise for sustained health as a lifetime program of physical exercise.