Electrocardiographic Changes Induced by Endurance Training and Pubertal Development in Male Children

Training-induced electrocardiographic changes are common in adult athletes. However, a few data are available on electrocardiogram (ECG) in preadolescent athletes and little is known about the potential changes induced by training on 12-lead electrocardiogram (ECG) at rest. Twelve-lead ECGs at rest and complete echocardiographic examinations were performed in 94 children (57 endurance athletes, 37 sedentary controls; mean age 10.8 ± 0.2 and 10.2 ± 0.2 years, respectively) at baseline and after 5 months of growth and training in athletes and of natural growth in controls. At baseline, athletes had lower heart rate at rest compared with controls (p = 0.046) and a further decrease was observed after training (p