How much deep sleep do you actually need? Our experts give you the answers for better sleep quality.

Sleep is one of the most important factors for our health, recovery, and daily performance. Yet, so many of us wake up feeling anything but refreshed, left wondering the same thing: am I actually getting enough deep sleep?

At Recharge Health, we spend every day looking at how the body recovers naturally, using technology that supports the body's own internal processes. Our approach is rooted in research on light, circadian rhythms, and recovery.

This article has been quality-checked by our clinical experts, including Dr. Zulia Frost, our Head of Medical and co-founder here at Recharge Health. She’s spent years working at the forefront of light therapy and recovery.

In this article, you’ll get a straightforward and easy-to-follow guide on:

• what deep sleep actually is
• how much deep sleep you really need
• how you can improve your sleep quality
• which steps actually work in practice

What is deep sleep and why is it so important?

Your sleep is made up of several different stages:

• light sleep
• deep sleep
• REM sleep

Deep sleep is what we call stage 3 sleep. This is where your body does most of its heavy lifting when it comes to repair work.

During deep sleep, a few key things are happening:

• your muscles and tissues are physically recovering
• growth hormones are being released
• your immune system is getting a boost
• your brain is "cleaning" itself through the glymphatic system

According to Dr. Zulia Frost, deep sleep - specifically slow-wave sleep -is the phase where the body enters its most important period for biological recovery. During this stage, the glymphatic system becomes highly active, helping to clear out metabolic waste from the brain while cell repair and energy restoration go into overdrive.

For a healthy adult, this phase should make up about 15–25% of your total sleep, though it naturally decreases as we get older. That’s why it becomes more and more important to protect this sleep stage for long-term brain and body health.

In short: without enough deep sleep, your body just can’t keep up with its necessary maintenance.

This is also why you can sleep for plenty of hours but still feel exhausted if the quality of that sleep is low.

How many hours of deep sleep do we actually need?

• A healthy adult should get between 1.5 and 2 hours of deep sleep every night, which works out to about 15–25% of your total sleep time.

For most adults, deep sleep makes up roughly:

• 15 to 25 percent of total sleep time

If you sleep for 8 hours, that typically means:

• about 1 to 2 hours of deep sleep

Deep sleep mostly happens during the first half of the night. That’s why it’s extra important to:

• stick to a consistent bedtime
• avoid cutting your night too short

What’s the magic number for total sleep hours?

Most adults need:

• 7 to 9 hours of sleep per night

This varies from person to person, but for most of us, getting too little sleep over time will lead to poor recovery and lower energy levels.

How much sleep do women need compared to men?

Women often have a slightly higher sleep requirement than men.

Possible reasons for this include:

• hormonal fluctuations throughout the menstrual cycle
• pregnancy
• a higher occurrence of sleep disturbances

The difference isn't huge, but many women will find they need:

• a bit more total sleep
• a more consistent circadian rhythm

How to get a good night's sleep when you're pregnant

Pregnancy has a big impact on sleep. Common challenges include general discomfort, waking up frequently, and hormonal shifts.

Things that often help:

• using pillows to support your bump and back
• sleeping on your side
• avoiding heavy meals late in the evening
• keeping the bedroom cool and dark

What should you do when you’re tossing and turning?

Most people go through periods where it’s hard to fall asleep. Here are some practical tips that actually tend to work:

• write down any thoughts or worries before bed
• avoid caffeine after 3:00 PM
• cut back on screen time in the evening
• get up at the same time every day
• avoid long naps during the day

Sleep problems are often about several things happening at once. It could be:

• stress
• irregular routines
• lighting conditions
• lifestyle

That’s why it’s so important to take a holistic approach to your sleep.

Want more deep sleep? Here are our expert tips

These are the steps that really make the biggest difference over time.

Consistency: Get up at the same time

Your body is run by an internal clock. When you get up at the same time every day, it becomes much easier to drift into a deep sleep when evening rolls around.

Temperature: Keep your bedroom between 18 and 19°C

A cool room makes it easier for your body to regulate its temperature and settle into a deeper sleep.

Diet and supplements: Is magnesium actually good for sleep?

Magnesium can help with:

• relaxing your muscles
• calming the nervous system

For some, this can make it easier to fall asleep and help improve overall sleep quality. That said, the effect varies quite a bit from person to person.

Light control: Avoid blue light from your phone before bed

Light is the single most important factor controlling your circadian rhythm.

To get better sleep:

• cut down on exposure to bright artificial light in the evening
• get some natural daylight early in the day

Modern life makes this a real challenge. Many of us get way too little daylight and far too much screen light late at night, which can really mess with our sleep quality.

Can red light therapy help you get more deep sleep?

Research suggests that red light therapy can help improve sleep quality and potentially support more deep sleep for some people. This is mainly because of how light affects the body’s internal clock (the circadian rhythm), the hormone melatonin, and the nervous system's ability to shift into a more recovery-focused state.

Light is one of the biggest external factors that tells us when to feel awake and when our bodies should start getting ready for bed. When you're exposed to the right kind of light at the right time, it hits those signals directly.

Red and near-infrared light are different from blue and bright artificial light because they don’t seem to mess with your melatonin production in the evening nearly as much.

At Recharge Health, we work with targeted red and near-infrared light technology through FlexBeam - a wearable solution that makes it easy to use light therapy right at home.

Research into red and near-infrared light technology has been going on for decades, and today it’s widely used for recovery and health optimization.

According to the clinical experts at Recharge Health, using light correctly can help support your body’s natural rhythms - and your deep sleep.

Many users find that they:

• fall asleep faster
• wake up feeling more refreshed
• experience better overall recovery

Results will vary from person to person, and this should be seen as a supplement to good sleep habits.

Better sleep with FlexBeam
I’ve been using FlexBeam regularly before bed, and it’s become a permanent part of my evening routine. The calming effect makes it much easier to wind down, and I’ve noticed a clear improvement in my HRV, which feels more balanced overall. The most impressive thing, though, is probably my sleep quality - I’m falling asleep faster and waking up feeling more refreshed.
Ann-Kristin

Conclusion: How to take control of your sleep quality

Deep sleep is essential for how you feel, perform, and recover.

In short:

• you should aim for 15% to 25% deep sleep
• total sleep needs are usually 7 to 9 hours
• routine, temperature, and light are the most important factors

If you’re looking to improve your sleep:

• start with the basics
• be consistent over time
• consider tools that can support your circadian rhythm

Small changes can lead to big improvements over time. Optimize your deep sleep with FlexBeam.

Discover why deep sleep is so important for your body and mind. Read more here.