Assessment of Cardiac Autonomic Activity Before and After Isotonic Exercise Training (Treadmill Ergometer) in the Offsprings of Hypertensive Parents

It is accepted that genetics and the environmental factors play an important role in the genesis of hypertension. Parental history of hypertension increases the risk of developing hypertension at younger age. Isotonic exercise is an exercise that improves oxygen consumption by the body. Heart rate variability is a valuable research tool to study and investigate the cardiac autonomic activity. The present study was planned to assess the effect of isotonic exercise training (treadmill ergometer) on cardiac autonomic activity in the normotensive offsprings of hypertensive parents. A total of 50 normotensive subjects of age group between 18 to 26 years whose parents, either father or mother or both are hypertensive, were selected for the study. Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP) and HRV parameters were recorded before exercise (baseline) and after the completion of isotonic exercise training (treadmill ergometer) schedule of four successive days a week for three months according to the modified Bruce protocol. After exercise training, we observed a significant reduction in Heart Rate (beats per min.) and Systolic Blood Pressure (mmHg) where as a highly significant increase in High Frequency in power percentage as well as significant increase in High Frequency in normalized units in comparison with their basal parameters. Our results suggest that even a short duration of regular isotonic exercise training (treadmill ergometer) for four successive days a week for three months can improve vagal tone.