During normal breathing, only 10% of total respiratory capacity is used. A person inhales 500 cubic centimeters (0.5 litre) of air during normal breathing whereas during deep inhalation, the amount of air intake increases about 6 times i.e. almost 3000 cubic centimetres (3 litres) while the total amount of air that can be inhaled could be around 4.5 to 5 litres. Hence, regular practice of pranayama increases lung capacity of the individuals and the purpose of pranayama is to enable the respiratory system to function at its best.

The respiratory system is the most important function in all living beings, because one can survive without food and water for few days but as respiration stops, so does life. Pranayama lengthens the time taken for each breath in and out, thereby slowing down the ageing process and hence increases one’s life span. The continuous practise of pranayama results in steady mind, will power and sound judgement. When an individual’s breath is irregular, the mind wavers whereas when the breath is steady, so also is the mind.

The right hemisphere of the brain corresponds to the parasympathetic nervous system and is responsible for intuitive, artistic and functions which are ida (left) nadi functions. The left hemisphere of the brain corresponding to the sympathetic nervous system is responsible for rational, logical and analytical thinking which are functions of pingala (right) nadi. By balancing the ida and pingala nadi (left and right breathing), the activity of human brain is balanced. When we breathe properly through left nostril, right side of the brain is activated and vice versa.

Pranayama brings about a positive change in the mental state of practitioners because during pranayama, breathing is from the base of the diaphragm which results in relaxation of thoracic diaphragm and other respiratory muscles of the neck. As a result facial muscles are relaxed which in turn loosens the sense organs such as eyes, ears, nose, tongue and skin. As the sense organs are relaxed, tension or stress in the brain is reduced which helps the practitioner to attain concentration, mental stability and calmness.