How to Get More Deep Sleep: What Works and What Doesn't

If you want to know how to get more deep sleep, the most useful thing to understand is when it happens. Deep sleep is concentrated in the first few hours of the night, and it responds more to your habits than to any gadget or supplement. This guide covers what deep sleep is, what it does, how it changes with age, the habits that protect it, the things that cut it short, and what to make of tracker scores.

The short answer: deep sleep, also called slow-wave sleep or stage N3, is the quietest, hardest-to-wake stage of sleep, and most of it happens in the first half of the night. Adults spend roughly a fifth of their sleep in it. You can't force more of it, but you can protect it: keep a regular schedule, get enough total sleep, exercise, cut caffeine well before bed and go easy on alcohol. It naturally declines with age, so a lower figure in your 50s than in your 20s is normal.

What deep sleep is

Healthdirect describes deep sleep as the part of non-REM sleep where you are harder to wake, your body temperature drops, your muscles relax and your heart rate slows (source). On a brain recording it shows up as large, slow waves, which is why it's also called slow-wave sleep.

A 2024 review in Frontiers in Sleep puts slow-wave sleep at about 18% to 22% of total sleep time in adults and 20% to 30% in children, and notes it "commonly predominates during the first half of the night" (source). The Sleep Health Foundation says the same in plain terms: the first three hours of sleep have the deepest stages (source).

For how deep sleep sits alongside light sleep and dreaming sleep, see sleep cycles explained and what is REM sleep.

What deep sleep does

The Frontiers in Sleep review lists several jobs linked to slow-wave sleep:

• Growth and repair. Growth hormone is mostly released during slow-wave sleep.
• Memory. Patterns of brain activity in deep sleep are important for consolidating memories overnight.
• Brain clean-up. The brain's waste-clearing system is most active during slow-wave sleep.
• Immunity. Slow-wave sleep is linked with stronger immune memory.

This is why a night cut short at the start, or broken up early, can leave you feeling worse than one cut short at the end.

Deep sleep and age

Deep sleep declines through life. The same review reports that slow-wave activity falls by around 7% every five years between ages 5 and 15, then by about 2% every ten years in adulthood. The Sleep Health Foundation also notes that many older adults take longer to fall asleep and wake more during the night than when they were younger.

So comparing your deep sleep with a teenager's, or with your own from 20 years ago, will always look bad. The aim is to protect what you have, not to hit a younger person's number. See sleep after retirement for later-life sleep.

Habits that protect deep sleep

None of these is a hack. They work by giving your body the conditions it needs to do what it already does.

1. Get enough total sleep. Healthdirect says most adults need 7 to 9 hours. Your body tends to rebound with more slow-wave activity after sleep loss, but that's recovery, not a strategy.
2. Keep a regular schedule. The same bed and wake time, including weekends, helps your body clock time each stage. See fixed wake-up time.
3. Exercise. The Frontiers in Sleep review notes that exercise enhances slow-wave sleep in both young and older adults. Daytime activity is the easy win. See exercise and sleep.
4. Cut caffeine early. The Sleep Health Foundation says caffeine reduces time spent in slow-wave or deep sleep, can disrupt sleep even six hours before bed, and should be avoided for at least four hours before sleep (source). See caffeine and sleep.
5. Go easy on alcohol. Alcohol may make you drowsy, but the same page says it interferes with how you cycle through the normal stages of sleep.
6. Keep the room cool, dark and quiet. Better Health Channel suggests a bedroom temperature of around 17 to 19°C. See best bedroom temperature for sleep.
7. Protect the first few hours. Since deep sleep front-loads the night, a noisy start (a TV on, a partner's alarm, a pet settling) costs more than you'd think.

Deep sleep boosters: what the evidence says

Method	What's claimed	What the evidence says
Regular exercise	More deep sleep	Supported; enhances slow-wave sleep at all ages
Cutting caffeine	Less disruption	Supported; caffeine reduces deep sleep
Enough sleep, regular times	More stable stages	Supported; the foundation of everything else
Pink noise bursts timed to brain waves	Boosts slow waves	Lab studies with closed-loop EEG systems show effects; not the same as playing a noise track
Sleeping pills	More deep sleep	A 2019 review found drugs that raise slow-wave sleep showed limited benefit for memory or attention
Supplements	Deeper sleep	Little direct evidence; check with your GP or pharmacist first

The pink noise research is worth a word. A 2019 review in the Yale Journal of Biology and Medicine describes studies where 50-millisecond bursts of pink noise are played in time with the sleeper's own slow waves, using real-time EEG. This improved word-memory recall in most studies reviewed (source). A pink or brown noise playlist on your phone isn't doing that.

What about tracker scores?

Wearables usually estimate sleep stages from movement and heart rate rather than measuring brain waves, so their deep-sleep figures are a guess. If you feel rested, a low score isn't a problem. If you feel unrefreshed despite enough hours, that's worth taking seriously whatever the app says. See do sleep trackers work and still tired after 8 hours sleep.

Deep sleep is the hardest stage to wake from, and being woken from it is commonly linked with grogginess, known as sleep inertia. That's another reason to protect the first half of the night and keep naps short.

When to see your GP

See your GP if you snore loudly or stop breathing in your sleep, if you're very sleepy during the day despite enough time in bed, or if poor sleep has lasted more than a few weeks. This guide is general information, not medical advice.

Where the Sovune Nudge fits

We make the Sovune Nudge, a silent alarm wristband, so we're not neutral. It won't give you more deep sleep, but it can stop your early alarm from cutting into someone else's.

• Silent. No speaker, no sound and no light in the room, so a partner still in their first deep cycles isn't disturbed.
• Wakes you with vibration on your wrist, starting as a gentle tap and building through three intensity levels.
• Set on the band itself. No app and no phone by the bed.
• Under 20 grams, with a soft adjustable strap, so it doesn't get in the way of sleep.

It comes with a 30-day money-back guarantee.

Quick answers

How much deep sleep should I get? Roughly 18% to 22% of total sleep in adults, though it falls gradually with age. On a 7.5-hour night that's somewhere around an hour and a half.

When does deep sleep happen? Mostly in the first half of the night, especially the first three hours.

Does exercise increase deep sleep? Research reviews say exercise enhances slow-wave sleep in both younger and older adults.

Can you catch up on deep sleep? Your body tends to rebound with more slow-wave activity after sleep loss. See can you catch up on sleep.

For every type of silent alarm compared, see our complete guide to vibrating alarms in Australia.

See the Sovune Nudge →