Yoga nidra can be practiced in a yoga class or at home. If you are doing it at home choose a quiet, closed room and make a habit of using it every day. The room should be well ventilated (but not breezy) and mosquito proof, with soft lighting and a comfortable temperature. If it is necessary to use a ventilating fan, keep away from its direct draught. In a yoga class each person should be physical separated from his or her neighbours. If yoga nidra is being done in the open, complete head and body cover is recommended and privacy is essential; sudden interruptions are to be avoided.
The best time to do yoga nidra is in the early morning and in the evening just before going to bed. The quiet hours from four to six in the morning are the most conducive to relaxation. Once you have chosen a time try to stick to it. Do not practice immediately after meals; allow at least two hours for digestion of a heavy meal and half an hour for settling of light refreshments.
Yoga nidra is practiced in the yogic pose called shavasana, corpse pose, also called mitrasana, dead man's pose (see Asana Pranayama Mudra Bandha, published by the Bihar School of Yoga). It has been scientifically determined that amongst all possible positions shavasana is the one most conducive to relaxation.
In this pose the practitioner lies flat on the back in the supine position on the floor, on a blanket or thin mat if necessary. The spine is straight. The arms are rested in line with and on each side of the body, but sufficiently apart so that the upper arms are not touching the side of the chest. The hands should be in a relaxed position, palms upwards and fingers curved inwards but not clenched. The legs are also straight but sufficiently spread to avow contact between the upper thighs. The feet are allowed to flop a little outwards. Eyes are closed.
The most desirable position calls for the head to be lying on the same surface as the rest of the body, but as many people find this uncomfortable, a thin pillow or folded blanket can be used for support; the corners of this pillow are also pulled under shoulders to ensure relaxation of the neck and shoulder muscles.
Avoid using thick pillows as they tend to cause more tension by arching the neck excessively.
Another source of discomfort may be the lower back (lumbar region), where it arches away from the floor. People who develop pain in this area during yoga nidra are advised to support it with a small pillow.
The position of the hands can also be varied. In the alternative position the hands are laid flat, one on top of the other, on the upper chest, with the elbows on the floor. The disadvantage of this position is that it increases physical contact, but it is suitable for people who find the preferred position too uncomfortable, for example because of an injury.
The principal aim of shavasana is to reduce sensory stimulation as much as possible and this is the reason for the arrangement of arms and legs indicated. It is therefore desirable to wear only a minimum of clothing, very loose, and to avoid covering the body. However, because the body temperature tends to drop during relaxation, a thin blanket can be used.
One of the biggest obstacles to the practice of yoga nidra is pain, stiffness and general tension in the body. This will not be a problem when it is used to conclude a yoga class. At home a number of alternatives are possible depending on the time available. For example, a preliminary practice of twenty minutes of asanas would be ideal. A typical sequence could commence with pawanmuktasana (limbering exercises) and from shavasana (corpse) run quickly through sarvangasana (shoulder stand), halasana (plough), matsyasana (fish), paschimottanasana (forward bend), bhujangasana (cobra), shalabhasana (locust), ardha matsyendrasana (spinal twist) to bhumi pada mastakasana (half headstand) or sirshasana (head-stand), or a selection of these, finishing up again in shavasana. These poses are described in Asana Pranayama Mudra Bandha but first you should get advice from a yoga teacher.
If you can spare only ten minutes, surya namaskara (salute to the sun) is an excellent practice for loosening up ail the joints and muscles in the body and massaging the internal organs. It is especially good in the morning after taking a bath and five to ten rounds are suggested. Finally, if you have no time even for this, then you can do naukasana (boat pose) which consists of raising the head and feet from shavasana, clenching the fists and tightening all the muscles in the body for a few seconds, and relaxing again. If you do this three to five times with intermediate periods of relaxation you will find your overall relaxation greatly improved.
All beginning students of yoga nidra are advised to take their lessons from a qualified teacher. Students should be aiming to gain a grasp of the technique sufficient to enable total recall of the instructions without any conscious effort, and the most efficient way to do this is by taking regular lessons and accompanying them with private practice. In the state of deep relaxation that is induced in all aspects of the practice, content, speed and sequence of instructions, tone of voice, are learned quickly and thoroughly because they are dropped directly into the subconscious mind, and are understood and absorbed on a deeper level than is possible by purely intellectual means. By itself an intellectual grasp of the practice is of little value and can in fact be an obstacle to its successful use.
A teacher knows the type of practice most suitable to a student's needs and can vary it accordingly. This applies to classes as well as individuals. If most people in a class start with a high state of tension then the technique will emphasize relaxation; if all relax easily and quickly then more progress can be made into a state of meditation.
Sleeping occurs commonly in yoga nidra as well as other types of meditation. Recent investigations by scientists (Science, January 23rd, 1976) have shown that experienced teachers of a form of mantra meditation popular in the west spent from 10% to 50% of their meditation time sleeping. When you are meditating by yourself it is easy to fall asleep without being aware of it, but in a class the teacher can help you remain alert by inserting admonitions such as 'no sleeping please'. On the other hand, people who suffer from insomnia will find the sleep they get in yoga nidra is very refreshing, arising as it does from a deeply relaxed state. If you fall asleep then your body clearly needs it, but if you stay awake you can develop your meditation practice.
If access to a teacher proves impossible a good alternative is to obtain a (cassette) tape transcription of a live class and play it back to yourself. Failing this you could put the instructions on tape yourself and by trial and error arrive at a reasonable presentation. If you do not have access to recording equipment then ask a member of your family to read the instructions to you aloud. In this fashion you will be able to make some progress.
The instructions should be given at a speed that keeps the mind busy but allows it to register each instruction and carry it out. This speed will vary according to the type of yoga nidra, or part thereof, that is being given, as well as the state of mind of the person doing the practice. Naturally beginners will need to be fed instructions at a slower speed than those familiar with the technique. Usually the 'rotation of consciousness' and 'rapid images' sections are given at a faster speed than the rest of the practice, whereas breath awareness may involve long pauses of five minutes or so. The first rotation of consciousness should be quite fast so as to capture the attention of minds still busy with the activities of the day; as relaxation develops these rotations can be slowed down. In general the timing of pauses becomes longer in more advanced practices.
Naturally, practices will need to be varied according to the time available and the capacity of the participants. It is more desirable to accomplish this by adding or subtracting whole parts rather than by varying the speed of delivery, once an optimum speed has been arrived at. The practices that follow have been set out to facilitate this kind of usage, and in addition provide a graded series of practices for each part or stage. The headings in bold type are included to describe stages of practice, and do not imply interruptions or long pauses by themselves; the appropriate pause is indicated by the last instruction in the preceding section.
Some of the more advanced practices included here may bring about a deep state of relaxation and meditation. It is very important that people are brought out of this state gradually and not abruptly. An indication that the finish has been too quick is when there are complaints of headaches. The mind is temporarily shocked by having to jump from one state to another. Similarly some people become frightened by the depth of their relaxation if they are brought out too quickly. In both cases the person involved should lie again in shavasana and practice awareness of breath until a state of calmness is achieved.
Care also needs to be taken in the selection of visualizations. The images used in these are often powerful symbols and can produce negative reactions in people who associate them with unpleasant experiences or phobias (irrational fears). Particular care should be exercised for example with images that evoke fear of Calling, fear of deep water, fear of burning to death and fear of being struck by falling or overhanging objects. Where such images are used it may be appropriate to insert reassurances. Although it is true that one aim of yoga nidra is to increase one's awareness of the contents of the mind, this should happen only gradually, not traumatically.
Lastly, it is especially important that teachers should avoid making negative value judgments, direct or implied, about students' experiences. If, for example, one person sees 'a warm and friendly darkness' in chidakasha whereas another sees 'garlands of lotus flowers', then both experiences should be validated. Similarly it will be obvious to most yoga teachers that statements of the type 'don't worry if you don't see this' must be stringently avoided during visualizations, as there is no surer way to start people worrying. Students should also be discouraged from idle discussion of their experiences in yoga nidra.