Human beings spend almost half of their lives asleep and many people view this as a waste of time.
However, it has been proven time and time again that constant good sleeping patterns are not only good for ones physical health, but also for ones mental well being.
There are a number of theories on why this is, below are some of the more plausible.
The Inactivity Sleep Theory The inactivity theory is one of the oldest theories on why we need sleep.
It is also sometimes referred to as the evolutionary sleep theory and states that sleep in an adaptation of the species that helped it survive and thrive.
It did this by keeping it out of harms way in times of vulnerability, such as at night.
This theory went on to suggest that animals that stayed still for long periods of time were more likely to survive during periods of darkness as they were less likely to suffer injury or death.
Because of this higher survival rate the sleep trait became a prevalent one in species thanks to survival of the fittest.
This theory, however, has been debunked by the simple fact that it would have been safer to simply stay awake and be able to react to an emergency situation.
It is simply not to any species advantage to be asleep in a situation where safety and a good reaction time is important.
The Energy Conservation Sleep Theory This sleep theory is closely related to the inactivity theory in that sleep is also seen as an evolutionary advantage that developed over time to help with the effective use of energy when humans still did not have a regular or consistent source of food.
Therefore, the energy conservation theory suggests that the main function of the sleeping process is to reduce a person's energy demand.
It did so at night as this was the least efficient time to search for food.
There seems to be a fair amount of medical evidence that supports this theory however, as human metabolism decreases by as much as 10 percent in humans during sleep, lending credence to this theory.
The Restorative Sleep Theory Another sleep theory that has been gaining favour over the last few decades is the belief that sleep helps to "restore" the body.
It gives the body time to repair and rejuvenate itself and this is supported by a number of facts collected in both human and animal sleep studies.
In fact, humans and animals that are deprived of sleep entirely can die from the loss of all immune function.
This loss of immunity is directly linked to sleep deprivation.
It can, therefore, be seen that humans need sleep to survive.
Sleep and sleeping is a natural process that keeps us healthy both in mind and body and is an integral part of human existence.