Influence of alternate nostril breathing on cardiorespiratory and autonomic functions in healthy young adults.

Alternate nostril breathing (ANB) may modulate cardio-respiratory and autonomic functions. However, the studies are scarce and results highly conflicting. The present study was conducted in healthy young volunteers comprising of males (n=20) and females (n=20) in range of 17-22 years. In both groups respiratory rate (RR/min), heart rate (HR/ min), systolic blood pressure (SBP; mm Hg), diastolic blood pressure (DBP; mm Hg), peak expiratory flow rate (PEFR; L/min) and galvanic skin resistance (GSR; microV) were recorded thrice; once as control and then after 15 min (acute exposure) and following 8 wks of training in ANB (15 min daily). In males the control RR was 16.60 +/- 2.01, HR 75.75 +/- 11.07, SBP-115.9 +/- 7.33, DBP 70.4 +/- 6.28 and PEFR 550.00 +/- 51.50. After 15 min of ANB-RR (14.75 +/- 1.41, P<0.001), HR (68.45 +/- 12.41, P<0.01) and SBP (113.6 +/- 6.04, P<0.05) fell significantly. After 8 wks of ANB training RR (12.35 +/- 1.35, P<0.0001), HR (63.20 +/- 11.11, P<0.001), SBP (109.5 +/- 5.61, P<0.001), declined to much greater extent and PEFR (571.50 +/- 46.26, P<0.01) rose significantly. In females the control RR was 17.25 +/- 1.89, HR-74.90 +/- 12.85, SBP-106.70 +/- 6.91, DBP-68.70 +/- 5.52 and PEFR-394.50 +/- 44.89. After 15 min of ANB RR (15.05 +/- 1.54, P<0.001) and HR (64.75 +/- 9.80, P<0.001) showed significant decline with concomitant rise in PEFR (407.00 +/- 2.31, P<0.05). Following 8 wks training the decrement in RR (12.60 +/-1.50, P<0.0001) and HR (63.30 +/- 8.65, P<0.001) was maintained. SBP (103.10 +/- 4.92, P<0.001) and DBP (65.8 +/- 5.54, P<0.001) decreased further and PEFR (421.00 +/- 38.51 P<0.001) rose, GSR was unaffected by ANB in both males and females. These results suggest that in general there is a tilt towards parasympathetic dominance by alternate nostril breathing. This breathing may be a useful adjuvant to medical therapy of hypertension and COPD.