We’ve heard the recommendations: try to get the seven hours at least of sleep per night to stay healthy.
But here's the thing: we still don't know exactly why that is.
Sleep research is relatively new.
Researchers only discovered rapid eye movement (REM) sleep in the 1950s, and only started studying rest and how our circadian rhythms work in the 80s.
There's still a lot left to learn. "We know it helps our immune system.
We know it helps our brain so that way the next day we're alert and awake and we're ready to perform again and it's helping our memory and things like that.
But how it does some of these things is an unknown," says Ken Wright, the Director of the Sleep and Chronobiology Lab at University of Colorado Boulder.
Wright and his fellow researchers have been studying how sleep works: the effects of shift work on sleep, sleep deprivation on metabolism, and what it takes to reset your circadian clock.
The team says they've learned some major lessons so far. "If you can't get a full seven hours in one sitting.
So let's say someone could get only five to six in the day.
When they come back from work, taking another two hour nap later in the day, before going back to the work shift to increase that total 24 hours sleep time, is probably gonna be beneficial," Wright told Newsy.
"If you're not getting enough sleep, you can actually lose more muscle mass and sort of maintain your fat mass.
Which again could contribute to, sort of you know, perhaps negative metabolic consequences.
Even if you are losing weight," said Christopher Depner, an integrative physiology researcher at the lab.
"Whereas if you are getting enough sleep to you're meeting that adequate seven hours per night you're going to actually tend to lose more fat mass and maintain your muscle mass which would be a more desirable sort of metabolic profile." SEE MORE: You Can't "Recover" Lost Sleep On Weekends, New Study Says "When we don't get enough sleep or if we someone has a sleep problem that's not treated this has health consequences and increasing the risk for things like heart disease, obesity, diabetes, mood problems and things with drug abuse, for example.
And so we now are going to be seeing sleep be important for medical treatments.
In the future, we're going to see that if we treat sleep problems, the other health problems that people have are likely to also get better.
So I think we have an opportunity here now to harness really the power of sleep for our health," Wright said.
Wright says scientists have discovered how light impacts our sleeping habits and body rhythms too.
Blue light, research has shown , has adverse effects on sleep.
But lighting can also be beneficial, in some instances.
For example, children in schools with enhanced sunlight pay more attention .
In hospitals, more light in a room helps speed up recovery and reduces the use of pain medications. Inside the sleep lab, researchers showed the steps that subjects undergo at the beginning of a sleep study.
Scientists hook up an EKG and glue more than a dozen electrodes onto a subject's scalp and face, to measure everything from eye movement to how much they grind their teeth. Technology is also helping sleep research evolve beyond stand alone labs like the one at CU Boulder.
At-home devices and smartphones can help study chronic sleep problems -- which the National Sleep Foundation says affect 50 to 70 million Americans each year.
One thing sleep scientists know for sure so far: there's no shortcut for fixing that problem.
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"There's nothing that replaces sleep right now," Wright said.