Physical training for patients with internal diseases differs in many points to the physical activity recommended for health maintenance. Cardiac patients are usually limited by symptoms (angina, ECG abnormalities, anaerobic threshold) therefore the intensity of the training (monitored by heart rate or ECG) must be setted by an ergometer exercise testing. Patients with obliterative peripheral artery disease may surpass the local anaerobic threshold during interval-type loads. Blood pressure limits the training intensity of the hypertensive patients if not an organ lesion. COPD patients use the rest periods of an interval training for expectoration and for restitution of their blood gas values. In insulin dependent diabetes the vascular complications can be avoided by a proper insulin regime, training and diet. Day-to-day training by an even energy need acts like the insulin therefore it must be carefully dosed. In NIDDM also the carbohydrate metabolism can improve significantly. In anxiety and depression the training and the social milieu offers a physiological trigger for the improvement. Other rehabilitative interactions (psychology, dietetics, behavioral modalities etc.) are built up in the basis of exercise training.