[Infectious diseases and physical activity].

Moderate physical activity has a beneficial effect on health. On the other hand, physical and psychological stress may have a suppressive effect on the immune system, implying that intense physical activity may possibly enhance the appearance of infectious diseases. There are no studies showing any effect on the immune system, nor on the frequency of infections, from physical training of low to moderate intensity. However, in several cases, high intensity training has been shown to produce chronic overtraining, which may impair general health. It is suggested that the extreme physical exertion of elite athletic training may suppress the immune system and thus lead to enhanced susceptibility to infectious diseases. Furthermore physical activity during the incubation period of several serious infectious diseases seems to be especially disadvantageous for the course of the disease.