Tasmin sati svasaprasvasayor-gativicchedah pranayamah – “Regulation of breath or the control of Prana is the stoppage of inhalation and exhalation, which follows after securing that steadiness of posture or seat.” This is the definition of Pranayama in the Yoga-sutras of Patanjali.
‘Svasa’ means inspiratory breath. ‘Prasvasa’ means expiratory breath. You can take up the practice of Pranayama after you have gained steadiness in your Asana (seat). If you can sit for 3 hour in one Asana, continuously at one stretch, you have gained mastery over the Asana. If you are able to sit from half to one hour even, you can take up the practice of Pranayama. You can hardly make any spiritual progress without the practice of Pranayama.
Prana is Vyashti, when the individual is concerned. The sum total of the cosmic energy or cosmic Prana is Hiranyagarbha who is known as the floating ‘Golden-Egg’. Hiranyagarbha is Samashti Prana. One match stick is Vyashti (single). The whole match box is Samashti. A single mango-tree is Vyashti. The whole mango grove is Samashti. The energy in the body is Prana. By controlling the motion of the lungs or respiratory organs, we can control the Prana that is vibrating inside. By control of Prana, the mind can be easily controlled, because the mind is fastened to the Prana, like the bird to the string. Just as the bird that is tied to a post by a string, after flying here and there, finds its resting place in the post, so also this mind-bird after running hither and thither, in various sensual objects, finds its resting place during deep sleep in the Prana.
Pranayama (According to the Gita)
Apane juhvati pranam pranepanam tathapare; Pranapanagatee ruddhva pranayamaparayanah (Gita, Ch. IV-29.). Others offer Prana (outgoing breath) in Apana (incoming breath) and Apana in Prana, restraining the passage of Prana and Apana, absorbed in Pranayama.
Pranayama is a precious Yajna (sacrifice). Some practise the kind of Pranayama called Puraka (filling in). Some practise the kind of Pranayama called Rechaka (emptying). Some are engaged in the practice of Pranayama called Kumbhaka, by impeding the outward passage of air, through the nostrils and the mouth, and by impeding the inward passage of the air, in the opposite direction.
Pranayama (According To Sri Sankaracharya)
“Pranayama is the control of all life-forces by realising naught but Brahman in all things as the mind, etc. “The negation of the Universe is the outgoing breath. The thought: ‘I am Brahman’ itself is called the incoming breath. The permanence of that thought thereafter is the restrained breath. This is the Pranayama of the wise, while the pressing of the nose is only for the unknowing.” (Aparokshanubhuti, 118-120).
‘The Science of Pranayama’ by Sri Swami Sivananda