Understanding sleep for healthier living and getting the job
done
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 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 NEM 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 for not 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 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!
Average Ideal Sleep Times
Newborn 16.5 hours 12 months 14.5 2 years 13 5 years 11 10 years
10 16 years 8.5 20 +years 7-8