Religious devotees and spiritual aspirants throughout the world have tried to experience a divine revelation through various extreme practices that put the body under severe stress. One of these practices has been extreme fasting, and another, the attempt to overcome the power of sleep and carry out long vigils and prayers overnight. There is no doubt that in extremis the consciousness can shift out of the normal frame and may open to experiences that are not part of the normal daily outward-facing consciousness. Yet at the same time, when carried out to such extremes, particularly if this is done repeatedly, the basic physical underpinning of the body can be compromised, and the result of this kind of rajasic action is a rebound into a tamasic status, which is not helpful for spiritual development.
A sattwic, clear understanding of the body and its functioning, and a method that does not do harm to the body, but supports it as a stable basis for spiritual practice, seems to be the most advantageous approach. It is interesting to note that for the practice of Raja Yoga, it is recommended to gain a ‘seat’ (asana) which is comfortable and not too relaxed nor too hard, in a place that is not extreme as to heat, cold or wind, etc. The significance of this is that spiritual growth has the best chances of developing if one treats the body as a partner not an opponent that needs to be forced into submission.
In the integral yoga, the idea is to shift the focus away from fixation on the body-life-mind complex toward the spiritual consciousness. The more one tries to dominate, control and then respond to the reactions that occur when this is tried, the more one remains fixated on this outer nature and thus, one is defeating the purpose.
Sri Aurobindo observes: “This is not a yoga in which physical austerities have to be done for their own sake. Sleep is necessary for the body just as food is. Sufficient sleep must be taken, but no excessive sleep. What sufficient sleep is depends on the need of the body.”
“The normal allowance of sleep is said to be 7 to 8 hours except in advanced age when it is said to be less. If one takes less (5 to 6 for instance) the body accommodates itself somehow, but if the control is taken off it immediately wants to make up for its lost arrears of the normal 8 hours. So often when one has tried to live on too little food, if one relaxes, the body becomes enormously rapacious for food until it has set right the credit and loss account. At least it often happens like that.”
Sri Aurobindo, Integral Yoga: Sri Aurobindo’s Teaching and Method of Practice, Chapter 10, Difficulties in Transforming the Nature, Sleep, pp 311-314