The present special issue of Scandinavian Journal of Medicine & Science in Sports deals with health and fitness benefits of regular participation in small-sided football games. One review article and 13 original articles were the result of a 2-year multi-center study in Copenhagen and Zurich and include studies of different age groups analyzed from a physiological, medical, social and psychological perspective. The main groups investigated were middle-aged, former untrained, healthy men and women who were followed for up to 16 months. In addition, elderly, children and hypertensive patients were studied. A summary and interpretations of the main findings divided into an analysis of the physical demands during training of various groups and the effect of a period of training on performance, muscle adaptations and health profile follow. In addition, social and psychological effects on participation in recreational football are considered, the comparison of football training and endurance running is summarized and the effects of football practice on the elderly and children and youngsters are presented.