What is Deep Sleep: What It Is and Why It Matters?

You may run at the gym for thirty minutes to burn some calories. You might lift some weights or prepare a protein meal for dinner to build your muscles. But to be healthy overall, you may wonder what the best thing to do is.

You know that exercise and eating right are good for you, but do you realize sleep is crucial for your health, too? Just like various types of exercise and nutrients work together for health, you need different types of sleep.

Both Rapid Eye Movement (REM) and non-REM (NREM) types of sleep contribute to your physical and mental health. NREM sleep has 3 different stages, one of which is deep sleep. [1-3]

Read More: What is REM Sleep?

Today, sleeping deeply isn't getting any easier. The arrival of technology—in the form of tablets and smartphones, specifically—has only presented new challenges for recharging our bodies overnight.

While we often hear that the average adult should obtain anywhere from seven to nine hours of total sleep each night, the quality of our sleep (i.e., getting the right amount of deep sleep) is just as important.

What is Deep Sleep?

Deep sleep is the third stage of NREM sleep, so you may hear it called NREM Stage 3 or N3. In sleep medicine, deep sleep may be called slow-wave sleep (SWS), because your brain waves are the slowest at this stage.

Stage 3 NREM sleep, is an essential stage of the sleep cycle that facilitates physical and mental rejuvenation and is where you get your deepest sleep.

It may also be called “delta sleep” because delta waves are seen on the electroencephalogram (EEG). These slow delta waves indicate you’ve reached a deeply meditative and dream-free sleep.

It can be difficult to wake someone up when they are in the deepest stage of sleep. During this period, everything drops further: your heart rate, your breathing, your blood pressure, your muscle activity.

Deep sleep is most dense in the first half of the night, which happens right before our body drops to its lowest point temperature-wise.

It’s also important to note that this is the most restorative stage of sleep. If you consistently wake up not feeling refreshed in the morning, it is possible you aren’t getting enough deep sleep [1]

Did You Know: During this stage, brain activity is reduced, but studies have found that deep sleep contributes to memory, creativity [4], and insightful thinking. [5].

Why Is Deep Sleep Important?

If you're looking for one sentence that describes the importance of deep sleep, read this: Deep sleep helps your mind and body heal. It has vital power for us physically, including cell regeneration, a boosted immune system, bone and tissue repair, and so much more.

Ultimately, acquiring enough deep sleep lets you renew your energy levels to face every day.

Deep Sleep Statistic: Most adults should aim to get seven to nine hours of sleep at night [3].

Deep sleep is also associated with cognitive performance. Having a sluggish brain is a sign you're not getting enough. It's also tied to memory reconciliation. During the day, you don't organize your memories—this takes place at night while you sleep. [6]

Learn More: Discover the numerous benefits of maintaining a consistent sleep schedule and learn how it can significantly enhance your overall health and well-being.

Think about your memories as files on a desk. Getting enough deep sleep allows you to determine what memories are important and which aren't, effectively "clearing" your desk overnight. Obtaining deep sleep significantly affects both your short-term and long-term memory, which explains why lack of sleep has been associated with Alzheimer's disease. [7]

Deep Sleep Studies

A sleep study involves the clinical evaluation of sleep using polysomnography. This gold-standard procedure for determining whether or not you have problems with your sleep involves monitoring the activity of the brain, heart, lungs, and muscles.

Brain waves, monitored on an EEG (electroencephalogram), help specialists determine your sleep stage.

Today, sleep studies are completed only in clinic or sleep lab settings, but now home-based options exist.

How Much Deep Sleep Do I Need?

Now that you understand the difference between the sleep stages, we can discuss how much deep sleep is needed. The first cycle of deep sleep may last 20-40 minutes [3]. Experts say deep sleep should make up about 15-20% of your sleep time. So, if you sleep 8 hours, you should have 1-2 hours of deep sleep. [1-3]

Nevertheless, according to the Committee on Sleep Medicine and Research, how much you get will depend on your current sleep needs and age. [3]

They also reported a drop in deep sleep over time as we age. This occurs due to changes in hormones as the body produces lower growth hormone levels each year. Also, sleep patterns differ among women depending on their menstrual cycle or if they are pregnant.

Read More: How to Sleep Better When Pregnant

Tossing and turning during the night, waking up feeling tired, being easily awakened, and even getting up to use the bathroom are signs of disturbed sleep. If you have increased daytime sleepiness and changes in mood, you may not be getting enough deep sleep [7].

Lack of Deep Sleep Poor sleep quality generally contributes to health conditions, including obesity, mood disorders, heart disease, and migraines.

Loss of Deep Sleep Increase:

• High Blood Pressure
• Stroke or Heart Attack
• Alzheimer’s Disease or Dementia
• Type 2 Diabetes

Deep Sleep Statistic: Most adults should aim to get seven to nine hours of quality sleep at night [3].

How Does Deep Sleep Affect My Overall Health?

Now that you better understand deep sleep, the following occurs:

• Respiration, heartbeat, and eye movements decrease
• Muscles fall at ease
• Brain waves start to transition you from being awake to being asleep
• Your core temperature drops
• You can probably guess how restorative it can be

Some people struggle to wake up during this stage. But if a telephone, an alarm, or a barking dog wakes you from a deep sleep, you’ve probably felt confused and groggy due to the disruption.

Sleep Inertia

Ever get woken up from a deep sleep and find yourself confused? That initial state is called sleep inertia. It often happens when a person wakes unexpectedly or outside of normal sleep cycles. That “brain fog” can last for up to 30 minutes to an hour. [2]

Read More: Sleep Inertia: Current Insights

A lot happens during the deep sleep stage. Suppose you’ve ever had a rough night of sleep, tossing and turning, or experienced insomnia. You know deep sleep affects cognitive performance, especially your short—and long-term memory and your brain’s ability to absorb new information [7]. It's a necessary part of our sleep process, but deep sleep is only one factor of a good night's sleep.

How Do We Get More Deep Sleep?

Deep sleep is the most restorative stage of sleep, and it's essential for our physical and mental health. So, is there a way to improve our deep sleep? Yes, with 10 practical tips and tricks, you can learn more about how to get more deep sleep and start enjoying its benefits.

Find Your Deep Sleep Sweet Spot

How much sleep varies from person to person; it is based on ingrained habits and bedtime routines. It's important to listen to your body. If you are tired, don't fight it; go to sleep. But don't stay in bed if you can’t fall asleep within 20 minutes. Give one of the following a try if you can't fall asleep:

Can't Sleep, Do The Following

• Perform meditating exercises, such as Yoga Nidra
• Write your thoughts in a journal
• Listening to Calming Instrumental Music
• Read a book or magazine

Since deep sleep happens early, try half-hour increments to find the right time to go to bed. After that, seeing a sleep specialist might help uncover the problem if you're still struggling to fall asleep.

Key Takeaway: Getting more deep sleep is essential for your long-term health. Take every measure possible to ensure you're getting it consistently.

Final Thought

Learning the role of deep sleep, which goes beyond counting hours, can improve the quality of sleep. While exercise and nutrition are critical for overall health, deep sleep plays a role in physical and mental rejuvenation.

Understanding the importance of deep sleep, using tools like the Chiilipad, and adopting healthy sleep habits can transform your sleep into a powerful ally for health and well-being. Each step towards better sleep is a step towards a healthier life. Prioritize getting deep sleep and see how it can change so many parts of your life.