[Play sports and feel well! Effects of sports on mental health].

The role of mental health is increasingly recognised in the discussion about health. In this article, health is considered to be a dynamic balance between resources and potential risk factors. Sport and physical activity may represent resources that do not only contribute to an increased well-being, but also to an improved self concept as a cognitive representation of one's health-status. Investigations of the short-time effects of sport show that different activities result in different mood changes, but also that the initial mood is important in such a way that people with a bad mood profit more from physical activity programmes. More permanent physical activity results in better well-being, but also in an improved perception of the health status and a higher satisfaction with health. Individually tailored new physical activity behaviour programmes and reinforcing systems have to be developed. These may lead to adequately strengthen the self-efficacy and increase the well-being of a broader population.