Good sleep is a staple of good health. Sleep is needed to regulate body functions, help you feel more energetic, happier and better able to function. Sleep just feels good. Compare sleep to eating. When you are hungry you consume nutrients to help bodies grow, repair tissues and provide health to your internal organs. It is easy to grasp the role of eating; but a bit more difficult to determine why we need to sleep.
Think of sleep as an activity regulated by internal drives. If you go without food you have an uncomfortable sensation of hunger, pain and general sluggishness. If you go without sleep you feel overwhelming tired; it is hard to keep eyes open and brains working. Sleeping relieves these symptoms and helps the body to stay on task.
Scientists have developed theories of sleep that might just explain why we sleep. One theory is:
Survival Function Theory can also be called the adaptive or evolutionary theory. Inactivity at night is a survival function. Animals use it to keep out of harm”s way or as a survival function. Scientists suggest animals that stay quiet during periods of vulnerability have an advantage. They do not experience accidents during sleep mode and are generally not killed by predators. You, on the other hand might be highly paranoid and counter by saying it is safer to remain conscious to react to an emergency. If safety is your paramount reason for not sleeping, the survival function theory can be discounted.
Living in highly functioning societies where food is plentiful, takes away the ” “hunting at night instinct” . However sleep is still necessary to reduce energy demands and expenditures during the period when it is hard to ” “search” for food. Energy is significantly reduced during the sleep portion of your life by as much as 10 percent. Body temperatures and caloric demand decrease while you sleep. One of the primary functions of sleep, therefore, is to help you conserve your energy resources. This can also be connected to the inactivity or survival function theory or hunt in the day and lay low in the night.
We sleep to restore what we lost while awake. Sleep is the opportunity for the body to repair and rebuilt cells. Scientific studies have shown that you can lose all immune functions without sleep. Animals that are deprived of sleep often die in just a very few weeks. Muscle growth, protein production, growth hormone release and tissue repair occur when you are sleeping. If you are an insomniac, you will find that your body gradually becomes weaker.
Specific rejuvenation functions are specific to the brain. While you are awake, neurons in your brain produced adenosine or a by-product of cell functions. As you build up adenosine in the brain you begin to feel tired. This occurs at the end of activity or the passage of time. You can use caffeine to block the adenosine in the brain, but this only works for a short period of time. Researchers believe that the build-up of adenosine while you are awake promotes the need for sleep. When you are awake adenosine accumulates and stays high. When you sleep, your body is able to clear away adenosine from your brain and system. This helps you feel alert and ready to work through the day.
Scientists who study the brain note sleep is necessary to correlate changes and bring organization to the brain. Brain pliability and sleep plays a crucial role in the formation of learning for infants and young children. Most infants spend about 13 hours a day sleeping and almost half of that time is spent in REM sleep. This is the stage where dreams occur and memories are cemented. This same link between sleep and bran pliability is very clear. Without sleep, you lose the ability to perform tasks, learn, and remember.
One very interesting observation determined by sleep studies: if you get the necessary amount of sleep after you have learned a new skill, your brain will remember that skill and you will improve performance. Basically, the quality and quantity of sleep has a profound impact on learning, memory and body functions. If you are sleep deprived it is almost impossible to optimally focus and you will have difficult times learning.