Yoga nidra or yogic sleep is a procedure derived from the nyasaya practice of the Tantras.
Nyasa is a method of consecration of the human body involving specific mantras.
According to the tradition, it is a procedure for instilling divine consciousness in various parts of the body.
Swami Satyananda Saraswathi of Bihar School of Yoga developed the method of yoga nidra. It is widely used as a method of relaxation and as well as a form of meditation. It has also been attributed with healing powers and used for this purpose for many yoga teachers.
Yoga nidra involves relaxing the body and rotating awareness among various parts of the body in a rapid succession. As energy follows awareness, yoga nidra can also serve as an energizing technique.
While practicing yoga nidra, one is believed to operate at the threshold of consciousness/unconsciousness. To bring about change in oneself, an idea called a resolution, is made by practitioner during yogic sleep.
From a modern perspective, yoga nidra is a method of passive relaxation coupled with focusing of awareness and positive affirmation.
It has the components of Jacobson’s Progressive Muscular Relaxation and Schultz’s Autogenic Relaxation.
There are very elaborate, and very simple practices in yoga nidra. They are used for spiritual purposes and for health and wellness.
In a session of yoga nidra, the teachers instruct practitioners carry out the process in a relaxed state, usually lying on the back in savasana.
The duration of the session varies based on the elaborateness of the procedure adopted by the teacher. A short variation takes about fifteen minutes.