Excerpt from the KRI newsletter.
By Nikhil Ramburn and Sat Bir Singh Khalsa, Ph.D.
The most common breathing practice in yoga is long, slow, deep breathing. The diaphragm and lungs expand more fully with each breath. Yogic breathing involves the noticeable movement of the abdomen, which extends outwards on each inhale, thereby earning it the name of abdominal or belly breathing.
The deeper expansion of the lungs in simple, long, slow, yogic breathing effectively increases the lung surface available for gas exchange and so it is more efficient use of the lungs. The resulting increase in efficiency is equivalent to one possessing a larger lung.
Unfortunately, the understanding of the accurate benefits of yogic breathing is often compromised by misconceptions. The most common of these is the notion that slow, yogic breathing increases oxygen in the blood and that most of the public, who are not privy to practicing this type of breathing, are walking around chronically oxygen deprived.
In fact, both slow and rapid yogic breathing practices, if done appropriately, do not yield significant changes in oxygen or carbon dioxide levels. The main reason for this is that the effect of the deeper breath in long, slow, deep breathing is counterbalanced by the slower respiration rate. Deeper breathing with a typical respiration rate would actually lead to clinical hyperventilation, a potentially harmful state, which should be taken into account when practicing yogic breathing.
There is a growing body of evidence that yogic breathing improves gas exchange under altered, challenging conditions. In 1968, Shanker Rao from the Armed Forces Medical College in Pune, India looked at one subject who attempted yogic respiratory control at two different altitudes. The observations were carried out in the southwestern foothills of the Himalayas (12,500 ft.) and in Pune (1,800 ft.). He observed that the subject met increased demands for oxygen at high altitude by using long slow yogic breathing, which was effectively improving respiratory efficiency by increasing the amount of air exchanged in each breath instead of increasing the frequency of respiration.
Recent studies with a larger group of subjects support these early findings. In 2001, Luciano Bernardi et al. conducted a study in Albuquerque NM, comprising of 19 controls and 10 western yoga trainees to test breathing patterns and autonomic modulation at simulated high altitude. The researchers found that yoga trainees maintained better blood oxygenation without increasing ventilation (slow yogic breathing being a more efficient breathing method) and had reduced sympathetic activation when compared to controls.
A subsequent study looked at Caucasian yoga trainees, Nepalese Sherpas, and Himalayan Buddhist monks. They found that yoga trainees were able to maintain oxygen exchange rates at high altitude that resembles the Himalayan natives. Therefore, respiratory adaptations induced by yoga practice may represent an efficient strategy to cope with altitude-induced hypoxia (inadequate oxygen supply).
In summary, slow yogic breathing is the most efficient way to ventilate and exchange oxygen and carbon dioxide. However, in addition to this benefit, long slow yogic breathing is also known to also offer numerous additional benefits including beneficial effects on heart rate variability, the chemoreflex response, autonomic function, and even on mood and mental health.
Nikhil Rayburn grew up practicing yoga under mango trees in the tropics. He is a certified Kundalini Yoga teacher and has taught yoga to children and adults in Vermont, New Mexico, Connecticut, India, France, and Mauritius. He is a regular contributor to the Kundalini Research Institute newsletter and explores current yoga research.
Sat Bir Singh Khalsa, Ph.D. is the KRI Director of Research, Research Director for the Kripalu Center for Yoga & Health, and Assistant Professor of Medicine at Harvard Medical School. He has practiced a Kundalini Yoga lifestyle since 1973 and is a KRI certified Kundalini Yoga instructor. He has conducted research on yoga for insomnia, stress, anxiety disorders, and yoga in public schools. He is editor in chief of the International Journal of Yoga Therapy and The Principles and Practice of Yoga in Health Care and author of the Harvard Medical School ebook Your Brain on Yoga.