Sleeping is an incredibly important component in the average person’s efforts to manage stress. During times of heavy stress, the need for sleeps rises. When you are sick, you need to sleep more than you do when well. Children whose bodies are growing and changing are under stress associated with growing up. They need more sleep than the average adult. When you don’t get enough sleep, your performance lags, you become more irritable, and your ability to concentrate diminishes. These are all signs of someone who is under stress, because they are not sleeping enough to restore proper balance.
The average amount of sleep an American gets has dropped from 9 hours to 7 hours in the last 100 years. What is happening in our society is that sleeping is being replaced by other activities. Many are simply more profitable for corporations, such as playing video games or watching TV, and are pushed relentlessly by advertising and other facets of mass media. Others are outgrowths of the increasing competitiveness of society which creates high levels of psychosocial stress and pressure, such as staying up late studying. We are not accounting for the quality of the time we are awake. Instead, we have focused on the amount of time we are awake. This is having disastrous consequences. As one author has put it:
Over the last hundred years, we have intruded upon a delicate and finely regulated process perfected by several hundred million years of evolution.
One study showed that in subjects who get only four hours of sleep per night for several nights, the activity of the sympathetic nervous system (the system active during stress response activation) is increased and the vagal nerve tone (the nerve that controls much of the activity that occurs during relaxation) goes down. In addition, evening cortisol (a main stress response hormone) levels and evening blood glucose (the fuel for movement liberated from cells during stress) levels are elevated in the sleep deprived – all of which lead to homeostatic load. When the subjects are allowed to get 10 to 12 hours of sleep a night, the signs of homeostatic load disappear.
Sleep is needed not just directly to reduce the effects of stress, but also indirectly to manage stress. Sleep is crucial for proper brain function, and good brain function is necessary for the homeostatic balances of the body to function properly. If they function improperly, resiliency is lost. Exactly what sleep does for us is in debate; but all researchers believe it is crucial to brain functions.