Physiology Of Pranayama
Breathing is a spontaneous process which occurs automatically without our awareness. It is written in the ”Hatha Yoga Pradipika”, the ancient text on yoga: “Life is the period between one breath and the next. A person who breathes correctly acquires control of the whole being.” The ancient yogis were fully aware of the importance of breath. They knew the value of Pranayama and ways of correct breathing and hence lived a healthy and long life.
The process of respiration has three components. The first is the inspiration of air and is called Pooraka. Next is Kumbhaka and it means retention of the breath, and the third one is Rechaka which is the expiration of air. Poorak and Rechaka are the natural processes but the Kumbhaka is not natural and hence It can be said that Kumbhaka is pranayama, not the Pooraka or Rechaka.
Kumbhaka is of three types
Bahir Kumbhaka is the retention of breath at the end of expiration.
Antar Kumbhaka is the retention of the breath after the inspiration of air.
Kevala Kumbhaka implies holding the breath with no particular state of respiration in consideration. It is one of the final stages of yoga parallel with the state of samadhi.
Benefits of Slow Inhalation, Expiration & Kumbhaka
Benefits of Slow Inhalation
The heart rate is slowed in slow inspiration (inhalation). With a slower rate, the resting period of the heart is prolonged. The heart muscles receive more rest. The cavities of the heart are better filled with blood. During the next pumping action of contraction, the heard is able to push more blood into the circulatory system with a better force. Thus general circulation is improved.
Benefits of Kumbhaka Pranayama
During Kumbhaka, which is the retention of the breath, no new air enters the lungs, so no more oxygenation takes place. This causes oxygen tension in the blood to get reduced. The brain is most sensitive to this lowered oxygen tension, as its needs for oxygen are the greatest. If the quality of the blood is below par, the brain tries to get more blood in quantity. Most of the capillaries in the brain and even elsewhere in the body are either lying dormant in a collapsed state or are closed. In order to receive a greater quantity of blood, these capillaries are opened up and the circulation improves. The action is more profound in the brain.
Benefits Of Slow Exhalation
If the release of breath (expiration or exhalation) is sudden, the elastic tissue in the lungs will snap back violently, but if the release of breath is slow and controlled, it will maintain its elasticity. Next advantage of slow Rechaka is in the brain and psyche. Slow expiration needs a conscious effort which further needs the help of the cerebral cortex of the brain. The cerebral cortex sends inhibitory impulses to the respiratory center in the midbrain. These inhibitory impulses from the cortex overflow into the adjoining area of the hypothalamus concerned with emotions, and quieten this area.
Once a practitioner becomes a silent witness to his own breath and makes a conscious effort to breathe out slowly, his thought processes and the senses are switched off. This is the state of Pratyahara which is actually withdrawal of the senses from the external world. Thus slow exhalation leads the practitioner to the state of Pratyahara, the fifth stage of Ashtanga Yoga.
Throughout our life, breathing process continues involuntarily. But during slow expiration and inspiration, the activity of controlling the breath shift from the respiratory center to the cerebral cortex. This involvement of the cerebral cortex causes the cortex to develop. Further development of the cerebral cortex leads to a higher stage of the evolutionary cycle.