Rebecca Barnes instructs the following:
Yin yoga promotes stillness in the body and mind. While most forms of yoga focus on the muscles, yin yoga is meant for the joints, the connective tissue called facia, and has many benefits for the body. It is a great compliment to more rigorous forms of exercise as it opens the body and stimulates our connective tissue.
Yin class is composed of all seated or reclined poses that are held anywhere from 2-7 minutes each. Yin yoga will challenge the mind to remain present while physically and mentally releasing tension. Expect to leave this class relaxed and renewed with a sense of calm energy.