Resting electrocardiogram and blood pressure in young athletes and nonathletes: a 4-year follow-up

Abstract

A follow‐up data on electrocardiogram (ECG) and blood pressure (BP) changes in adolescent athletes are scarce. We compared ECG and BP between adolescent athletes and nonathletes in a 4‐year follow‐up. A total of 154 youth sports clubs (SC) in Finland and 100 secondary schools for comparison data participated in this observational follow‐up study. Those who maintained or adopted SC participation are referred to as ‘Always athletes’ (n = 137), those who never participated in SC as ‘Never athletes’ (n = 108) and those who dropped out ofSC during the follow‐up as ‘Changers’ (n = 116). The mean age of the participants was 15.5 (0.6) years in all study groups at baseline. Resting ECG including heart rate, PR interval, QRS duration, QRS axis, QRS amplitude, T axis and QT interval and BP were measured from all participants at baseline and after follow‐up. ‘Always athletes’ had lower resting heart rate, more negative T‐wave axis and higher QRS amplitude than ‘Never athletes’ at baseline and at 4 years (p < 0.05). ‘Changers’ had lower resting heart rate, more negative T‐wave axis and higher QRS amplitude, systolic BP and pulse pressure than ‘Never athletes’ at baseline (p < 0.05). None of the observed differences at baseline, were visible at 4 years (p > 0.05) except the difference in T‐wave axis (p = 0.028). The significant group × time interaction between ‘Changers’ and ‘Never athletes’ was found for QRS amplitude (p = 0.017). Adolescent athletes have several training‐induced cardiovascular adaptations, which return towards the levels of nonathletes after cessation of regular training.