Effect of static and dynamic exercise on heart volume, contractility, and left ventricular dimensions.

Echocardiographic measurements in 90 successful athletes were compared with data from untrained subjects and patients with hypertension and cardiomyopathy. The athletes represented sports disciplines requiring predominantly static exercise and power training (weight lifters, hammer-throwers, shot putters) and dynamic or endurance exercise (middle and long distance runners, cyclists, nordic skiers, rowers). The left ventricular end-diastolic diameter in well-trained endurance athletes was increased from the normal mean of 47.8 to 53.6 mm. The relationship of ventricular wall thickness to end-diastolic diameter was not affected. With static training, an increase of the end-diastolic diameter in relation to body weight did not occur, but there was a definite increase of septal and posterior wall thickness with an altered ratio between end-diastolic diameter and wall thickness. The ratio stroke volume:heart volume was increased in endurance athletes, but decreased in power athletes. The shortening fraction was not altered by these various forms of training. The ejection fraction was increased in endurance athletes whereas power-trained athletes showed a moderate decrease. There was no indication of myocardial damage in power- or endurance-trained athletes. The critical threshold that is associated with damage is apparently not exceeded during athletic training.