Any machine which works continuously throughout the day without rest becomes heated. The body is also a machine. Sleep is a cooling device. It recharges the batteries of the body which have been discharging energy during the whole waking state. Energy expended in one’s daily work is recouped. A good sleep is necessary for the whole organism. The metabolic functions are revitalized, energy levels are restored and the mind-body is allowed to rest. Sleep is essential for optimum health.
A good sleep leads to a vast increase in both physical vitality and mental concentration. One is able to do twice as much work in half the time. Moreover, the work will be far better.
Sleep should be, and generally is, a simple process. One merely goes to bed, lies down, closes the eyes and . . . sleep. This is how the process should be, and it certainly is like this with animals. But for humans in this busy modern world, it is often not the case. Many spend hours trying to sleep, and when they do sleep, they are racked with tension, tossing and turning. The mind remains full of anxieties and disturbances. The body and mind are not rested. Many people wake up feeling more tired than before sleep.
Good, regular sleep is essential. About one third of our life should be spent in sleep. Deprivation of sleep leads quickly to psychosis, hallucination and disorientation, as well as psychosomatic disorders. This has been tested by scientific experiments. So make sure that you obtain sufficient deep sleep. If necessary you should learn the art of sleeping. One method is to utilize yoga nidra.