1. Inhalation or inspiration, which is termed puraka (filling up)
2. Exhalation or expiration, which is called rechaka (emptying the lungs)
3. Retention or holding the breath, a state where there is no inhalation or exhalation, which is termed kumbhaka.
In Hatha Yoga texts kumbhaka is also used in a loose generic sense to include all the three respiratory processes of inhalation, exhalation and retention.
A kumbha is a pitcher, water pot, jar or chalice. A water pot may be emptied of all air and filled completely with water, or it may be emptied of all water and filled completely with air. Similarly, there are two states of kumbhaka namely
1. When breathing is suspended after full inhalation (the lungs being completely filled with life giving air)
2. When breathing is suspended after full exhalation (the lungs being emptied of all noxious air.)
The first of these states, where breath is held after a full inhalation, but before exhaiation begins, is known as antara kumbhaka. The second, where breath is held after a full exhalation, but before inhalation begins is known as bahya kumbhaka. Antara means inner or interior, while bahya means outer or exterior. Thus, kumbhaka is the interval or intermediate time between full inhalation and exhalation (antara kumbhaka) or between full exhalation and inhalation (bahya kumbhaka). In both these types breathing is suspended and restrained.
Pranayama is thus the science of breath. It is the hub round which the wheel of life revolves. 'As lions, elephants and tigers are tamed very slowly and cautiously, so should prana be brought under control very slowly in gradation measured according to one's capacity and physical limitations. Otherwise it will kill the practitioner,' warns the Hatha Yoga Pradipika (Chapter II, verse 16).
The yogi's life is not measured by the number of his days but by the number of his breaths. Therefore, he follows the proper rhythmic patterns of slow deep breathing. These rhythmic patterns strengthen the respiratory system, soothe the nervous system and reduce craving. As desires and cravings diminish, the mind is set free and becomes a fit vehicle for concentration. By improper practice of pranayama the pupil introduces several disorders into his system like hiccough, wind, asthma, cough, catarrh, pains in the head, eyes and ears and nervous irritation. It takes a long time to learn slow, deep, steady and proper inhalations and exhalations. Master this before attempting kumbhaka.
As a fire blazes brightly when the covering of ash over it is scattered by the wind, the divine fire within the body shines in all its majesty when the ashes of desire are scattered by the practice of pranayama. 'The emptying the mind of the whole of its illusion is the true rechaka (exhalation). The realisation that "I am Atma (spirit)" is the true puraka (inhalation). And the steady sustenance of the mind on this conviction is the true kumbhaka (retention). This is true pranayama,' says Sankaracharya.
Every living creature unconsciously breathes the prayer 'So' ham' (Sah = He; Aham = I - He, the Immortal Spirit, am I) with each inward breath. So also with each outgoing breath each creature prays 'Hamsah' (I am He). This ajapa-mantra (unconscious repetitive prayer) goes on for ever within each living creature throughout life. The yogi fully realises the significance of this ajapa-mantra and so is released from all the fetters that bind his soul. He offers up the very breath of his being to the Lord as a sacrifice and receives the breath of life from the Lord as his blessing.
Prana in the body of the individual (jivatma) is part of the cosmic breath of the Universal Spirit (Paramatma). An attempt is made to harmonise the individual breath (pinda-prana) with the cosmic breath (Brahmanda-prana) through the practice of pranayama.
It has been said by Kariba Ekken, a seventeenth century mystic;
If you would foster a calm spirit, first regulate your breathing; for when that is under control, the heart will be at peace; but when breathing is spasmodic, then it will be troubled. Therefore, before attempting anything, first regulate your breathing on which your temper will be softened, your spirit calmed.
'The chitta (mind, reason and ego) is like a chariot yoked to a team of powerful horses. One of them is prana (breath), the other is vasana (desire). The chariot moves in the direction of the more powerful animal, If breath prevails, the desires are controlled, the senses are held in check and the mind is stilled, If desire prevails, breath is in disarray and the mind is agitated and troubled. Therefore, the yogi masters the science of breath and by the regulation and control of breath, he controls the mind and stills its constant movement. In the practice of pranayama the eyes are kept shut to prevent the mind from wandering. 'When the prana and the manas (mind) have been absorbed, an indefinable joy ensues.' (Hatha Yoga Pradipika, Chapter IV, verse 30).
Emotional excitement affects the rate of breathing; equally, deliberate regulation of breathing checks emotional excitement. As the very object of Yoga is to control and still the mind, the yogi first learns pranayama to master the breath. This will enable him to control the senses and so reach the stage of pratyahara. Only then will the mind be ready for concentration (dhyana).
The mind is said to be two fold - pure and impure. It is pure when it is completely free from desires and impure when it is in union with desires. By making the mind motionless and freeing it from sloth and distractions, one reaches the state of mindlessness (amanaska.), which is the supreme state of samadhi. This state of mindlessness is not lunacy or idiocy but the conscious state of the mind when it is free from thoughts and desires. There is a vital difference between an idiot or a lunatic on the one hand, and a yogi striving to achieve a state of mindlessness on the other. The former is careless; the latter attempts to be carefree. It is the oneness of the breath and mind and so also of the senses and the abandonment of all conditions of existence and thought that is designated Yoga.
One of the most subtle forms of energy is air. This vital energy which also pervades the human body is classified in five main categories in the Hatha Yoga texts according to the various functions performed by the energy. These are termed vayu (wind) and the five main divisions are
1. prana (here the generic term is used to designate the particular), which moves in the region of the heart and controls respiration
2. Apana, which moves in the sphere of the lower abdomen and controls the function of eliminating urine and faeces
3. Samana, which stokes the gastric fires to aid digestion
4. Udana, which dwells in the thoracic cavity and controls the intake of air and food
5. Vyana., which pervades the entire body and distributes the energy derived from food and breath.
There are also five subsidiary' vayus.
1. Naga, which relieves abdominal pressure by belching
2. Kurma, which controls the movements of the eyelids to prevent foreign matter or too bright a light entering the eyes
3. Krkara, which prevents substances passing up the nasal passages and down the throat by making one sneeze or cough
4. Devadatta, which provides for the intake of extra oxygen in a tired body by causing a yawn and lastly
5. Dhanamjaya, which remains in the body even after death and sometimes bloats up a corpse.