Definition - What does Puraka mean?
Puraka is a Sanskrit word that means "inhalation." Together with kumbhaka (breath retention) and recaka (exhalation), puraka is a part of yogic breathing -- a process of drawing in air that is supposed to be smooth and continuous.
B.K.S. Iyengar, the founder of Iyengar yoga, says that prana (life force energy) is invited to come in during puraka. He believes that in order to make room for prana, one must move the individual self out of the way. The energy generated through puraka expands the practitioner's consciousness and creates awareness, allowing more space for prana to flow freely.
Yogapedia explains Puraka
Performing puraka stimulates the body, enlarges the chest cavity, fills the lungs with air and moves the diaphragm down. It is believed that beginners should first practice puraka and recaka with a 1:2 duration ratio before moving on to practice kumbhaka.
At the end of a proper puraka, the lungs should be filled and expanded completely, but it should still be a slow and controlled act; the time taken to perform puraka should remain consistent throughout repetitions. If a practitioner has to pause one or more times during the process of a single puraka, the process might be called a broken puraka.
Puraka and the process of yogic breathing is a core skill for any yoga practitioner. Mastering the puraka-kumbhaka-recaka cycle not only aids in meditation and pranayama exercises, it also helps the practitioner surrender to asanas during their physical practice and can serve as a means of measuring the duration of poses.