The Yin practice concentrates on keeping joints mobile while increasing flexibility. The practice is quiet and passive, suitable for all levels! In Yin practices yoga students are still and passive and therefore able to actually stretch the joints and the connective tissues surrounding them in addition to the muscle. Yin practices help joints to stay moist and supple as we age rather than drying out and leading to stiffness and immobililty. The safe way to exercise (stress) these tissues is to apply a tolerable pressure for a long period of time (ie: traction) therefore each stretching posture is held for up to 5 minutes. In a yin practice, time is the critical factor resulting in long, slow and deep postures.