Ashtanga yoga is a classification of classical Yoga according to Patanjali’s Yoga Sutras. It is a comprehensive system that integrates eight spiritual practices of Yoga, including physical postures, breath control and sense withdrawal. It also includes concentration, meditation, and ethical principles. Practitioners of Ashtanga often find it to be the most challenging style of Yoga due to the need for exceptional patience and unwavering discipline to master the series and advance in the practice.