[The importance of physical activity in the modern health concept].

Physical activity has increasingly become an integrated part of both the prevention and treatment of many diseases. This approach is based on data from large studies linking either physical activity or physical capacity to the incidence of disease. Furthermore, regular physical activity can influence health indirectly, since people who become physically active also tend to change other health-related habits in a positive direction. The author outlines some specific effects of exercise on certain diseases, and discusses the data indicating how much training is necessary to obtain the desired effects on health.