Understanding Deep Sleep

Tara Youngblood Aug 09, 2022

What is deep sleep?

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’s the best thing to do.

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

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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.

As advocates of a deeper night’s sleep, we’ll explore the following:

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.

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. [1-3]

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].

Deep Sleep

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 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]

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]

Getting more deep sleep

Sleep Studies

A sleep study involves the clinical evaluation of your 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 help sleep medicine specialists know what sleep stage you are in by monitoring your brain waves on an EEG (electroencephalogram). [2]

Today, sleep studies used only to be completed in clinic or sleep lab settings, but now there are home-based options.

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 that deep sleep should make up about 15-20% of your total sleep time. So, if you sleep 8 hours, then you should have between 1-2 hours of deep sleep. [1-3]

Nevertheless, according to the Committee on Sleep Medicine and Research 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.

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].

Not Enough 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 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 is going on during the deep sleep stage. Suppose you’ve ever had a rough night of sleep, tossing and turning, or experiencing insomnia. You know deep sleep affects cognitive performance, especially for 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.

Energized with deep sleep

How Do We Get More Deep Sleep?

Let’s discuss some ways to increase the likelihood of getting enough deep sleep and how to improve it. Since temperature drop is a crucial part of the deep sleep stage, finding ways to activate that “sleep switch” can help improve your levels of deep sleep.

Deep Sleep Statistic: The amount of deep sleep you need varies by age [3]. Whether you get that amount may be related to other characteristics like gender and race [8].

Sleeping Cooler at Night

Whether you’re cooling a room or using a bed system such as the Dock Pro Sleep System, sleeping cold can help achieve deeper sleep. They can kick start that temperature drop once you’re already under the covers.

A significant change in your body temperature—even if it’s only .1 degrees—goes a long way toward making sure you sleep deeper for longer.

Limit the Amount of Caffeine

This may be difficult for some but try to avoid coffee seven hours before bedtime. As a stimulant, caffeine makes it more challenging for some to fall asleep. It also reduces the amount of deep sleep you receive. Before bedtime, drink water, tea, or other non-caffeinated drinks. [9]

This may not be appealing as coffee, but warm milk and chamomile can help induce sleep.

Regular Exercise Routine

As we mentioned at the beginning, exercising can build muscles and burn calories. It is fantastic for your mind and body. Exercise can help you sleep better, and It can also help you get quality deep sleep.

Studies reveal that individuals who workout 2.5 hours per week [10] are twice as likely to get a better night's sleep. Further, individuals who work out for 30 minutes of mild or moderate exercise may see a difference in sleep quality the same night.

Though exercising has benefits, avoid intense workouts before bedtime. Intense exercise increases your heart rate, interrupting your sleep and overall duration.

Bedtime routine

Bedtime Routine

Establishing a sleep routine sounds easy, but with all the errands and unexpected events that occur throughout the evening before bed, it can be challenging for some.

Developing a sleep routine can help you achieve the right amount of sleep each night. Nighttime routines are often described as activities that occur right before bedtime each night. Not sure if you have a routine? Take a moment to write down your activities leading up to sleep.

Over time, you'll decide if you need to create one, adjust the current routine, or explore activities that can help you relax, including reading, listening to music, taking a warm shower or bubble bath, meditating, or performing 10-minute Yoga Nidra sleep meditation. Adopting a routine can help your mind associate the above activities with bedtime.

Sleep Tip: It’s OK if you don’t execute the routine the exact way every night. Worrying about perfecting your routine every night can create unwanted anxiety before sleep.

Read More: Yoga Nidra For Sleep

Yoga Exercises

Yoga is an excellent way to focus your mind and body. It can also enhance sleep quality by practicing cyclic meditation. Cyclic meditation combines yoga with rest periods while lying on your back. Performing this type of yoga can help improve deep sleep.

Before going to bed, try this 3-minute bedtime yoga routine. It may relax your mind and body. Wake up feeling refreshed and ready to take on the day. Here are two yoga exercises that you can try throughout the day:

Yoga Study: Positive Impact of Cyclic Meditation on Sleep [11]

White, Pink, or Brown Noise

Sleeping with white, brown, or pink noise plays a role in falling asleep and staying asleep throughout the night. As an air purifier, white noise machine, or fan, white noise is commonly used to help drown out or block out the noises that can keep you from getting a good night's rest.

Pink noise contains calming nature sounds such as rainfall, leaves rustling in the wind, or waves crashing on the beach. These sounds help increase deep sleep.

Sleep Study: A study of patients having trouble sleeping revealed that white noise helped them fall asleep 38% more quickly. [12]

Find Your Deep Sleep Sweet Spot

Though sleep needs vary from person to person, they are 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 if you can’t fall asleep within 20 minutes, don't stay in bed. Give one of the following a try if you can't fall asleep:

Can't Sleep, Do The Following

  • Meditating

  • Listening to Calming, Instrumental Music

  • Journaling

  • Read a Magazine or Book

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.

If you've learned anything from this post, it should be this: getting more deep sleep is essential for your long-term health. Take every measure possible to ensure you're getting it consistently.

Key Takeaways

As you can see, we need deep sleep for plenty of reasons. Along with being important, there are a few examples that illustrate why it’s necessary to get as much deep sleep as attainable on a nightly basis:

  • Increases growth of cell regeneration
  • Helps obtain a stronger immune system
  • Renews energy
  • Develops, grow, and repair bones and tissues
  • Boosts memory and learning
  • Repairs muscle and tissue
  • Enhances metabolism, heart health, and hormonal balance


[1] National Institutes of Health. National Institute of Neurological Disorders and Stroke. (Reviewed 2022, Apr 4). Brain basics: Understanding sleep. View Resource

[2] Patel, A. K., Reddy, V., & Araujo, J. F. (2022). Physiology, Sleep Stages. In StatPearls. StatPearls Publishing. View Study

[3] Institute of Medicine (US), Committee on Sleep Medicine and Research; Colten H.R., Altevogt, B.M. (Eds.). (2006). Disorders and sleep deprivation: An unmet public health problem. 2, Sleep physiology. Washington (DC): National Academies Press. View Study

[4] Drago, V., Foster, P. S., Heilman, K. M., Aricò, D., Williamson, J., Montagna, P., & Ferri, R. (2011). Cyclic alternating pattern in sleep and its relationship to creativity. Sleep medicine, 12(4), 361–366. View Study

[5] Yordanova, J., Kolev, V., Wagner, U., & Verleger, R. (2010). Differential associations of early- and late-night sleep with functional brain states promoting insight to abstract task regularity. PloS one, 5(2), e9442. View Study

[6] Troynikov, O., Watson, C.G., & Nawaz, N. (2018). Sleep environments and sleep physiology: A review. Journal of Thermal Biology, 78, 192-203. View Study

[7]Leger, D., Debellemanier, E., Rabat, A. Bayon, V., Benchenane, K., & Chennaoui, M. (2018). Slow-wave sleep: From the cell to the clinic. Sleep Medicine Reviews, 41, 113-132. View Study

[8] Johnson, D.A., Jackson, C.L., Williams, N.J., & Alcantara, C. (2019). Are sleep patterns influenced by race/ethnicity-A marker of relative advantage or disadvantage? Evidence to date. Nature and Science of Sleep, 11, 79-95. View Study

[9] Drake C; Roehrs T; Shambroom J; Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med 2013;9(11):1195-1200.

[10] Kredlow, M. A., Capozzoli, M. C., Hearon, B. A., Calkins, A. W., & Otto, M. W. (2015). The effects of physical activity on sleep: a meta-analytic review. Journal of behavioral medicine, 38(3), 427–449. View Study

[11] Patra, S., & Telles, S. (2009). Positive impact of cyclic meditation on subsequent sleep. Medical science monitor: international medical journal of experimental and clinical research, 15(7), CR375–CR381.

[12] Messineo, L., Taranto-Montemurro, L., Sands, S. A., Oliveira Marques, M. D., Azabarzin, A., & Wellman, D. A. (2017). Broadband Sound Administration Improves Sleep Onset Latency in Healthy Subjects in a Model of Transient Insomnia. Frontiers in neurology, 8, 718. View Study