Symmetric enlargement of the heart begins when endurance training exceeds individual functional
limits, resulting in both left and right ventricular and atrial hypertrophy in response to the increased
workload placed on the heart. Routinely examined by echocardiography, the myocardial hypertrophy is
related to the increase in the interior end-diastolic volume. In contrast to pathological forms of cardiac
wall hypertrophy, the mass/volume ratio, and therefore the maximum systolic wall stress remains
constant. In addition, functional and structural changes occur in the vascular system.