Friday, July 12, 2013

How much Sleep do you need?

Good question...and surprisingly, there really isn't a "right" answer!  We've always been told that we need 8 hours to feel rested, but would you be surprised to hear that this may be bad for you?  Getting less than 8 hours may actually be ideal!  The CDC prescribes the following:


But honestly, I find this a water-downed version of the truth.  7 to 9 hours is a HUGE range for adults!  And sleep is highly correlated to health.  You sleep too little, you have health issues.  You sleep too much, you have health issues.  If nothing else, remember that a bad sleep cycle affects more than just your energy level the following day!

Let's see....whats wrong with sleeping too little?
  • Your level of leptin (appetite-regulating hormone) falls, thereby encouraging an increased appetite
  • Require more food to keep awake!  Its a fine line....if you are tired, you will crave anything that will give you extra energy.  That soda?  Down it.  That carb-laden snack?  Consume it.  You need the instant energy, because without that pick-me-up, you will fall asleep.
  • Correlation between little sleep and high blood pressure and cardiovasular problems (typically correlated with those that sleep 5 hours or less)
  • Correlation with obesity, diabetes, depression, alcoholism and auto accidents.
  • Sleep deprivation directly affects the parts of your brain that control mood and concentration.
What's wrong with sleeping too much?
  • Spending excess time in bed can be a sign of depression or chronic fatique syndrome.  And these two conditions have a correlation to obesity.
As you can see, the risk of not sleeping enough tends to be more than sleeping too much.  Maybe this is why the CDC errs on the high side?

So, if sleeping too much and sleeping too little is bad for you?  How much sleep should you get?  Its so personal, and you need to devote some time in trying to understand your own ideal sleep/wake cycle.   You can google various studies, but it appears that most indicate that sleeping 6.5-7.5 hours/night live the longest, while people who sleep less than 6.5 or more than 8 do not live as long.  So, for an average night, try to get out of bed before 8 hours and try to stay in bed for at least 6.  Diabetes also tends to be the lowest for those sleeping around 7 hours/night.

That being said, there is no one "right" answer, and nobody knows how to perfectly determine that, as it may simply change over time (you may have needed 6 hours when you were 30, but now need 7 hours when you are 50, or vice versa). But, the importance of keeping an eye on your sleep remains an important, and quite simple, exercise.  If nothing else, understand what sleep is!

The "normal" human sleep cycle averages 90 minutes, in 5 stages:
  • Stage 1 - drowsy and light dreams (normal is 5% of total sleep time)
  • Stage 2 - light sleep (normal is 50% of total sleep time)
  • Stage 3/4 - delta/deep sleep (normal is 20% of total sleep time)
  • Stage 5 - REM or deep dream sleep (normal is 25% of total sleep time)
Now, unless you brain gets hooked up by a medical specialist, you will likely never know exactly what type of sleep you are getting.  Its been said time and time before though that a human cannot live without REM sleep.  Sure, its stated, but why can't we?  Sleep is uncharted territory in the medical profession, so take everything with a grain of salt.

So, what can you do?  Assuming you do not have an actigraphy device, track your time in bed and rate your sleep, as well as the following day's mood.  Do this for a few weeks and see if you can see a trend.  This may be all it takes to determine your personal sleep/wake cycle.  If you think you have a sleeping disorder (insomniac), you may simply be asking your body to rest longer than it needs....wouldn't that be a nice problem to have.

Seriously, what can you loose?  Personally, I seem to need 7-7.5 hours of sleep, while my husband requires about 6-6.5.  I would love to have that extra hour every day, but I know my body simply needs more time to rest.  I'm ok with that, and he is as well...as he knows I am not a pleasant person to be around if I am tired.

1 comment:

  1. I seem to function best on 8.5-9 hours. I wish I could get away with 7 every night! But I get sick if I have too many nights in a row less than 8. It's like clockwork. Like you said, it's about knowing your body and making sure you do what's best for it.

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