If you have done any sort of reading on sleeping, you’ll come across this term: deep sleep. After all, the term just pops up everywhere — on the Internet, in scientific journals, and more.
But, just what exactly is deep sleep?
Does that mean that the sleep is philosophical and oh-so-very profound? Or, perhaps it means that the sleep is extremely immersive and gripping? Maybe it just means that there’s no waking up from this type of sleep?
Aicks! By the looks of things, it’s time to find out a little more about deep sleep. Well, you’re in luck because today we’re talking all about deep sleep. Everything from what it is to the importance of deep sleep.
Brace yourself, we’re in for a ride… into the abyss of deep sleep.
What is deep sleep?
First things first, we have to tackle the question of what exactly in the world is deep sleep?
Well, deep sleep is one of the stages of non-rapid eye movement (NREM) — the last stage, actually. That’s why it’s also known as N3. Besides N3, deep sleep is often referred to as slow-wave sleep (SWS) and delta sleep as well.
During this stage of sleep, your body is extremely relaxed. You most probably won’t wake easily. Yes, even when the alarm is going off. But, if you do wake up from deep sleep, you likely will feel very groggy.
At this sleep stage, your body is experiencing a multitude of changes. This includes things like slower heart rate and breathing, cellular repair, cellular growth, and more. Your brain waves are also at the slowest that they’ll be.
Deep sleep takes place for longer periods during the first portion of your entire sleep. So, the longest period of deep sleep will usually occur just a little while after you fall asleep. Say, somewhere from about 30 minutes to 45 minutes after falling asleep.
Typically, the deep sleep stage can last anywhere from 45 to 90 minutes for most people. Each sleep cycle will see a shorter duration until it stops. Some people will need more deep sleep than others to feel rejuvenated. Meanwhile, others simply don’t need as much deep sleep.
But, either way, there’s simply no denying the importance of deep sleep. Do you need further convincing? Not a problem! Let’s zoom in on why you need deep sleep.
Deep sleep replenishes energy
Contrary to popular beliefs, your brain is actually still working hard when you’re asleep. Sure, the brain waves (and activities) increase and decrease based on your sleep cycle but, ultimately, the brain is still in an active state.
With deep sleep, the brain waves have what’s called slow oscillations. And, in a 2010 study in The Journal of Neuroscience, the researchers concluded that “sleep is for an energy surge” during these slow oscillations.
According to the study, the surge nourishes and allows anabolic, restorative processes, such as protein and fatty acid synthesis to occur.
To put it simply, deep sleep helps to repair the body and stores a surge of energy for the next day. So, be sure to thank deep sleep if you feel particularly energetic tomorrow.
Deep sleep helps with memories
Deep sleep is also known to help to reorganize your memories. But… how? Well, according to experts, this is likely due to synaptic homeostasis.
Here, the theory is that the brain frees up space and energy while you’re in the deep sleep stage. So, you remove all unnecessary synapses. If you need a little refresher of your Biology lessons, synapses are essentially those small spaces between two cells, where they can pass messages for communication.
Meanwhile, a lack of deep sleep is often thought to cause memory problems — especially in older people. See, those who don’t get enough deep sleep have higher levels of tau and beta-amyloid.
These are proteins in your brain that are often linked to diseases like Alzheimer’s and dementia. Deep sleep is thought to get rid of these proteins.
Deep sleep helps with learning
For most of us, when we take in new information, we store it for a short time. So, this is everything from the lyrics of the new K-Pop song to a new language to a moment from date night. This is called encoding.
And, this is where deep sleep comes in. Deep sleep helps to strengthen these memories. What this does is that it will help you recall them later.
This is what is called an active system consolidation. Let us explain how it works. Here, the slow oscillations of deep sleep help to boost the communication between the hippocampus (the part of your brain that stores your recently acquired memories) and the cortex (where you store long-term memories).
Ah, just one of the many wonders of deep sleep!
Zooming out
If there’s one thing that we hope you get from this article, it’s the importance of deep sleep. And, if you would like some more guidance on the topic, we have a helpful article on how to improve deep sleep.