How to Get More Deep Sleep, According to Sleep Science
And why you might not need to worry so much about it after all.
There’s a very good chance you’re giving your sleep more thought than ever before: 48% of US adults reported having used a sleep tracking device to monitor their sleep in a 2025 survey by the American Academy of Sleep Medicine (AASM). And many of these trackers don’t just count your minutes, but they also map out your sleep into a visually appealing graphic showing time spent in each stage — including the elusive but in-demand deep sleep, which is often promised as the most valuable and restorative of all the stages.
If you’re on a mission to maximize that dark blue sleep strip in your tracker app or just want to know what you can do to get more of the good stuff, keep reading: We’re breaking down everything you need to know about deep sleep, including what can boost or chip away at your deep sleep minutes, and what that actually means for your health.
TL;DR
You can influence your sleep, but you can’t really determine how much time you spend in each stage. Still, there are certain things you can do to improve your chances of getting sufficient deep sleep (aka slow-wave sleep). Focus on exercising regularly, avoiding excess or late caffeine, keeping your room cool, dark, and quiet. Giving yourself time to get enough sleep, on a consistent schedule, can also support sleep health overall.
Key Takeaways
- Deep sleep (aka slow-wave sleep) is the sleep stage where your body renews and repairs itself, and it's front-loaded in the first part of the night.
- To support healthy sleep and protect your deep sleep, exercise regularly, reduce caffeine intake later in the day, and maintain a cool, dark, quiet sleeping environment.
- Some disruptors of deep sleep include excess or late caffeine, smoking, a sleeping environment that’s too hot or noisy, sleep apnea, and certain medications.
- You probably don’t need to stress about how to get more deep sleep — getting enough sleep overall and following healthy sleep habits gives your body the opportunity to get the deep sleep it needs.
What Deep Sleep Is (and Why It’s Important)
The AASM divides sleep into four different stages: stage 1 (light sleep), stage 2 (a deeper state of light sleep), stage 3 (deep sleep or slow-wave sleep), and rapid eye movement (REM) sleep. You naturally cycle through different sleep stages about four to six times throughout the night; the cycle starts over every 80 to 100 minutes, and it’s possible to wake up briefly between cycles.
What’s so great about deep sleep? Well, stage 3 deep sleep is characterized by slow brainwave activity called delta waves. It’s the sleep stage where your body repairs and regrows tissues, builds bone and muscle, and strengthens your immune system, among many other things. It’s the hardest sleep stage to wake up from, and if you do wake up during this stage, it’s common to remain groggy from something called “sleep inertia.”
Adults spend approximately 10 to 25 percent of their total sleep time in deep sleep, but the proportion varies from person to person and decreases as you age. At the beginning of the night, your sleep cycles generally include longer periods in deep sleep and less time in REM sleep; as the night progresses, you spend less time in deep sleep and more time in REM.
How much deep sleep should you be getting? There’s no universal recommendation. Instead, the AASM and Sleep Research Society recommend adults get at least seven hours of total sleep per night on a regular basis to promote optimal health and well-being. And more deep sleep doesn’t necessarily mean better sleep overall. For example, alcohol can increase deep sleep early in the night while disrupting sleep later on and reducing REM sleep.
Worth noting: Most wearable trackers estimate sleep stages from signals like movement and heart rate. While they can offer some insight on your sleep habits and spot trends or changes, they’re not the same as a medical sleep study, which monitors brain waves to directly analyze your stages of sleep.
How to Get More Deep Sleep
There are certain behaviors that may help you get more deep sleep, but the most practical approach is to protect your sleep quality and give yourself enough time to sleep overall.
1. Follow a consistent sleep schedule and get enough ZZZs. The body tends to pack in more deep sleep in the first part of your sleep window, so sleeping longer doesn’t necessarily mean getting more deep sleep. Still, maintaining a consistent sleep schedule and leaving yourself enough time to rest supports overall sleep health and gives your body the opportunity to get the deep sleep it needs. To help you settle into that schedule, create a relaxing bedtime routine that allows you to wind down, avoiding bright light from screens and skipping heavy meals before bedtime.
2. Exercise regularly. Exercise may modestly increase the amount of deep sleep you get, as well as improve sleep quality, increase total sleep time, and decrease the amount of time it takes to fall asleep, according to a 2015 research review. A newer review in people with sleep disorders (including insomnia, obstructive sleep apnea, restless legs syndrome, and poor sleep quality) also found that exercise increased slow-wave sleep and reduced time spent awake after falling asleep.
3. Watch your caffeine intake and timing. A 2023 systematic review and meta-analysis found that, on average, caffeine consumption was linked to 11 fewer minutes of deep sleep and 45 fewer minutes of sleep overall. The research suggests that larger doses may have a greater impact, and that timing matters, at least with regard to total sleep time: the closer to bedtime that higher doses of caffeine were consumed, the greater reduction in total sleep time. There’s no single caffeine limit or cutoff time that works for everyone. If you’re having trouble sleeping, try limiting your caffeine or moving it earlier in the day to see if it helps.
4. Address symptoms of sleep apnea, if needed. Sleep apnea, a condition where breathing stops and starts several times during sleep, can interrupt sleep cycles and interfere with your ability to get deep sleep. Symptoms include loud snoring, episodes where your breathing stops during sleep (which other people might notice), gasping for air during sleep, waking up to a dry mouth, morning headaches, and trouble staying asleep. Talk to your doctor if you have any symptoms of sleep apnea.
5. Limit environmental disruptions. Optimizing your sleep environment may help you get more deep sleep. Research shows that noise may reduce slow-wave sleep and increase sleep fragmentation (when sleep is repeatedly interrupted), and that exposure to too much heat may decrease slow-wave sleep and REM sleep, and increase wakefulness. Some studies also show that exposure to light during sleep — for example, sleeping with a bedside light on — may also reduce slow-wave sleep. To improve your chances of sleeping well and maximizing deep sleep, keep your bedroom dark, comfortably cool enough to prevent overheating, and do what you can to limit noise.
What Hurts Deep Sleep
There are several factors that may interfere with your ability to sleep well, including how much deep sleep you’re able to get. Those could include:
- Excess or late caffeine consumption
- A sleeping environment that’s too hot or noisy
- Smoking and alcohol-use disorder
- Sleep disorders like sleep apnea
- Some medications, such as benzodiazepines
- Certain health conditions, such as depression
If you regularly have trouble getting enough sleep, wake up and don’t feel rested, feel overly tired or sleepy throughout the day, or experience any specific symptoms of sleep apnea, talk to your doctor. Trouble sleeping doesn’t always improve with lifestyle changes alone.
Frequently Asked Questions
To support deep sleep naturally, exercise regularly, limit excess or late-in-the-day caffeine, and create a cool, dark, quiet sleeping environment. It’s also helpful to maintain a consistent sleep schedule and give yourself plenty of time to get enough shut-eye (ideally at least seven hours a night) to support sleep health overall.
There’s no set amount of deep sleep that’s recommended for most people. Adults tend to spend approximately 10 to 25 percent of their sleep period in deep sleep, though that amount varies from person to person and decreases as you age.
A lot of things can interfere with or reduce your deep sleep, from medical considerations (including sleep disorders like sleep apnea, other medical conditions, and medications) to behavioral factors (including smoking, alcohol use disorder, and excess or late caffeine intake) and everyday sleep disruptions (such as a too-hot bedroom, light exposure, or noise).
Magnesium is gaining a reputation as a sleep-supporting supplement, but we don’t yet have enough evidence proving its benefit. Some small studies suggest magnesium might affect deep sleep, but there isn’t enough consistent evidence to recommend it specifically for increasing slow-wave sleep.
Deep sleep (slow-wave sleep) is when your body does most of its physical repair, and it’s the hardest stage to wake from. REM sleep, which comes later in each cycle, is when most vivid dreaming happens and is thought to support memory and mood. You move through both several times a night.
Bottom Line on Getting More Deep Sleep
In general, you don’t need to stress about doing extra to get more deep sleep. Other healthy lifestyle behaviors and sleep hygiene practices like exercising regularly, limiting caffeine late in the day, and maintaining a cool, dark, quiet bedroom can support healthy sleep, including deep sleep. And if you’re using a sleep tracker to keep an eye on how much deep sleep you’re getting, take those reports with a grain of salt: They can provide an estimate of your deep sleep, but aren’t an exact measurement and can’t prove a deficiency. If you’re having trouble falling or staying asleep or are experiencing symptoms of sleep apnea, talking to a doctor is the proper next step.
