Ujjayi breathing is a breath technique employed in a variety of Taoist and Yoga practices. In relation to Yoga, it is sometimes called "the ocean breath". Unlike some other forms of pranayama, the ujjayi breath is typically done in association with asana practice.
Ujjayi is a diaphragmatic breath, which first fills the lower belly (activating the first and second chakras), rises to the lower rib cage (the third and fourth chakras), and finally moves into the upper chest and throat. The technique is very similar to the three-part Tu-Na breathing found in Taoist Qigong practice.
Inhalation and exhalation are both done through the nose. The "ocean sound" is created by moving the glottis as air passes in and out. As the throat passage is narrowed so, too, is the airway, the passage of air through which creates a "rushing" sound. The length and speed of the breath is controlled by the diaphragm, the strengthening of which is, in part, the purpose of ujjayi. The inhalations and exhalations are equal in duration, and are controlled in a manner that causes no distress to the practitioner.
"Ujjayi" comes from the Sanskrit prefix "ud" (उद्) added to it and root "ji" (जि): "ujji" (उज्जि), meaning "to be victorious". Ujjayi (उज्जायी), thus means "one who is victorious". Ujjayi breath means "victorious breath".
According to Tirumalai Krishnamacharya, who taught the creators of Ashtanga Vinyasa Yoga, Iyengar Yoga and others, Ujjayi Pranayama is a balancing and calming breath which increases oxygenation and builds internal body heat. The Hawaiian yoga teacher Wai Lana says Ujjayi Pranayama "tones the lungs and encourages the free and healthy flow of prana", while helping to regulate blood pressure and bringing oxygen to all parts of the lungs."
Ujjayi breathing may be used continuously throughout Ashtanga Vinyasa Yoga, and is frequently used in Power Yoga and Vinyasa, or Flow Yoga. This breath enables the practitioner to maintain a rhythm to his or her practice, take in enough oxygen, and helps build energy to maintain practice, while clearing toxins out of the bodily system. This breath is especially important during transition into and out of asanas (postures), as it helps practitioners to stay present, self-aware and grounded in the practice, which lends it a meditative quality.
Ujjayi, sometimes referred to as "cobra breathing", is also a helpful way for the yogi or yogini to keep the vital life force, prana, circulating throughout the body rather than escaping from it. Ujjayi is said to be similar to the breathing of a new-born baby before the prana begins to flow out into the world's attractions.
See also 
- A variant of ujjayi breathing, which involves inhaling and exhaling through particular nostrils, is Pratiloma ujjayi,