Shirley Telles,* Nagarathna R., and Nagendra H. R.
Vivekananda Kendra Yoga Research Foundation,
No. 9 Appajappa Agrahara. Chamarajpet, Bangalore - 560 018
(Received on July 15, 1993)
Abstract : There is increasing interest in the fact that breathing exclusively through one nostril may alter the autonomic functions. The present study aimed at checking whether such changes actually do occur, and whether breathing is consciously regulated. 48 male subjects, with ages ranging from 25 to 48 years were randomly assigned to different groups. Each group was asked to practice one out of three pranayamas (viz. right nostril breathing, left nostril breathing or alternate nostril breathing). These practices were carried out as 27 respiratory cycles, repeated 4 times a day for one month. Parameters were assessed at the beginning and end of the month, but not during the practice. The ‘right nostril pranayama’ group showed a significant increase, of 37% in baseline oxygen consumption. The ‘alternate nostril pranayam’ a group showed an 18% increase, and the left nostril pranayama group also showed an increase, of 24%. This increase in metabolism could be due to increased sympathetic discharge to the adrenal medulla. The ‘left nostril pranayama’ group showed an increase in volar galvanic skin resistance, interpreted as a reduction in sympathetic nervous system activity supplying the sweat glands. These results suggest that breathing selectively through either nostril could have a marked activating effect or a relaxing effect on the sympathetic nervous system. The therapeutic implications of being able to alter metabolism by changing the breathing pattern have been mentioned.
Key words: yogic breathing; unilateral nostril breathing; oxygen comsumption; automic function.
The nasal cycle is an ultradian rhythm during which the patency and functional efficiency of the right and left nares changes alternately with an average periodicity of about 2 to 3 hours when awake (1,2). The link between the sympathetic and parasympathetic divisions of the autonomic nervous system and the nasal cycle, has been worked out by experiments on humans (2,3) and in non-human species, as well (4). Whether breathing through a particular nostril could selectively activate either division of the autonomic nervous system, has been tested by studying the effects of forced unilateral nostril breathing on autonomic activities. Werntz and colleagues (5) correlated right nostril dominance with the ‘activity phase’ of the basic rest activity cycle. This has been validated by the work of Backon (6) which showed that forced right nostril breathing significantly increases blood glucose levels, whereas left nostril breathing lowers it.
The ancient Indian science of Yoga makes use of voluntary regulation of the breathing to make respiration rhythmic, and to calm the mind. This practice is called Pranayama. Some varieties of Pranayama require the practitioner to inhale and exhale through one nostril selectively. These Yogic practices provide an opportunity to study the effects of selective nostril breathing carried on effortlessly for prolonged periods. When each respiratory cycle is completed through the right nostril excusively, the practice is called Surya Anuloma Viloma Pranayama, which means ‘heat generating breathing practice’, and when completed through the left nostril alone, the practice is called Chandra Anuloma Viloma pranayama, which means a ‘heat dissipating or cooling breathing practice’. In Nadisuddhi Pranayama (which means ‘purification of subtle energy paths’), inhalation and exhalation are through alternate nostrils for successive respiratory cycles. These names were given based on the subjective experiences of the ancient sages.
The present Study has been carried out to assess whether practising any one of the three Pranayamas described above, for a month, would cause changes in baseline metabolic and autonomic activities.