Yin yoga is a slow-paced style of yoga with postures, or asanas, that are held for longer periods of time—for beginners, it may range from 45 seconds to two minutes; more advanced practitioners may stay in one asana for five minutes or more.
Yin yoga poses apply moderate stress to the connective tissues of the body—the tendons, fascia, and ligaments—with the aim of increasing circulation in the joints and improving flexibility. A more meditative approach to yoga, yin aims at cultivating awareness of inner silence, and bringing to light a universal, interconnecting quality.
The practice of holding yoga postures or asanas for extended periods of time has always been a significant part of traditional yoga practice, both in the hatha yoga tradition of India and in the Taoist yoga tradition of the greater China area. Contemporary schools of hatha yoga have also advocated holding some poses for relatively long periods of time. For example, BKS Iyengar recommended holding the Supta Virasana asana (reclining hero pose) for 10–15 minutes. For that matter, long-held stretches have been and are commonly recommended in other physical disciplines, such as gymnastics and dance, to increase flexibility. For example, ballerinas are commonly counselled to open their hips by approximating the splits position for long periods of time.
Taoist yoga practices from China also included yin-style poses in the Taoist system of “Internal Alchemy”—practiced for the purpose of improving health and longevity. Techniques for stretching of this type have been practiced for centuries in China and Taiwan as part of Taoist yoga, which was sometimes known as Dao Yin. Taoist priests taught long-held poses, along with breathing techniques, to Kung Fu practitioners beginning 2000 years ago, to help them fully develop their martial arts skills.