How to Get More Deep Sleep

While every sleep stage occurs during sleep, deep sleep plays a critical role in our overall health and wellness. During deep sleep, our bodies carry out a host of biological functions that directly contribute to how we feel and how we perform.

Our brains process and sort information from the day and form memories, and our bodies go into active repair mode, releasing hormones for growth and repair and crucial proteins needed to fight illness and disease effectively.

What Are the Stages of Sleep?

According to the National Library of Medicine, sleep comes to us in four stages.Verified Source National Library of Medicine (NIH)World’s largest medical library, making biomedical data and information more accessible.View source Broken down into two categories: non-REM (NREM) sleep and REM sleep. The four sleep stages are N1, N2, N3, and REM. Each one is different, and each one plays an important role in our overall sleep quality. 

Non-REM sleep (or non rapid eye movement) includes the N1, N2, and N3 stages of sleep. Non-REM can account for 75% of total sleep time in adults and 50% ofVerified Source National Library of Medicine (NIH)World’s largest medical library, making biomedical data and information more accessible.View source total sleep time in infants.

“It really depends on sleep duration,” says Dr. Renske Lok. “If you have a group of adults that sleep too short, NREM sleep will take up the majority of sleep. However, in adults that sleep sufficient, there will be lots of REM sleep towards the end of the night.”

The N3 stage is the deepest stage of sleep and usually the hardest to wake up from.

REM sleep is the last stage and the one where we have our most vivid dreams. Most people will slip into this stage anywhere from one hour to 1.5 hours after falling asleep. The first REM stage of the night is typically the shortest. As the night goes in, the REM stages get longer and the deep sleep decreases.

“The reason why there’s more REM sleep at the end of the night is that the need for NREM sleep decreases,” notes Dr. Lok on the cycling nature of sleep stages during each sleep cycle.

Before you fall asleep, your body’s core temperature drops, usually coinciding with melatonin production.

NREM Stage N1

This first stage of non-REM sleep is typically a transition from wakefulness to sleep. This is essentially where you “drift off.” Stage 1 or N1 is the lightest stage of sleep and usually only lasts for a few minutes. Stage N1 accounts for about 5% of total sleep time. 

During the N1 stage:

• Larger muscles begin to relax
• Body temperature continues to decrease
• Heartrate and breathing slow down
• Hypnic jerks (or the feeling of falling) are a common occurrence

NREM Stage N2

After N1, sleepers move into Stage 2 or N2. Out of the three stages of sleep, we spend most of our time in N2. This stage typically lasts up to 25 minutes and accounts for about 45% of our total sleep time. N2 is characterized by light sleep, and most people can be awakened easily. A 2022 studyVerified Source ScienceDirectOne of the largest hubs for research studies and has published over 12 million different trusted resources.View source also suggests that N2 sleep is important for self-reported sleep quality.

During the N2 stage:

• Heartrate and breathing slow down further
• Eye movements cease
• Body temperature continues to decrease
• The sleeper disengages from their environment

NREM Stage N3

Stage 3 or N3 is also known as slow-wave sleep (SWS). N3 is also known as delta sleep because delta brain waves slow down. N3, or slow-wave sleep, is the deepest sleep stage and the one that directly contributes to quality sleep and how refreshed you feel when you wake.

Our bodies perform myriad biological housekeeping functions during N3 or deep sleep. This is also the stage when sleep disorders like sleepwalking, night terrors, and bedwetting occur. Our time spent in deep sleep only accounts for about 25% of our total sleep time. 

During the N3 or deep sleep stage:

• Heartrate and breathing are at their lowest levels
• Blood pressure drops 
• Muscles are fully relaxed
• Growth hormones are released
• Tissue repair occurs 
• Immune system strengthens as cytokines are releasedVerified Source National Library of Medicine (NIH)World’s largest medical library, making biomedical data and information more accessible.View source to reduce inflammation and fight infection
• Glymphatic clearanceVerified Source National Library of Medicine (NIH)World’s largest medical library, making biomedical data and information more accessible.View sourceoccurs, the main source of “waste clearance”

REM Stage 

The rapid eye movement, or REM stage, is the last sleep stage of a typical sleep cycle. Most people will enter REM somewhere around the 90-minute mark after they fall asleep.

However, a recent 2024 study concluded that your duration of sleep cycles varies with age, sex and sleep homeostasis.

In the initial sleep cycles of the night, REM sleep may only last for about 10 minutes. As the night progresses, the REM cycles grow longer, and it’s not uncommon for the last REM cycle of the night to last for up to an hour. REM is the stage most commonly associated with dreaming, and contrary to what many people believe, it’s not the most restful stage of sleep. This stage accounts for 25% of our total sleep time. 

During the REM sleep stage:

• Heart rate and breathing speed up and often become irregular 
• Eye movements speed up
• Muscles become paralyzed (muscle atonia)
• Brain activity increases

Sleepers typically cycle through all these stages of sleep every 90 minutes, multiple times per night.

How Much Deep Sleep Do You Need?

“The billion-dollar question that we don’t have a question to,” notes Dr. Renske Lok. “All we have is statistics on what people do, but the interindividual differences are large.”

Yes, there are no hard and fast rules for how much deep sleep we need. While most people spend about 25% of their total sleep time in deep sleep, sleep architecture (how we move through sleep cycles and how long we spend in each) changes over time.

As we age, sleep quality and quantity decrease, as does the total time spent in deep sleepVerified Source National Library of Medicine (NIH)World’s largest medical library, making biomedical data and information more accessible.View source or slow wave sleep time. 

A 2017 reviewVerified Source MedscapeOne of the largest hubs for research studies and has published over 12 million different trusted resources.View source of available data and expert advice noted that “There is consensus among experts regarding some indicators of sleep quality among otherwise healthy individuals. Education and public health initiatives regarding good sleep quality will require sustained and collaborative efforts from multiple stakeholders. Future research should explore how sleep architecture and naps relate to sleep quality.”

“It is far from complete and there’s lots that still needs to be detected, but it is a solid start,” Dr. Lok says of this paper.

“However, this might also be a consequence of how we measure sleep. We use polysomnography, attaching electrodes to someone’s skull and picking up on cortical electrophysiology, but as we age, it’s possible that the brain shrinks and therefore moves away further from the corex. When we’re older, the PSG might simply pick up on less signal as opposed to the sleep need really changing.”

How to Get More Sleep

Avoid Caffeine 

Caffeine is a stimulant, and while it may give you a boost to get you over the 3 p.m. slump, it can overstay its welcome by disrupting your sleep hours later. 

And the blow caffeine can deliver to your sleep has been well-documented. One study showed that not only does the consumption of caffeine reduce the amount of time spent in sleep stages 1 and 2, but it also delays sleep onset by as much as 40 minutes or more.,depending on when you ingest caffeine and how your body metabolizes it. Moreover, the same study showed that caffeine unequivocally reduces the duration of deep sleep.

And don’t forget, caffeine isn’t limited to coffee. Sodas, sports drinks, chocolate, and some pain relievers may also get in the way of getting enough sleep.

Skip the Nap 

Napping during the day might sound like a good idea for those who want to make up for lost sleep, but this, too, can come with a heavy price tag — less deep sleep.

The sleep science works something like this: If you take a nap during the day, you’re essentially releasing the pressure on your sleep drive (sleepiness or desire to sleep), and when bedtime comes, that need has already been met, and it’s that much harder to get into a deep sleep phase. 

For those feeling sleepy during the day, the better bet is to let your sleep drive build and get a good night’s sleep when bedtime rolls around.

If you absolutely must nap during the day, limit it to 20-30 minutes, and do it early enough that it won’t interfere with your ability to sleep come nighttime. 

Limit Light Exposure 

You’ve probably noticed that as the sun goes down each day and evening rolls in, you start feeling sleepy. The circadian clock produces melatonin, but only in the absence of light or under low-intensity light conditions.

The hormone melatonin is part of regulating the body’s sleep-wake cycle and helps makes you feel sleepy at night and reduce your core body temperature, two key signals to tell your body that it is time to go to sleep. The rise of melatonin at night makes us feel sleepy, and the decrease of melatonin as the sun begins to rise helps us wake up.

If we’re exposed to light at night, everything goes off the rails. Light suppresses the release of melatonin. 

One study showed thatVerified Source National Library of Medicine (NIH)World’s largest medical library, making biomedical data and information more accessible.View source late light exposure can contribute to more nighttime wakings and less deep sleep. All things considered, you may want to dim the lights around your home and bedroom in the evening. 

Put Your Devices Away Before Bedtime

You may want to rethink the time you spend on your devices before bed – for two reasons.   

First, we already know that bright light affects sleep (see above). While bright lights can affect your ability to fall asleep and your overall sleep quality, research shows that blue light (the kind of light emitted from (phones, tablets, computers, TVs in the bedroom, and even energy-efficient lighting) can deliver an even bigger blow to your sleep. 

Harvard researchers found that blue lightVerified Source Harvard HealthBlog run by Harvard Medical School offering in-depth guides to better health and articles on medical breakthroughs.View source has a profoundly suppressive effect on melatonin production and that it can shift circadian rhythms by as much as 3 hours. 

And not to be the bearers of bad news, but if you think e-readers are a good compromise, guess again. Another studyVerified Source National Library of Medicine (NIH)World’s largest medical library, making biomedical data and information more accessible.View source found that reading on an e-reader for four hours before bed reduced melatonin production and evening sleepiness, delayed sleep onset, and impaired alertness upon waking. 

The other reason to skip your nighty scroll? The stress from catching up on the news and social media is enough to keep anyone up at night. 

“In general, scientists agree that this it the main reason for effects of these devices on sleep and not the light,” says Dr. Lok. “The light intensities coming from these devices is relatively low, and there has yet to be a good study that disentengles light effects from the mentally stimulating effects. The current thinking is that it is predominantly the stress and stimulation and not the light.”

Maintain a Consistent Sleep Schedule

Irregular sleep schedules can disrupt your circadian rhythm and sleep quality, leaving you feeling tired and sluggish instead of refreshed and restored. Good sleep hygiene, like maintaining a consistent sleep-wake schedule, however, is key to good sleep health.

So much so that The National Sleep Foundation (NSF) just issued a new guideline emphasizing the benefit of consistent sleep-wake schedules.

And there’s no mystery here: maintaining a consistent sleep schedule simply means going to bed and waking up at the same time every day, even on the weekends, even on holidays. 

Create a Comfortable Sleep Environment

In order to get enough deep sleep, you’re going to have to set the stage. For starters, this means ensuring your bedroom is cool, dark, and quiet. If need be, consider using blackout curtains, earplugs, eye masks, or white noise machines. 

Optimizing your sleep environment may also mean reevaluating your mattress, pillows, and bedding. We spend one-third of our lives in bed, so if there’s ever a place for an investment, this might be it. Overall, you want to make sure you have the right mattress and pillows for your preferred sleeping positions and bedding that matches your sleep temperature. 

Create a Relaxing Bedtime Routine

Bedtime routines are most often associated with kids, but they can be pretty helpful for adults, too. A bedtime routine for adults is nothing more than creating a relaxing routine that helps you wind down in the hours leading up to bedtime. 

Bedtime routines can include 

• Dimming the lights
• Putting away tech
• Reading a book (a similar low-key activity) 
• A warm bath
• Listening to music 
• Journaling 

Stick to a Healthy Diet

If you’ve ever eaten a heavy meal before bed, then you know that eating too close to bedtime can hamper your sleep. One study even demonstrated that eating a meal within 3 hours of bedtime increases your chancesVerified Source National Library of Medicine (NIH)World’s largest medical library, making biomedical data and information more accessible.View source of waking up during the night by around 40%.

That said, a good rule of thumb is to avoid heavy meals, spicy foods, and sugary treats before bed — none of the above make good bedfellows. Moreover, you may want to consider reducing your fluid intake in the hours leading up to your bedtime, as frequent bathroom trips will most certainly pave the way for insufficient sleep.

Exercise 

For those looking for more deep sleep, the answer may lie in daily exercise. And no one’s saying that you need a gym membership or to deadlift 200 lb from one day to the next. Boosting your physical activity is as easy as reserving 30 minutes out of your day to do whatever exercise you like the most. Walk the dog, follow an exercise routine on YouTube, or play with your kids in the backyard — the choice is yours. 

The one caveat here is don’t do any strenuous exercise too close to bedtime. The adrenaline boost and rising cortisol levels, as well as the increase in body temperature that these cause, can lead to poor sleep.  

What Causes a Lack of Deep Sleep?

Research shows that we spend about 25% of our total sleep time in deep sleep. However, stress,Verified Source Oxford AcademicResearch journal published by Oxford University.View source a change in sleep patterns and sleep cycle duration due to aging,Verified Source Oxford AcademicResearch journal published by Oxford University.View source chronic pain, and sleep disorders like sleep apnea can reduce deep sleep. 

FAQs

How do I know if I’m getting enough deep sleep?

NREM sleep does the heavy lifting to make us feel restored and refreshed. If you consistently wake up feeling tired and sluggish, that could be a good indication that you’re not getting enough sleep.

How can I get more sleep?

If you find that you’re having trouble sleeping or looking for ways to get more sleep, lifestyle changes and sleep hygiene adjustments may be helpful. Consider picking up a daily exercise routine, limiting caffeine, and making your room as cool, dark, and quiet as possible. 

Does melatonin help you get more deep sleep?

Melatonin supplements are commonly used as a sleep aid. And while most people take it because they think it will induce sleep, that’s not quite the case. Melatonin promotes sleep and regulates your sleep cycle, but sleep medicine reviews show that melatonin may not increase sleep or work for everyone. 

What happens if you don’t get enough deep sleep?

A lack of deep sleep is a type of sleep deprivation. Over the short term, a lack of any type of sleep may cause excessive daytime sleepiness, fatigue, impaired cognitive function, and irritability. Over the long term, a lack of deep sleep may lead to more serious health issues like high blood pressure and heart disease.

“Deep sleep occurs first, so when you’re sleep deprived it’s mostly REM sleep that is depleted,” notes Dr. Lok.

Conclusion 

Each night, our bodies cycle through four stages of sleep. The third stage, or N3, is the deep sleep stage, also known as slow wave sleep or delta sleep.

Biological processes happen during all stages of sleep, directly contributing to our overall health and wellness. During deep sleep, memories are formed and consolidated, growth hormone is released, and our immune system gets a boost when cytokines are released.

In addition to deeper sleep, this is also the stage when sleep disorders occur. Deep sleep is also responsible for restful sleep.

A series of lifestyle changes and modifications to your sleep habits can help you get more sleep, avoiding the effects of sleep deprivation.

To help you get adequate sleep and keep your circadian rhythms on track, consider lifestyle changes like avoiding caffeine, modifying your sleep hygiene by optimizing your sleep environment, maintaining a consistent sleep schedule, and creating a relaxing bedtime routine.