Exercise Training and Immunosenescence

During the aging process, a decrease in the ability of the immune system to control infection, known as immunosenescence, takes place. Paradoxically, aging also results in chronic low-level inflammation and exaggerated inflammatory responses. A number of studies have investigated the effects of a variety of exercise training interventions on the immune system both in humans and using animal models of aging. Cross-sectional studies that compared masters athletes to untrained, age-matched controls found that the athletes had significantly better immune function, but these studies suffered because of the difficulty in generalizing results from highly trained athletes to a general population of physically active older adults. Prospective studies in humans have attempted to address this, but these studies have resulted in sometimes equivocal findings, possibly as a result of the differences in exercise training programs used. Finally, animal studies, both observational and mechanistic, have almost universally supported the exercise effect on enhancing immune status in the aged. More research is needed to determine the mechanism by which exercise influences immunity in the aged and to identify exercise training programs for use in this population. It is clear, however, that exercise is likely to be effective at boosting immunity in the older people when undertaken regularly.