How we Sleep

It's always intriguing to hear the latest survey related to sleep.
And they all have one thing in common, and that is people are much better off getting the recommended hours for healthier living.

That doesn't come as anything new but what are the prescribed hours we should be sleeping each night and what actually happens when we lay down and close our eyes every night.

Sleep for human beings is divided into two distinct states; "REM" (rapid eye movement) also called light or active, and "NREM" (non rapid eye movement), also called deep or quiet sleep.

When adults fall asleep we generally slip straight into NREM sleep.
Our bodies become motionless, breathing (becomes) is shallow and regular, our muscles relax and for all money we (are) become "out to it".

After about ninety minutes our brain begins to "wake up" and starts functioning on a different level, this is when we enter REM sleep.

During REM, our brain, it could be said, "exercises", we dream, fidget, roll over, moan and talk in our sleep, even adjust the blankets without fully awakening. When we wake during the night, either for no apparent reason or to go to the bathroom it is from this REM state.

The average adult during a normal eight hour sleep takes on average seven minutes to fall asleep and spends around two hours in REM sleep and six hours in NREM sleep, rotating between the two states about every ninety minutes.

Infants on the other hand, especially young babies, enter sleep through an initial twenty or thirty minutes in REM.

This explains why a lot of people especially babysitters and people unfamiliar with babies sleeping patterns go to painstaking, meticulous and sometimes bizarre lengths to get baby off to sleep - only to have her suddenly wake when it looks like the "deals done".

If efforts were to continue for an extra twenty or thirty minutes until baby has entered NREM sleep, there is a far greater chance that baby will stay asleep.

One would recognize the transition from REM to NREM sleep. Spasmodic twitches, muscle tightness, grimaces and even sleep grins would gradually give way to an overall limpness with breathing becoming more regular and shallow. If baby needs to be moved it's better to wait for her to reach NREM state as she can be easily woken whilst in REM sleep.

Young babies spend approximately half their sleeping time in REM, dropping off to about twenty five percent by the time they reach four years of age. Infants sleep cycles occur about every sixty minutes (that is going from light sleep to deep sleep then back to light sleep).

Although it might seem like the ultimate wish come true when we hear about a young baby sleeping through the night, new research is showing that this might NOT be in the best interests of the baby.

Here's why.

Babies are at their most vulnerable when they are very young. Their cardiopulmonary regulating systems are not developed enough to cope well with self arousal from long spells in NREM.

Alternating frequently between REM & NREM stops a baby from falling too deeply for too long into deep sleep from which she might not be able to self wake.

This is one of the main theories behind the incidence of SIDS.

Secondly, blood flow to the brain nearly doubles during REM sleep and researchers theorize this is because this is the time when the brain develops.

Learning is thought to occur as the brain processes information that was acquired while awake.

This is further reinforced by the fact that premature babies spend almost ninety percent of their sleeping time in REM - to protect themselves from falling into a deep state of sleep for too long and to help speed up their brain development.

A young baby has a very small stomach (slightly larger than her fist) and because she digests breast milk very quickly it is unlikely that she'll sleep for more than four hours, and most likely not for more than 1 - 2 hours between feeds

After six months babies cardiopulmonary regulating systems have developed to the point where their bodies are better able to cope with longer periods of deep sleep and thus the risk of SIDS drops dramatically.

Adults need between 7 - 8 hours of sleep per day for peak condition. Adolescents need nine and a quarter hours per day, yet American adolescents average only seven and a half hours with up to 25% surviving on six and a half hours.

No wonder why they struggle to get out of bed most mornings and struggle with concentration during school!

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