Day 15 of 31-Day Series “Your Last Health Resolution”

You’ve heard it often:  “You should get at least eight hours of sleep a night.”  Is it true?  What is a sleep cycle, and what does your body need to function at an optimum level?

Woman SleepingScientists have been uncovering some powerful truths associated with sleep.  According to the research, we learn more effectively when we’re snoozing than we do when we’re awake.  The rest enables our brains to process what we spent the previous day learning.  (That makes me rethink my all-night cram sessions before finals in college.) 

One study presented participants with a complex math problem.  After practicing it 100 times, they were sent away and told to return in 12 hours.  Over time, many participants discovered a simpler solution to the problem.  The main difference between those who figured it out and those who didn’t?  Sleep.  Those who slept between sessions were 2 1/2 times more likely to solve it.  (That affirms my strategy of sleeping through a few classes.)

So How Much Sleep Do You Need?

On average, Americans sleep about 6.7 hours a night.  Not quite enough.  Most adults need between 7 and 8 hours (and teenagers need about 9). 

The average person moves through a sleep cycle roughly once every 90 minutes.  The cycle includes two basic states: rapid eye movement (REM) sleep and non-rapid eye movement (non-REM) sleep.  Non-REM sleep has 4 stages. 

In stages 3 and 4 of non-REM sleep, the body repairs and regenerates tissue, builds bone and muscle, strengthens the immune system.  The body also secretes hormones, like growth hormone and prolactin, during sleep.  So if you plan on building muscle, you need quality sleep!

How important is it to get the right amount?  Research shows a 35% greater chance of substantial weight gain for people who only sleep between 5 and 6 hours, and a 25% greater chance for those who sleep between 9 and 10 hours.  Lack of sleep can also increase your risk for type 2 diabetes, depression, impaired memory and cognition, and premature death.

How about power naps?  Researchers say they do help with cognition.  But they can’t replace the regenerative aspects of deep sleep.

For those of you with smartphones, you can use Sleep Cycle Alarm Clock (iphone) or Sleep As Android (android) to monitor your sleep cycles.

I’m powering down before I head to bed.  Sleep well tonight.