The benefits of physical activity, both for prevention and therapy of cardiovascular diseases, have been clearly proven. Therefore, before starting a training program, especially in cases with a cardiovascular risk profile and cardiac diseases, a risk stratification and detailed cardiological examinations are recommended. Depending on the underlying pathology, specific training recommendations should routinely be prescribed as part of the therapy. Since exercise can also be a trigger for sudden cardiac death, athletes and competitive sportsmen undergo annual screening examinations to identify athletes with increased risk or asymptomatic disease. Physiological adaptations in the sense of an athlete’s heart, are observed in endurance athletes. However, such structural changes can also represent a gray area and should therefore be evaluated differentially in the context of all collected findings.