Effects of yoga and supervised integrated exercise on heart rate variability and blood pressure in hypertensive patients

Objective: Heart rate variability (HRV) is a marker of cardiovascular autonomic status. The autonomic status has a relationship with cardiovascular disorders and physical as well as mental activities. Determination of HRV is used as a technique to assess the autonomic control of heart. The objective of this study was to study the effects of yoga and supervised integrated exercise on HRV and blood pressure in hypertensive patients. Methods: The study group consisted of 47 moderately hypertensive patients, divided into 3 experimental groups (viz. 16 in yoga group, 16 in exercise group and 15 yoga + exercise group) and 31 normal controls. The three groups underwent yoga, exercise, both yoga and exercise together respectively for 9 months. The time domain HRV during deep breathing and blood pressure were measured at 0,3,6, and 9 months in all the groups. Results: A significant improvement of HRV was found during the entire duration of exercise (12.29 ± 1.75 vs 15.64 ± 1.72 at 9 months P < 0.001). No significant change in HRV was found in yoga group at the end of 9 months. Supervised integrated exercise + yoga for 9 months showed a significant HRV improvement in this group (15.41 ± 2.06 at 6 months vs 17 ± 2.06 at 9 months P < 0.001). The systolic blood pressure (SBP) and diastolic blood pressure (DBP) in these hypertensive patients corrected towards normalcy in different groups, except in yoga group. There was no significant effect on HRV and BP in control group in the intervening period. Conclusion: Supervised integrated exercise improves HRV and BP significantly in hypertensive subjects. Yoga does not cause any significant change in HRV and SBP. Yoga combined with regulated exercise was found be very effective in improving HRV and reducing BP.