Pranayama – Yoga divides respiration into three phases. Puraka or inhalation, Rechaka or exhalation and Kumbhaka breath retention.  Puraka and Rechaka are natural phases, which makes Kumbhaka Pranayama.

Kumbhaka is then divided into three further phases. Bahir is retention at the end of a breath. Antar is retaining the breath on an inhalation. Kevala Kumbhaka means holding the breath with no particular emphasis.  


Breath retention should only be practiced under the guidance of an experienced teacher, and this article is not intended as a teaching guide. Yoga tells us holding the breath does have benefits if performed with awareness and progressively.

During breath retention no new Oxygen is taken into the body, and Carbon Dioxide is retained. It is the build up of Carbon Dioxide that in the end forces the next breath. Carbon Dioxide is essential for good health, and withholding Co2 does have benefits, up to a point. Holding the breath creates a response called cerebral anoxia. The capillaries, where gas exchange takes place do not all work at the same time, so when the brain calls for more oxygen, the resting capillaries respond through cerebral vasodilation.


Cerebral vasodilation is the widening of the blood vessels, due to smooth muscle relaxing. The main function of vasodilation is to increase blood flow to a particular part of the body most in need.  Cerebral vasodilation also reduces blood pressure.

Cerebral vasodilation

Fast rapid and shallow breathing will express too much Co2, which results in hyperventilation. Left untreated there is evidence this will cause long lasting damage. The brain requires Co2 for healthy functioning, and a lack of Co2  affects the nervous system putting the body on alert . The Sympathetic nervous system is triggered, the heart and respiratory rate increase preparing the body for action.


During the inhalation the heart rate increases, and on the exhalation the heart rate decreases. This is called Respiratory sinus arrhythmia (RSA) During the inhalation blood is diverted to the lungs, and this causes less blood to be available to the rest of the body. The heart reacts by increasing heart rate, in an effort to compensate. During the exhalation phase more blood is made available to the body, and the heart slows down. There is evidence that the inhalation phase is connected to the Sympathetic nervous system, and the exhalation is connected to the Parasympathetic nervous system.   

As the Parasympathetic nervous system triggers the rest and relax response, the evidence suggests slowing down the exhalation has benefits.     


There would appear to be considerable scientific evidence supporting the claim by Yogis of the benefits of Pranayama. It is important to remember when embarking on a practice, to seek the advice of a well trained teacher with a solid personal background in Pranayama.

Martin Thompson   


Call Martin on: 07787357306