EXERCISE AND RESISTANCE TO INFECTION

Epidemiological data suggest that endurance athletes are at increased risk for upper respiratory tract infection (URTI) during periods of he avy training and the 1- to 2-week period following race events. Modera te exercise training has been associated with a reduction in incidence of URTI. There is growing evidence that for several hours subsequent to heavy exertion, several components of both the innate (e.g., natura l killer cell activity and neutrophil oxidative burst activity) and ad aptive (e.g., T and B cell function) immune system exhibit suppressed function. The immune response to heavy exertion is transient, and furt her research on the mechanisms underlying the immune response to prolo nged and intensive endurance exercise is necessary before meaningful c linical applications can be drawn. Some attempts have been made throug h chemical or nutritional means (e.g., indomethacin, glutamine, vitami n C, and carbohydrate supplementation) to attenuate immune changes fol lowing intensive exercise to lower the risk of infection.