Effect of High Intensity Interval Training and Moderate Intensity Continuous Training on Electrocardiographic Indices in Sedentary Men

High Intensity Interval Training (HIIT) has higher intensity compared to traditional moderate intensity continuous training (MICT) protocols which seems to have different cardiorespiratory responses. Therefore, the aim of this study was to compare the effects of HIIT with MICT on cardiac electrocardiographic activity in sedentary male subjects.

16 sedentary male volunteers were randomized into HIIT (4-minute running bouts at 75-80% of the reserve heart rate with 3-minute active rest intervals) and MICT (30 minutes of running with at 45-60% of reserve heart rate) groups, ECG was recorded before and following to eight weeks of training in the same conditions. Independent t test and paired samples t test were used to analyze the data.

Both HIIT and MICT significantly increased P-R interval, T-wave duration, QRS complex duration, QT interval and R_R interval (p≤0.05). However, mean ST and QTc fragments had no changes in both training groups. However; the P wave duration was significantly elevated just in MICT group.

It seems that both HIIT and MICT lead to similar adaptations in cardiac ECG activity.