Yoga nidra is among the deepest possible states of relaxation while still maintaining full consciousness.
Yoga nidra or yogic sleep is a state of consciousness between waking and sleeping, like the "going-to-sleep" stage. It is a state in which the body is completely relaxed, and the practitioner becomes systematically and increasingly aware of the inner world by following a set of verbal instructions.
Yoga nidra consists of breathing exercises (pranayama) and guided meditation to put you in the deepest possible state of relaxation while still maintaining full consciousness. Benefits include the release of muscular, emotional and mental tension and has been found to reduce tension and anxiety