Infection and the elite athlete: a review.

Light to moderate exercise has been associated with an increase in immune function and reduced risk of infectious diseases. Conversely, heavy exercise has been implicated in suppression of many immune parameters and a concomitant increased risk of infectious diseases. Infections can result in lost training time and negatively affect the performance of the elite athlete. Exercising during an infection can also increase the risk of secondary complications, such as viral myocarditis and post-viral fatigue syndrome. In addition to immunosuppression, other factors responsible for increased infection rates among athletes are close bodily contact with other people during training and competition, and environmental factors during the pursuit of sporting activities that increase exposure to pathogens. Although there is a generally higher risk of infection among athletes compared to the general population, some sports are associated with a particularly high risk for certain infections. These are skin infections in rugby and wrestling, infections of the foot in long-distance runners, and ear infections in those involved in water sports. Upper respiratory tract infections are the most frequently reported disability among all athletes and are the cause of more lost training days than all other infections put together. Transmission of blood-borne pathogens, although very uncommon in the athletic setting, are the cause of the most serious infections an athlete may develop. When considering the negative impact of infections on performance, it seems prudent that athletes use interventions to decrease the immunosuppressive effects of heavy exercise, and to minimize exposure to pathogens as far as practically possible. Management of the infected athlete is especially important if there is to be a speedy return to full training, and if the incidence of a relapse or secondary complications are to be minimized.