Energy expenditure and ventilatory responses during Virasana
Indian Journal of Physiology and Pharmacology.
Rai L, Ram K.
Department of Physiology, Central Research Institute for Yoga, New Delhi.
Energy expenditure and ventilatory responses to yogic standing posture of Virasana were studied on 10 healthy men (25-37 years of age).
The results of various responses respectively to the horizontal supine, Chair-sitting and Virasana were:
Minute Ventilation (VE) 7.64, 8.61 and 18.67 L/min; Respiratory Frequency (FR) 15.71, 15.70 and 21.45 Breath/min; Tidal Volume (VT) 0.496, 0.544 and 0.827 L/min; Oxygen consumption (VO2) 0.127, 0.234 and 0.573 L/min; Carbondioxide Elimination (VCO2) 0.127, 0.134 and 0.420 L/min; Respiratory Exchange Ratio (RER) 0.58, 0.57 and 0.69; Heart Frequency (FH) 65.2, 74.5 and 104.4 beats/min; Oxygen Pulse (O2P) 3.32, 3.17 and 5.45 ml/beat; Ventilatory Equivalent (VE-EQ) 36.78, 37.12 and 33.85; Multiple of Resting VO2 (METS) 0.96, 1.05 and 2.53 and Metabolic Cost (MC) 1.04, 1.13 and 2.76 Cal/min. Virasana posture was characterised by higher VE, FR, VT, VO2, VCO2, FH and O2P with lesser VE-EQ. The observations suggest that Virasana induces temporarily a hypermetabolic state characterised by enhanced sympathetic nervous system activity which gets inhibited during the adoption of resting supine shavasana posture.