From pranayama (q.v.) arises laghava (lightness).
All beings say the ajapa-Gayatri, which is the expulsion of the breath by Hamkara, and its inspiration by Sahkara, 21,600 times a day. Ordinarily, the breath goes forth a distance of 12 fingers’ breadth, but in singing, eating, walking, sleeping, coition, the distances are 16, 20, 24, 30, and 36 breadths respectively.
In violent exercise these distances are exceeded, the greatest distance being 96 breadths. Where the breathing is under the normal distance, life is prolonged. Where it is above that, it is shortened. Puraka is inspiration, and recaka expiration. Kumbhaka is the retention of the breath between these two movements. Kumbhaka is, according to the Gheranda Samhita, of eight kinds: sahita, suryabheda, ujjayi, sitali, bhastrika, bhramari, murchchha, and kevali.
Pranayama similarly varies. Pranayama is the control of the breath and other vital airs. It awakens sakti, frees from disease, produces detachment from the world, and bliss. It is of varying values, being the best (uttama) where the measure is 20; middling (madhyama) when at 16 it produces spinal tremor ; and inferior (adhama) when at 12 it induces perspiration. It is necessary that the nadi should be cleansed, for air does not enter those which are impure. The cleansing of the nadi (nadi-suddhi) is either samanu or nirmanu–that is, with or without, the use of bija. According to the first form, the yogi in padmasana does guru-nyasa according to the directions of the guru. Meditating on “yam,” he does japa through Ida of the bija 16 times, kumbhaka with japa of bija 64 times, and then exhalation through the solar nadi and japa of bija 32 times.
Fire is raised from manipura and united with prthivi. Then follows inhalation by the solar nadi with the vahni bija, 16 times, kumbhaka with 64 japa, followed by exhalation through the lunar nadi and japa of the bija 32 times. He then meditates on the lunar brilliance gazing at the tip of the nose, and inhales Ida with japa of the bija “tharm” 16 times. Kumbhaka is done with the bija vam 64 times. He then thinks of himself as flooded by nectar, and considers that the nadis have been washed. He exhales by Pingala with 32 japa of the bija lam, and considers himself thereby as strengthened. He then takes his seat on a mat of kusa-grass, a deerskin, etc., and, facing east or north, does pranayama.
For its exercise there must be, in addition to nadi suddhi, consideration of proper place, time and food. Thus, the place should not be so distant as to induce anxiety, nor in an unprotected place, such as a forest, nor in a city or crowded locality, which induces distraction. The food should be pure, and of a vegetarian character. It should not be too hot or too cold, pungent, sour, salt, or bitter. Fasting, the taking of one meal a day, and the like, are prohibited. On the contrary, the Yogi should not remain without food for more than one jama (three hours). The food taken should be light and strengthening.
Long walks and other violent exercises should be avoided, as also-certainly in the case of beginners-sexual intercourse. The stomach should only be half filled. Yoga should be commenced, it is said, in spring or autumn.
As stated, the forms of pranayama vary. Thus, sahita, which is either with (sagarbha) or without (nirgarbha) bija, is according to the former form, as follows: The sadhaka meditates on Vidhi (Brahma), who is full of rajo-guna, red in colour, and the image of akara. He inhales by Ida in six measures (matra). Before kumbhaka he does the uddryanabhandha mudra, Meditating on Hari (Visnu) as sattvamaya and the black bija ukara, he does kumbhaka with 64-japa of the bija ; then, meditating on S’iva as tamomaya and his white bija makara, he exhales through Pingala with 32 japa of the bija; then, inhaling by Pingala, he does kumbhaka, and exhales by Ida with the same bija. The process is repeated in the normal and reversed order.