Ashtanga vinyasa yoga system (pranayama), posture (asana), and looking place (drishti). These are considered core concepts for ashtanga yoga practice; cover the three levels of purification: the body, nervous system and the mind; and are supposed to be "performed in conjunction with each other". The asanas in ashtanga yoga follow a set sequence as described above. Their stated purpose is for strength and flexibility of the body. Officially, the style has very little alignment instruction. However, many of Patthabi Jois' earliest teachers did emphasize very detailed alignment and posture-break down instructions, based on information they gathered outside of Pattabhi Jois direct instruction. Sharath's
Ashtanga vinyasa yoga the teacher is to guide as well as provide adjustments or assists in postures. In other locations, twice per week Mysore-style classes are now substituted with led classes, where the teacher takes a group through the same series at the same time. The inclusion of two led classes per week was only included in P. Jois' senior years. Usually an Ashtanga practice begins with five repetitions of Surya Namaskara A and five repetitions of Surya Namaskara B, followed by a standing sequence. Following this the practitioner begins one of six series, followed by what is called the closing sequence. The