Ambulatory electrocardiographic findings in young athletes between 14 and 16 years of age

Abstract
Ambulatory electrocardiographic recordings were obtained from 35 male athletes between 14 and 16 years old, and from 35 male nonathlete controls of the same ages, in order to determine the effects of regular physical training on cardiac electrical activity. In the young athletes, the heart rates were significantly (PP<0-05). Ventricular premature beats were present in 60% of athletes and 57% of controls. The bradycardia in athletes did not predispose to ventricular ectopic activity, since heart rates at the times of occurrence of extrasystoles were higher in athletes than in controls. Even after two years of regular physical training there are significant differences in sinus nodal function and atrioventricular conduction as between young athletes and controls.