To practice ujjayi pranayama, the breath is inhaled deeply through the nostrils, with the glottis at the back of the throat slightly constricted so that it makes a gentle hissing sound. The constriction is maintained on the exhalation, which is also through the nose. It can be practiced with a retention of breath at the top of the inhalation, although this is optional.
The oceanic, whispering or hissing sound produced during ujjayi pranayama is known as ajapa mantra, or unspoken mantra. This is said to slow down the breath, focus awareness and smooth the flow of air. The sound can also be an anchor for the mind, preventing it from wandering.
Ujjayi pranayama can be practiced for several minutes initially, building up to 10 to 15 minutes. It is also practiced during asana practice, particularly throughout Ashtanga and Vinyasa Flow yoga practice, because it helps to warm the body and calm the mind.