In summary, we have discussed the anatomical and physiologic effects of physical training and how they alter the physical examination, thoracic roentgenogram, ECG, and echocardiogram of the athlete. The importance of recognizing these deviations from "normal" findings is to avoid considering them evidence of cardiac disease. On the other hand, it is important to exclude cardiovascular disease in those pursuing vigorous athletics because of the potential for sudden cardiac death in those with coronary artery, valvular, or myocardial disease. Unfortunately, the first manifestation of coronary artery disease may be sudden death during athletic performance, a disease not easily detected in asymptomatic individuals. Finally, improper training, excessive trauma, and extreme environmental conditions may contribute to cardiovascular accidents in the competing athlete.