Yin yoga is a slow-paced style of yoga as exercise, incorporating principles of traditional Chinese medicine with postures that are held for longer periods of time than in other yoga styles. For beginners, postures may be held for 45 seconds to two mins. More advanced practitioners may stay in one posture for 5 minutes or more. The sequences of postures are meant to stimulate the channels of the body. They’re known as meridians In Chinese medicine, and as nadis in hatha yoga.