Department of exercise physiology, faculty of physical education and sport sciences, university of Guilin, Rasht, Iran
چکیده
There are some epidemiological studies suggestive that an increase in risk of different diseases in athletes who over train or participate in extremely demanding exercise bouts. Despite the anecdotal appeal of an association between extreme exertion and increased risk of infection, there are no controlled clinical trials to test this in a systematic and methodologically rigorous fashion. Moreover although there are studies linking exercise with immune function, causal interference to infectious disease has not been demonstrated. While it is comparatively easy to show experimentally an augmentation or suppression of immune responses to exercise, it has been more difficult to establish clinical relevance. Part of the difficulty in evaluating is caused nature of exercise-induced changes in immune parameters with risk for infection is due to methodological limitations in measuring physical activity and fitness in large populations, the factor of clustering of positive health behavior (such as the absence of tobacco used by athletes), and multifactorial etiology of chronic disease including those with an immunological component.
