Comparison of the Effect of Continuous and Interval Aerobic Training on Electrocardiogram of Active Young Girls

Aims Few studies have examined the effects of various models of aerobic training on electrocardiogram (ECG). The purpose of this study was to compare the effect of continuous and interval aerobic training on ECG of active young girls.  Methods & Materials The research method was quasi-experimental and 30 active young girls were selected from among physical education students (age=17.0±0.4 yr) and were randomly asPned to three groups of continuous aerobic training, interval aerobic training and control (each group was 10). The protocol of the trainings (eight weeks, three sessions per week) included 20-35 minutes of running per session, with an intensity of 60-75% of the maximum heart rate. Before and after the training, general characteristics of subjects were measured and their ECGs were recorded. To analyze the data, analysis of variance with repeated measurements was used at the Pnificant level of P<0.05.  Findings Eight-week continuous and interval aerobic training had no Pnificant effect on amplitudes of P, R, and T waves, PR interval and duration of ST segment (P>0.05), whereas both types of training similarly increased QT interval (continuous: P=0.001, interval: P=0.027) and reduced heart rate (continuous: P=0.002, interval: P=0.013). Only in the interval training group RR interval showed a Pnificant increase (continuous: P=0.079, interval: P=0.007). Conclusion Eight weeks of continuous and interval aerobic training appears to similarly decrease heart rate and increase QT interval in active young girls, whereas only interval aerobic training results in increased RR interval.