Definition - What does Rechaka mean?
Rechaka, or rechaka pranayama, is a Sanskrit word that means "exhalation." It refers to a form of yogic breathing in which the exhalation is lengthened, while the inhalation remains free. Together with puraka (inhalation) and abhyantara kumbhaka (breath retention), rechaka is one of the three stages utilized in pranayama.
Some yogic sources state that pranayama is retention, and that puraka and rechaka are only methods of affecting it. Others state that recaka is the most important part of pranayama, and that if the quality of the exhalation is not good, the quality of the whole pranayama practice is affected.
Yogapedia explains Rechaka
Exhalation is the third phase of respiration and it is normally a passive act. However, the yogic act of recaka should be a slow, controlled process. Some say it should be twice as long as the puraka.
A controlled and focused rechaka helps prepare the individual for the yogic limb that follows pranayama: pratyahara (withdrawal of the senses). If the practitioner observes and focuses on their breathing, it helps switch off other senses and mental processes.
Slow rechaka also helps to maintain the elasticity of the lungs. It offers some major benefits for the brain, as well. The slow respiration requires the help of the cerebral cortex, which sends impulses to the respiratory center. These impulses overflow into the hypothalamus (a center of emotion) and quiets that area, providing a soothing effect.