Context: Yoga is an ancient science, which originated in India. Pranayama has been assigned a very important role in yogic system of exercises. It is known that regular practice of breathing exercises (pranayama) increases parasympathetic tone, decreases sympathetic activity, and improves cardiovascular functions. Different types of breathing exercises alter autonomic balance for good by either decrease in sympathetic or increase in parasympathetic activity. Mukh Bhastrika (yogic bellows), a type of pranayama breathing when practiced alone, has demonstrated increase in sympathetic activity and load on heart, but when practiced along with other types of pranayama has showed improved cardiac performance. Aim: The present study was conducted to evaluate the effect of long term practice of fast pranayama (Mukh Bhastrika) on autonomic balance on individuals with stable cardiac function. Settings and Design: This interventional study was conducted in the department of physiology. Materials and Methods: 50 healthy male subjects of 18 - 25 years age group, fulfilling the inclusion and exclusion criteria underwent Mukh Bhastrika training for 12 weeks. Cardiovascular autonomic reactivity tests were performed before and after the training. Statistical Analysis Used: The parameters were analyzed by Student t test. Results: This study showed an increase in parasympathetic activity i.e., reduced basal heart rate, increase in valsalva ratio and deep breathing difference in heart rate; and reduction in sympathetic activity i.e., reduction in fall of systolic blood pressure on posture variation. Conclusion: It can be concluded that Mukh Bhastrika has beneficial effect on cardiac autonomic reactivity, if practiced for a longer duration.
Key words: Cardiovascular autonomic reactivity, Mukh Bhastrika, valsalva ratio, yogic bellows.