Pranayama

The practice involves two primary techniques: exhalation, known as pracchardana, which entails expelling air from the stomach through the nostrils, and retention, known as vidharana, which focuses on the controlled restraint of breath.

[13] According to Theos Bernard, the ultimate aim of pranayama is the suspension of breathing (kevala kumbhaka), "causing the mind to swoon".

[19] Paramahansa Yogananda writes, "The real meaning of Pranayama, according to Patanjali, the founder of Yoga philosophy, is the gradual cessation of breathing, the discontinuance of inhalation and exhalation".

[20] The yoga scholar Andrea Jain states that pranayama was "marginal to the most widely cited sources" before the 20th century, and that the breathing practices were "dramatically" unlike the modern ones.

[21][22] According to the Pali Buddhist Canon, the Buddha, prior to his enlightenment, practiced a meditative technique involving pressing the palate with the tongue and forcibly attempting to restraining the breath.

[23] In some Buddhist teachings or metaphors, breathing is said to stop with the fourth jhana, though this is a side effect of the technique and does not result from purposeful effort.

[27][28] In the Nyingma tradition of Dzogchen these practices are collected in the textual cycle known as "The Oral Transmission of Vairotsana" (Vai ro snyan brgyud).

[30] In a systematic review of yoga breathing exercises and blood pressure, a moderate but statistically significant beneficial effect was found.