All yoga styles fall under the same blanket term of yoga, but in terms of their energy, they can be divided into two categories: Yang forms of yoga are active, whereas yin forms are more passive.
Styles like ashtanga, vinyasa, and power yoga are obviously yang, as they quickly flow from movement to movement.
On the opposite end of the spectrum is yin yoga. In a yin practice, poses are usually held for at least a minute and up to 20 minutes. Poses are held for longer periods of time to work on the deeper components of the physical body: connective tissue, ligaments, tendons, fascia, and even the bones. Yin asanas (poses) mainly target the area between the navel and the knees. The long holds also foster an inner stillness that lends itself to a meditative asana practice. On the other hand, yang practices primarily work on improving the strength and flexibility of the superficial muscles.
Yin yoga is centered on around 30 poses. Some share the Sanskrit names of traditional yoga poses, such as Balasana (Child’s pose) and Savasana (Corpse pose), and some have their own English names like Shoelace pose.
Specific sequences are used to target the meridians, or the subtle energy channels described in Chinese medicine, which are similar to the nadis in traditional yoga. Yin yoga poses encourage students to find their edge—to bring the body to the appropriate depth without going too far. Once there, students are invited to remain still, giving the pose the time it needs to work on the body’s deeper tissues.
Yin yoga has its roots in China’s Taoist yoga. It arrived in the West in the 1970’s primarily via Paulie Zink, who was taken under the wings of a Kung-fu master to become his protégé. Zink’s martial arts studies included Taoist yoga, and he evolved this yoga practice by adding his own postures and sequences.
Yin yoga’s establishment in the U.S. today is also credited to Paul Grilley, one of Zink’s students, and Sarah Powers, one of Grilley’s students, who coined the term “yin yoga.”
The Yin Yoga Institute, established by Paulie Zink, offers 200-hour yin yoga certification courses. According to the institute, these are the only official yin yoga teacher-training courses (YTTC).
Paul Grilley offers yin-based YTTCs around the country, and many yoga schools also offer yin yoga intensives. These courses are meant to compliment and deepen the 200-hour YTT courses.