Evidence based data of physical activity in primary prevention of coronary heart disease are excellent. For secondary prevention these data still are acceptable. Although it is an important new target group for physical therapy, there are so far no favourable data for exclusive training therapy in children or adolescents presenting a syndrome of obesity, sedentary lifestyle and bad nutrition. In nearly all the studies in this field physical activity is integrated in nutrition counselling and behavioural therapy. The following recommendations for public health can be made: Each adult should exercise at least half an hour and each child or adolescent one hour a day. Physical activity is the logical response to the sedentary lifestyle and hyper caloric food intake which are continuously spreading all over the world since 3 decades. It is an excellent therapy with nearly no side effects.