Echocardiographic measurements were performed on fifteen football players, in moderate training and on untrained control groups. In comparison with the untrained subjects the echocardiographic tests displayed in athletes a 34% increase in the stroke volume, a 23% increase in the left cavity in diastole, a 11% increase in thickness of left wall in diastole, an increase of the area of the heart's transverse section and of the left miocardial volume. The contractility and pump indexes were the same for both groups of subjects. In conclusion, football is a compound type sport, implying mainly isotonic muscle contractions and isometric too; miocardial hypertrophy in football players' heart has a physiological character.