The essence of Yin yoga is surrender. It focuses on postures that lengthen the muscles surrounding the hips, pelvis, and lower back. Students typically hold these postures for 3-10 minutes per side in order to lengthen the connective tissue that surrounds the joints and increase its elasticity. Since a Yin yoga practice often includes several long, seated forward bending postures, it also restores energy and calms the nervous system.