Comments on "Alternate Nostril Breathing at Different Rates and Its Influence on Heart Rate Variability in Non Practitioners of Yoga".

INTRODUCTION Heart rate variability is a measure of modulation in autonomic input to the heart and is one of the markers of autonomic functions. Though there are many studies on the long term influence of breathing on HRV (heart rate variability) there are only a few studies on the immediate effect of breathing especially alternate nostril breathing on HRV. This study focuses on the immediate effects of alternate nostril breathing and the influence of different breathing rates on HRV. MATERIALS AND METHODS The study was done on 25 subjects in the age group of 17-35 years. ECG and respiration were recorded before intervention and immediately after the subjects were asked to perform alternate nostril breathing for five minutes. RESULTS Low frequency (LF) which is a marker of sympathetic activity increased, high frequency (HF) which is a marker of parasympathetic activity decreased and their ratio LF/HF which is a marker of sympatho/vagal balance increased immediately after 6 and 12 minutes in comparison to baseline values whereas there was no significant difference in the means of these components when both 6 and 12 minutes were compared. CONCLUSION Immediate effects of alternate nostril breathing on HRV in non practitioners of yogic breathing are very different from the long term influence of yogic breathing on HRV which show a predominant parasympathetic influence on the heart.