Ashtanga vinyasa yoga one of the three key principles in Ashtanga Vinyasa Yoga, alongside breath and drishti. There are three principal bandhas which are considered internal body locks: Both Pattabhi Jois and Sharath Jois recommend practicing Mula and Uddiyana bandha even when not practicing asana. Pattabhi Jois has this to say: (translated quote) "You completely exhale, apply mulabandha and after inhaling you apply uddiyana bandha. Both bandhas are very important... After bandha practice, take (your attention) to the location where they are applied and maintain that attention at all times, while walking, talking, sleeping and when walk is finished. Always you control mulabandha".
Ashtanga vinyasa yoga asana practice, but also stated that the breathing should be deep breathing with sound. He reiterated this notion in a conference in 2013 stating, "You do normal breath, inhalation and exhalation with sound. Ujjayi breath is a type of prāṇāyāma. This is just normal breath with free flow". In 2014 published on YouTube, Manju Jois dodged the question, "What is the difference between Ujjayi breathing and free breathing?" by saying that "the breathing in Ashtanga should be long and deep with the sound like the ocean". He also states that if you don't make sound, that is okay, too. However