ABSTRACT
Several types of infectious diseases affect athletes, often because they perform in an environment in which certain pathogenic microorganisms are particularly widespread, or, due to the type of sport, abrasions or other tissue injuries are more likely. Many athletes feel that while their regular training programs promote resistance to respiratory tract infections, the actual competitive event increases their risk. Psychological factors may also play an important role in the relationship between exercise and respiratory infection. Exercise is a form of physiological stress, varying according to the intensity and duration of the training program. In particular, exercise-induced elevations in plasma catecholamines and glucocorticoids are of interest, because these hormones have been shown to effect immune function. The acute response of the immune system to psychological stressors is, in many ways, similar to those that occur in response to acute exercise.
