What happens in our brains when we sleep? For the longest time, this remained a mystery. It was assumed that sleep was when our minds and bodies shut down, but recent research has found the opposite.

During the day, toxins build up in your brain. Sleep plays a critical role in clearing them out, so wake up and get some sleep.

Your brain’s a complicated piece of machinery made up of approximately 100 billion neurons. These are special cells that send electrochemical signals to each other with every task and function you perform. At any given moment, one neuron can send a signal to thousands of others (source).

As the day progresses, every one of these cells produces waste, which accumulates the longer you’re awake.
It’s been well documented that the formation of new memories, as well as the shaping of new neuronal connections, occurs during sleep. Only recently has it been shown that sleep may serve a much more physiologically important task (source).

In a recent series of studies published by Maiken Nedergaard, a neuroscientist leading a team of sleep activity researchers at the University of Rochester, she reports that one of the most critical functions of sleep is actively flushing out the day’s accumulated toxins from the brain.
It’s similar to what occurs in your body during exercise. As your muscles tire and your energy depletes, toxic by-products begin to accumulate in your cells.

This is where the body’s lymphatic system comes in handy, clearing these toxins and sparing your body from any permanent damage. But the brain is outside this system’s reach, so how does its cerebral debris get flushed out?

Dr. Nedergaard suggests that the brain may have its own lymphatic system, clearing out toxins with cerebrospinal fluid. She calls it the glymphatic system, and while the idea itself isn’t new – it was proposed about a hundred years ago but lacked the necessary research tools – only now is it being scientifically proven to be crucial in maintaining a healthy brain (source).

The team also notes that this system is particularly active during sleep. While your body rests, the volume of space between your brain cells increases roughly 60%, giving the glymphatic system even more room to do the cleanup and making this system 10 times more effective when you’re asleep than when you’re awake (source, p.5).
So what does this mean for a chronically sleep-deprived society where the majority of people don’t get the 7 to 9 hours recommended by the National Sleep Foundation?

Even over the short-term – Netflix binge watching or the occasional all-nighter – our ability to pay attention and analyze information suffers. And while the human brain is relatively well-equipped to recover from this temporary stumble, a repeated loss of sleep is the equivalent of locking the cleaning crew out of the building every night.

When the cognitive trash is allowed to pile up, key neurons affecting cognitive performance, memory and more begin to degenerate. There is also a buildup of proteins that are normally cleared out during sleep.

One of the more notable of these proteins is beta-amyloid, which can form plaques in the brain strongly associated with Alzheimer’s Disease (source).

It’s a bad cycle. Less sleep leads to more daily stress. Our work suffers, we sleep even less and our brain isn’t given adequate time to clean up our mental garbage.

Thankfully, we have the power to break that cycle. By prioritizing sleep, we can give our bodies the rest they need to refresh, recharge, and revive themselves.

Start with setting and respecting a regular bedtime that gives you at least 7 hours of sleep a night.  If you still feel tired, add half an hour at a time. Still have trouble sleeping? Ask yourselves these questions:

• Are you on your phone or watching TV too close to bedtime? The blue light can impact your ability to fall asleep.
• Is the room too hot or cold? Humans tend to sleep better in slightly cooler environments.
• Does your partner toss and turn? Maybe it’s time to upgrade to a mattress with motion isolation.
• Is your mattress old? If your mattress is older than 5 years, it might be time to replace it.

When it comes to better brain health, getting better sleep is a no brainer. Wake up to your highest potential by prioritizing a good night’s rest.

Looking to lose some extra weight? Go to bed.

Google “best way to lose weight” and most of the results are based on two things: diet and exercise. Eat more greens, take the stairs, and so on. All good advice, but new research suggests there’s more to it than that. If you feel like you’re doing all the right things but are still struggling to achieve your goals, you may not be getting enough sleep. The recent consensus among experts is that adequate rest is just as important to your health (and weight) as what you eat or how many crunches you can do (source).

Losing weight overnight might not be possible, but along with diet and exercise, sleep plays a key role in maintaining a healthy lifestyle. When we cut our sleeps short, we’re disrupting the natural weight management processes that occur when we’re sleeping.

Here are 5 of our bodies’ natural weight management processes affected by sleep deprivation:

1 & 2. Leptin & Ghrelin Imbalance

Sleep helps regulate your appetite, which is controlled by two hormones: leptin and ghrelin. Simply put, ghrelin tells you when you’re hungry and leptin tells you when you’re full. Both need to be under control to maintain a healthy weight, but when you’re sleep deprived this is next to impossible. Studies have shown that sleeping less than six hours a night increases ghrelin production and decreases leptin, stimulating feelings of hunger but leaving you unable to tell when you’ve eaten enough (source).

3. Cortisol Jumps

4. Glucose Drops

One study found that going 24 hours without sleep reduces the amount of glucose going to the brain by 6%. Your body tries to replace that glucose in two ways – first, by looking for more in the form of that extra slice of cake, and second, by burning muscles that contain glucose. That’s right; when you’re sleep deprived, your body is far more likely to burn muscles and save long-term energy (also known as fat).
In another study published in the Annals of Medicine, a group of dieters were put on a strict diet and two progressively different sleep schedules. When their sleep was restricted to 5.5 hours a night, their fat loss was essentially cut in half from when they were allowed 8.5 hours a night, even though their calories remained the same. With less sleep, they also reported feeling hungrier and less satisfied after meals (source).

Insulin Spikes

When your body’s in sleep debt, it’s suffering from “metabolic grogginess,” a term coined by a group of researchers at the University of Chicago. They found that just four days of insufficient shuteye leads to a 30% drop in insulin sensitivity. Insulin, the body’s main anabolic hormone, is essential for absorbing blood sugar and either converting it into energy or storing it.
Is that bad? Kind of. When insulin resistance rises, your body pumps out more, which ends up being stored as fat. This can lead to diabetes, prediabetes, and a host of other health disorders (source).
If diet and exercise alone aren’t working for you, take a closer look at your sleep habits. The good news is, hitting the pillow a couple hours earlier than usual is way more inviting than doing another set of reps.

Consider sleep an active player in your health and fitness program.

Here a few ways you can sleep your way to a healthier weight:

• Shut it down. Say goodbye to all technology (phone, TV, internet) at least an hour before bedtime. The bright light is telling your brain that it’s time to be alert, so send it the opposite signal.
• Create a bedtime ritual. Take a warm bath, read, meditate; whatever helps you unwind and prep your body for rest.
• Skip the snooze. Trying to fall back asleep between alarms isn’t a good idea. It often disturbs your REM cycle, leaving you groggier than if you had gotten out of bed in the first place. Just set the alarm for a bit later.
• Stay on schedule. Try to go to bed and wake up at the same time every day. This helps set your body’s internal clock and improves sleep quality. Your body will also get used to the consistency, making you less likely to toss and turn.
• Create a restful environment. This usually means a cool, dark, quiet room. If you’re in need of a sleep environment upgrade it’s worth investing in blackout curtains, “white noise” machines, eye masks and ear plugs.

Even though sleep feels passive, it’s actually very active.  Wake up a healthier you by making sleep care just as important as diet and exercise.  Sure beats doing an extra set of burpees.

Have you ever stayed up late cramming for a test? Perfecting a presentation? Finishing a paper? Most of us have been there. Studies show, however, that we may have been better off by going to bed.

Studies on the links between rest and cognitive performance were being done as early as 1924, when American psychologists John Jenkins and Karl Dallenbach asked students to memorize lists of random syllables. The students’ memories were then studied one, two, four and eight hours later. They found that the longer the students slept between the learning session and the tests, the better their ability to recall more of the syllables (source).

A more recent study at the University of Exeter in the UK discovered that sleep almost doubles your chances of remembering previously unrecalled material, validating the theory that memory sharpens overnight.
Bottom line: If you’re staying up late cramming for an exam or presentation the night before, your chances of retaining that information are much lower with less sleep.

Simply put, while you rest, your brain is hard at work processing all the information you’ve encountered during the day and encoding them into memories. For this to happen, three functions have to occur:

1. Acquisition– the learning or experience of something new

2. Consolidation– the memory achieving stability in the brain

3. Recall – the ability to access that memory in the future

While acquisition and recall both occur while you’re awake, it’s now widely believed that sleep plays a crucial role in the consolidation of a memory, regardless of what type of memory it is. This new state makes the memory much less susceptible to interference (source).

A good night’s rest also requires the proper balance of both NREM (non-rapid eye movement) and REM (rapid eye movement) phases of sleep, as both play separate roles in the stages of learning and memory formation. At the University College of London, Professor Vincent Walsh explains that the slow-wave sleep (NREM) we experience earlier in the night is responsible for the consolidation of information we acquire that day, or declarative memory. This is the knowledge of fact-based information, like remembering what you had for lunch.

The brain spends the later part of the night in REM sleep, focusing largely on procedural memory. This is when we remember how to do something, such as play the piano. This is also the time when our brains perform subconscious creative problem solving (source).

The relationship between REM sleep and procedural learning consolidation, particularly involving sensory and motor related tasks, has been – and continues to be – the topic of many recent studies. One study involving the testing of finger-tapping saw people split into two groups. After training, both groups were tested with or without intervening sleep. The group that was allowed to sleep displayed a post-training increase in both accuracy and speed; the group that stayed awake showed no signs of improvement.

It is also currently being hypothesized that REM sleep additionally plays a role in declarative memory processes if the information is more complex. For example, individuals engaged in an intensive language course experienced a marked increase in REM sleep (source).

These results all give further validation to the synaptic homeostasis hypothesis of sleep, developed in 2003 by scientists at the University of Wisconsin-Madison. This hypothesis, known simply as SHY, seeks to explain why our brain needs rest after a day spent learning new information. During waking hours, as we saturate our brains cells with information we strengthen the synapses that form connections between those cells. It’s an exhaustive process, but sleep allows the brain to consolidate those memories (source).

Christoph Nissen, a psychiatrist at the University of Freiburg, conducted a series of tests on both men and women, either after a night of sleep or a night without sleep. In the initial round, Nissen used magnetic pulses to make neurons fire in the volunteers’ brains, causing a muscle twitch in the left hand. When performed on the sleep-deprived group, a far weaker pulse was enough to elicit a muscular response.  The implication is that a sleepless brain is in a more excitable state, with a stronger connection between neurons.

Nissen then used brain stimulation to mimic the firing of neurons that occurs during the consolidation of memories. The neurons were much less responsive for those in a sleep-deprived state, suggesting that the wiring of new memories into the brain is impaired by sleep loss.

When considered together, the test results suggest that rest allows brain activity to quiet so memories can be consolidated.  The sleep-deprived group, by contrast, showed a level of electrical activity that notably blocked the formation of new memories (source).

So what happens when we try to get by on less sleep? Not only are we less able to focus and receive information, but our strained neurons can no longer coordinate information properly, and our faculty for accessing previously learned information becomes largely impaired.

Sleep deprivation doesn’t just hurt your memory – it can also make you more susceptible to false recall and manipulation. In one study, participants who got less than 5 hours of sleep a night were much more likely to claim they had seen a news video they hadn’t than their well-rested counterparts. They were also more likely to incorporate false information given to them by the researchers into their own personal recall (source, p.107)

So the next time you’re tempted to burn the midnight oil, ask yourself – is it worth it? Maybe not.