Physical activity plays an important role in the maintenance of functions and the milieu interieur. There are many types and intensities of physical activity and their impact on the organism and its parts is varied. However, exercise must always be consistent with the state of the organism at a given moment. Inadequacy of the form and type of physical activity becomes always manifest after different time intervals, as a process of maladaptation and finally as a pathological adaptation. It is important for every age group and every health status but differs markedly as regards quality and quantity. Objective evaluation of the load and state of the organism and capacity of a physiological response is one of the basic principles of prevention as well as therapy.