The term viṅyāsa refers to the alignment of movement and breath, a method which turns static yoga postures into a dynamic flow. The length of one inhale or one exhale dictates the length of time spent transitioning between postures. Poses are then held for a predefined number of breaths. In effect, attention is placed on the breath and the journey between the postures rather than solely on achieving perfect body alignment in a pose, as is emphasized in Hatha yoga.
The term vinyasa also refers to a specific series of movements that are frequently done between each pose in a series. This viṅyāsa 'flow' is a variant of Sūrya namaskāra, the Sun Salutation, and is used in other styles of yoga beside Ashtanga Vinyasa Yoga. A standard vinyāsa consists (for example) of the flow from caturaṅga, or plank, to caturaṅga daṇḍāsana, or low plank, to ūrdhva mukha śvānāsana or upward-facing dog, to Adho Mukha Svanasana, or downward-facing dog.
The breathing style used in Ashtanga Vinyasa Yoga is Ujjayi which is a relaxed diaphragmatic style of breathing, characterized by an ocean sound which resonates in the practitioner's throat. Throughout a practice, this specific breathing style is maintained in alignment with movements. The steady cycle of inhales and exhales provides the practitioner with a calming, mental focal point. Additionally, viṅyāsa and Ujjayi together create internal heat, which leads to purification of the body through increased circulation and sweating.
Another major principle of Ashtanga Vinyasa Yoga is the bandha, or muscle locking/contraction, which focuses energy in the body and is closely tied to the breath. There are a variety of bandhas (see below).
Ashtanga Vinyasa Yoga is different from many yoga classes in the west in that the order of poses is completely predefined. A practice will comprise of four main parts: an "opening sequence," one of the six main "series", a back-bending sequence, and a set of inverted postures, referred to as the "finishing sequence." Practice always ends with savasana, or resting pose. The opening sequence begins with 10 Sun Salutations and then several standing postures. Next, the practitioner will do one of the six main series, referred to as the Primary series (Yoga Chikitsa), Intermediate series (Nadi Shodhana)or Advanced A, B, C, or D (Sthira Bhaga) series level. Newcomers to Ashtanga Yoga practice the primary series, after learning the standing sequence. The Primary Series is the most important series as it forms the basis of the entire system. Practitioners may advance to more difficult series over a period of years or decades, but the goal of this style is not to learn the more difficult poses but rather to learn to maintain internal focus throughout the practice.
Daily or regular practice is highly emphasized in Ashtanga Vinyasa Yoga. Ashtanga Yoga is traditionally taught in Mysore style (supervised self practice, named after the city in India where Ashtanga originates), where each student moves through the practice at his or her own pace and level. An individual with an established Ashtanga practice might take between an hour and two hours, depending on his or her own personal speed, but a beginner will likely have a shorter practice. Yoga studios which teach Mysore practice are hard to find and these classes are often only taught by those authorized to teach by the Ashtanga Yoga Research Institute. It is more common to find classes devoted to a specific series, often at a standardized pace, and guided by an instructor. However, even traditional Mysore-style teachers offer "led" classes either weekly or monthly.