Competitive sport causes physiological changes called athlete’s heart. In most cases echocardiographic parameters return to normal after cessation of career. Sudden cardiac death may occur in persons with previously diagnosed or undiagnosed heart disease. Mortality is 1-3 people/100,000. The main reasons for death is hypertrophic cardiomyopathy and commotio cordis. In cardiomyopathy coronary vasculature does not increase proportionately to heart mass. In the case of extreme physical effort areas of poor blood supply can cause dangerous arrhythmias. Commotio cordis is caused by by blunt trauma to the thorax, which induces ventricular fibrillation and cardiac arrest without structural damage.