How to Get More Deep Sleep: What It Is, How Much You Need and Tips That Work

01Basics

What deep sleep is

Sleep cycles through light sleep (N1 and N2), deep sleep (N3) and REM sleep roughly every 90 minutes. During deep sleep, brain waves are slow and large, breathing and heart rate slow down, and it is hard to wake up. Growth hormone is released, muscles and tissues recover, the immune system is supported and the brain clears waste products and strengthens memories. REM sleep, in which most vivid dreaming happens, is concentrated in the second half of the night.

02How much

How much deep sleep do you need?

• Adults typically spend about 13 to 23 percent of total sleep in deep sleep, roughly one to two hours in a seven to eight hour night.
• Children and teenagers have much more deep sleep.
• Deep sleep declines with age, and older adults may have little, which is normal.
• Most deep sleep happens in the first three to four hours of the night.

There is no exact target number. Feeling refreshed, alert during the day and able to function well is a better guide than a tracker score.

03Tips

Habits that increase deep sleep

• Keep a regular schedule: the same wake-up time every day, including weekends.
• Get enough total sleep: seven to nine hours for most adults; deep sleep cannot happen if sleep is cut short.
• Morning daylight: 20 to 30 minutes outside early in the day strengthens the body clock.
• Exercise regularly: aerobic exercise and strength training increase deep sleep; finish intense workouts a few hours before bed.
• Avoid long or late naps, which reduce sleep pressure.
• Limit caffeine after about 2 pm; it reduces deep sleep even if you fall asleep easily.
• Avoid alcohol in the evening: it makes you drowsy but fragments sleep later in the night.
• Keep the bedroom cool (around 16 to 19 °C), dark and quiet.
• A warm shower or bath one to two hours before bed helps the body cool down afterwards, which promotes sleep onset.
• Avoid heavy meals within two to three hours of bed.
• Wind down: a relaxing routine and less screen use in the last hour.
• Manage stress: relaxation, breathing exercises or journalling reduce night-time arousal.

04Reduce

What reduces deep sleep

• Alcohol, caffeine, nicotine and some medicines.
• Irregular sleep times and shift work.
• Chronic stress and anxiety.
• Sleep apnoea, which repeatedly interrupts deeper stages.
• Chronic pain, restless legs and frequent night-time urination.
• Ageing.

05Supplements

Do supplements help?

Evidence that supplements increase deep sleep is limited. Melatonin mainly helps with timing of sleep, for example jet lag, rather than deep sleep. Magnesium may help people with low intake; see magnesium threonate vs glycinate. Sleeping tablets can make you sleep but often reduce deep sleep. See over-the-counter sleep aids and valerian root.

06Trackers

Are sleep trackers accurate?

Wearables and phone apps estimate sleep stages from movement and heart rate. They are reasonably good at telling sleep from wake but much less accurate at measuring deep sleep. Worrying about tracker scores can itself make sleep worse, a pattern sometimes called orthosomnia. Use trackers to spot trends, not to judge each night.

07Insomnia

If you cannot sleep well

If you struggle to fall or stay asleep at least three nights a week for three months, you may have insomnia. Cognitive behavioural therapy for insomnia (CBT-I) is the most effective long-term treatment and improves sleep depth and continuity. See insomnia, can’t sleep: what to do and fragmented sleep.

09Shift work

Shift workers

Shift workers can protect deep sleep with blackout curtains, earplugs, a consistent sleep block after shifts and limiting caffeine in the second half of the shift.

10Summary

Key points to remember

• Deep sleep is concentrated early in the night and decreases with age.
• Consistent timing, enough total sleep and exercise are the strongest levers.
• Alcohol and late caffeine reduce deep sleep.
• Feeling rested matters more than tracker numbers.