MadSci Network: General Biology |
Shishir, You've posed an interesting question. I'm going to answer in two parts, one part addressing generalized breathing, the other the yogic practice of nadi shodhana, or conscious alternate-nostril breathing. A search through literature and the Web for naturally-occurring alternate- nostril breathing yielded almost nothing. Many web sites promoting nadi shodhana breathing mention medical literature that shows nostrils alternate with one another on natural two- to three-hour cycles; that is, during breathing one nostril will be dominant for a period of time and then gradually the other will become dominant, back and forth over the course of the day. However, I was unable to find any papers addressing this phenomenon in any citation database I searched. Disappointed, I went ahead and set up a random routine over the course of a couple of days where I made a rough measurement of air volume through each nostril while I exhaled. This is not a conclusive experiment, but the differences between the two nostrils were within the expected error in my measurements, and any measured differences between the two was consistently in favor of the same nostril. Turning to the practice of nadi shodhana was far more fruitful. This is an area of research which has been ongoing for at least the last eight years, mostly (though not exclusively) in India. One source listing the titles of research papers on the subject, including physiological and mental effects of alternate-nostril breathing, may be found at the web site of the Swami Vivekananda Yoga Research Foundation in Bangalore. The site address is http://www.vkyogas.org.in/re search.html . Further citations may be found by visiting the US National Library of Medicine at http://www.ncbi.nlm.ni h.gov/entrez/query.fcgi and searching for more papers by the authors listed at the Swami Vivekenanda site. I found more than forty citations of papers dealing with breathing practices and their physiological effects. I hope this is helpful!
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