Theories, Purposes, and Functions of Catching Zzz's

Though it is extraordinarily commonplace, there is much about sleep that remains a mystery. And, while we all spend one-third of our lives doing it, there is still no universal agreement regarding the singular purpose or function of sleep. Only in the last few decades have we even begun to unravel sleep's true secrets. However, there are at least three common theories as to why we sleep, but it is unknown which (if any) are in fact correct.

Restorative Theory
The restorative theory of sleep is the most accepted explanation for why we sleep. It suggests that sleep restores tissue and prepares our bodies for the next day. This may involve clearing accumulated neurotransmitters from our brain as well as other tissue repair that occurs throughout our bodies. More specifically, the glymphatic system flushes chemicals from the brain during sleep, including adenosine, the substance largely responsible for increasing levels of sleepiness during wakefulness.

Adaptive Theory
This alternative explanation suggests that sleep increases our ability to survive. As nighttime can be dangerous—especially in animals at risk from predators—it makes sense to seek a safe refuge. By avoiding dangers, the animal lives longer and is more likely to reproduce. Thus, sleep becomes an adaptive advantage. When morning light returns, it is a powerful stimulus for wakefulness, further preserving the evolutionary advantage of responding to the natural day-night cycles.

Energy Conservation Theory
Others theorize that sleep is a means to conserve energy. In a sense, by sleeping we are able to spend part of our time functioning at a lower metabolism. Thus, our overall caloric needs are reduced. If that time were spent awake, we may not have enough food to survive. It also allows time to create glycogen, an energy store that is used as the brain's fuel reserve.

Though metabolism slows during slow-wave sleep, the brain is extremely active during rapid eye movement (REM) sleep, therefore not fully accounting for the conservation.

Florida lawmakers want to keep the clocks consistent all year. Here’s why that’s great news for your body and mind.

Lawmakers in the sunshine state just voted in favor off the Sunshine Protection Act, a bill that would keep clocks on Daylight Savings Time year-round. (The bill needs to be signed by Florida Governor Rick Scott and approved by Congress before it’s made into law.)

The bill has its critics; it would put Florida an hour ahead of the rest of the East Coast for half the year, which could cause logistical headaches for things like television schedules and aviation timetables. But let’s face it: It sure would be nice to stop having your sleep messed with twice a year, wouldn’t it? And, as it turns out, nixing the lose-an-hour/gain-an-hour cycle could actually brighten up your overall health in a few big ways:

Your mental health may get a boost
People are less happy overall the week after Daylight Savings kicks in, research shows. What’s more, the number of people seeking help for depression spikes 8% immediately following the shift from Daylight Savings Time to Standard Time every fall, according to a 2016 study published in Epidemiology. Researchers aren’t totally sure what triggers the increase, but believe moving the hour of daylight from evening to morning makes cold, dark days feel even shorter.
It could cut your stroke and heart attack risk
The sudden addition or subtraction of an hour to your day messes with your circadian rhythm, also known as your internal clock that controls your sleep and energy. As a result, research shows there’s an uptick in heart attacks the day after a time change, and an increase of stroke in the two days following.

It could even impact your ability to conceive
A 2017 Boston University Medical Center study revealed the shift to Daylight Savings Time contributes to higher miscarriage rates in in vitro fertilization (IVF) patients. More research is needed to confirm these preliminary findings, and it’s unclear whether the time change affects women who are trying to conceive naturally. Still, the results are eye-opening.

And, obviously, you’ll sleep better
It’s harder to fall asleep, stay asleep, and log the expert-recommended 7 to 9 hours of shuteye for at least a week following a time change. So if the clocks were to stay consistent year-round, you’d get two extra weeks of solid sleep. An extra hour may not sound like much—but when you wake up March 11 groggy and droopy-eyed, there’s a good chance you’ll want it.