Deep sleep is the most restorative stage of sleep. During the night, we go through several sleep cycles, but maximizing deep sleep helps your body recover best. 

If you’ve ever woken up feeling really groggy or disoriented, that’s what it feels like to wake up from a deep sleep. 

So, how much deep sleep do you need? This article explains the science behind deep sleep and how to maximize it for better rest.

What is Deep Sleep?

Deep sleep, or Stage 3 non-REM sleep, also called slow-wave sleep, is where your body and mind recover and restore themselves.

During deep sleep, your brain waves slow, and your body focuses entirely on physical recovery. 

What Happens During Deep Sleep

The physiological changes that take place during the deep sleep stages are:

  • Brain waves produce slow, high-amplitude waves called delta waves. This is where your brain activity is at its lowest.

  • Physical repair: Your pituitary gland releases HGH (human growth hormone), which stimulates tissue growth and muscle repair.

  • Immune system: This is the stage when your immune system becomes stronger, helping your body fight off illnesses.

  • Detoxification: Your brain’s waste clearance system becomes highly active, clearing metabolic waste, especially beta-amyloid, which has been linked to Alzheimer’s disease.

  • Heart and lungs restore themselves. Your heart rate and breathing reach their slowest rates, and your blood pressure drops.

How Much Deep Sleep is Normal?

How much deep sleep do you need? Generally, deep sleep makes up about 13-23% of your total sleep time. During a typical 8-hour sleep, that amounts to roughly 60 to 110 minutes.

Deep sleep stages typically occur during the first half of the night. As the night goes on, the balance shifts from deep sleep to REM sleep. This is why going to bed late compromises deep vs. REM sleep: you miss a good portion of it.

Why Deep Sleep Matters

If you don’t get enough deep sleep, even after sleeping for 8 hours, you wake up feeling physically exhausted and mentally fuzzy.

This is why deep sleep is essential for restoring your body’s functions, including physical recovery, energy renewal, memory consolidation, and metabolic health.

Physical recovery: Repairs muscles and tissues after daily wear and tear.

Energy renewal: ATP, or adenosine triphosphate, is your body’s energy source, and this is when it gets replenished.

Memory consolidation: Supports declarative memory, which includes facts, dates, and names.

Metabolic health: Helps regulate glucose metabolism and insulin sensitivity.

Deep vs. REM Sleep

There are four stages of sleep. Stage 1 is the lighted sleep and happens right when a person falls asleep. 

In stage 2, the body relaxes even more deeply, body temperature decreases, muscles loosen, and the heart rate and breathing slow down.

In stage 3, this is where we enter deep sleep, the most restorative and deepest part of the sleep cycle.

Stage 4 is REM sleep. Most of our dreaming occurs in this stage. Your brain activity increases, and the body becomes temporarily paralyzed.

A simple way to see the difference between these two stages is that deep sleep is the physical maintenance stage, while REM sleep is like a software update. Both are essential, but they occur at different times and serve very different purposes.

Deep sleep: Bodily restoration occurs. Slow brain waves. Your body is still but capable of movement, and dreams rarely occur, just feelings and images.

During REM sleep, cognitive processing and emotions take place. You experience very high brain waves, and your body is paralyzed except for your eyes and breathing. Dreaming is vivid, story-like, and intense.

Factors That Affect Deep Sleep

How you prepare your body before sleep has the most impact on deep sleep. 

Factors that affect deep sleep include chemicals like caffeine, alcohol, and nicotine. All of these make it more difficult for the brain to transition into deep and REM sleep.

Age is another major factor. As we age, the amount of deep sleep naturally decreases. By age 70, many people get significantly less deep sleep than they did in their 20s.

On the other hand, if you are sleep deprived, your body will respond by prioritizing deep sleep the next time you go to bed. 

This is known as rebound sleep. Your brain skips the lighter sleep stages and moves directly into deep sleep as quickly as possible.

Exercise is one of the best ways to increase deep sleep, including activities like running, swimming, and weight lifting. 

HIIT, on the other hand, if done too close to bedtime, will raise your core temperature too high, which inhibits deep sleep.

High body temperature, caused by a hot room, can prevent deep sleep. Noise and light also interfere with sleep.

And finally, sleep apnea and restless leg syndrome prevent you from reaching deep sleep because of the disruptions caused by these sleep disorders.

Science-Backed Ways to Improve Deep Sleep

How much deep sleep do you need? Work towards 60-110 minutes of sleep out of 8 hours.  

Here are some ways to improve deep sleep by focusing on two areas: increasing the biological need for sleep and lowering your core temperature.

  1. Cool your room: The ideal sleeping temperature is between 60 and 67 degrees F. 

  2. Take a warm bath or shower 1-2 hours before bed. This actually cools your core, which signals your brain it’s time to sleep.

  3. Studies have shown a link between high fiber intake and deep sleep.

  4. Cut sugar. A high sugar diet and saturated fats are linked to lighter, more disturbed sleep.

  5. Pink noise is scientifically proven to promote deep sleep. It mimics steady rain or rustling leaves because it works in lower frequencies. Research shows that pink noise can synchronize with your brain’s slow waves, boosting them and lengthening deep sleep.

  6. Supplements like magnesium help regulate your neurotransmitters, quiet your nervous system, and improve sleep efficiency. 

  7. Avoid alcohol.

  8. Get morning sunlight to set your circadian rhythm. 

  9. Increase vigorous exercise for enhanced deep sleep.

How Yana Can Help You Optimize Deep Sleep

The right pillow can greatly affect your ability to fall into a deep sleep. The Yana full body pillow is an ideal choice for comfort. It helps achieve proper alignment of the spine from the head and neck down through the shoulders, hips, and knees. 

When your body feels comfortable and properly aligned, falling asleep becomes easier when all your joints are cushioned, and there are no pain points.

The side sleeper pillow also improves your sleep by reducing pressure on your neck and back. Pair it with our aromatherapy-weighted eye mask to block out disruptive light and help you fall into a deep sleep. 

Yana Sleep products were designed to promote deep sleep. Free from harmful chemicals, with breathable, easy-to-wash covers, all crafted to provide comfort and full-body support. 

Shop Yana Sleep products today!