Power nap length: how long to nap, and how to wake up fresh instead of groggy
The ideal power nap length is 10 to 20 minutes of sleep. In a sleep-lab study, a 10 minute nap lifted alertness straight away, with no grogginess after.
- Length: a power nap of 10 to 20 minutes of sleep gives the most benefit with the least grogginess.
- Evidence: in a 2006 study of 24 adults, a 10 minute nap improved alertness and performance at once, with some benefits lasting 155 minutes.
- Grogginess: a 30 minute nap caused a spell of poorer alertness straight after waking, called sleep inertia, before the benefits arrived.
- Timing: early afternoon suits most people, because that is when the body’s natural dip in alertness falls.
- Alarm: set it for your nap length plus the time you usually take to fall asleep, often 5 to 10 minutes.
How long should a power nap be?
The best power nap length is 10 to 20 minutes of sleep. That is long enough to feel the benefit, and short enough that you wake before sinking into deep sleep. Ten minutes is the safest choice if you need to get straight back to work.
Note the words “of sleep”. Most people take a few minutes to drop off, so the time on your alarm should be a little longer than the nap itself:
- Fall asleep fast: set the alarm for about 15 minutes.
- Take a while to settle: set it for 20 to 25 minutes.
- Never go past about 30 minutes if you want to wake up sharp.
What does the research say about nap length?
The clearest answer comes from a 2006 study in the journal Sleep. Researchers at Flinders University limited 24 healthy young adults to about 5 hours of sleep, then tested naps of exactly 5, 10, 20 and 30 minutes of sleep at 3 pm, against no nap at all.
| Nap (minutes of sleep) | What happened afterwards |
|---|---|
| 5 | Few benefits compared with no nap |
| 10 | Less sleepiness and fatigue, better performance straight away; some benefits lasted up to 155 minutes |
| 20 | Benefits appeared about 35 minutes after waking and lasted up to 125 minutes |
| 30 | Worse alertness right after waking, then benefits lasting up to 155 minutes |
The authors concluded that 10 minutes was the most effective nap length they tested. It is one study with 24 people, all young and short on sleep, so treat the exact numbers as a guide rather than a rule.
It also answers a common question: is a 20 minute nap better than 10? Not straight away. The 20 minute nap helped too, but only from about 35 minutes after waking, while the 10 minute nap helped at once. So choose by what comes next. With a meeting in 15 minutes, keep it short. With an hour to spare, 20 minutes is fine.
Why do you feel worse after a nap?
The heavy, foggy feeling after a nap is called sleep inertia: your brain is still partly asleep while you are already awake. It is stronger when you wake from deep sleep, which becomes more likely the longer you nap. In the 2006 study, the 30 minute nap left people less alert at first, before the benefits arrived.
Sleep inertia usually fades within the hour. You can help it along:
- Get up as soon as the alarm goes, rather than snoozing.
- Find bright light, ideally daylight.
- Splash cold water on your face and drink a glass of water.
- Move for a few minutes before you sit back down.
A longer nap of around 90 minutes, roughly one full sleep cycle, can also avoid grogginess, because you tend to wake from lighter sleep. But it is no longer a power nap, and it can make it harder to sleep that night.
When is the best time for a power nap?
Early afternoon is the best time for most people. Alertness naturally dips in the early afternoon, and a nap at that point works with your body rather than against it. The 2006 study napped at 3 pm, and the coffee nap study below at 12:40.
Avoid napping late in the day. A nap in the evening takes the edge off your sleep pressure, the build-up of tiredness that helps you fall asleep, and bedtime gets harder. If you often need a nap to get through the day, or fall asleep without meaning to, talk to your doctor.
Does a coffee nap work?
A coffee nap means drinking coffee just before a short nap, so the caffeine starts working as you wake. There is some evidence it helps. In a 2003 study in Clinical Neurophysiology, 10 young adults took 200 mg of caffeine, roughly two cups of coffee, right before a 20 minute nap. That combination beat a nap alone for afternoon sleepiness and performance, and the effect lasted the full hour they were tested. Bright light straight after the nap worked about as well for sleepiness, though not for performance.
It is a small study, so treat it as worth a try rather than proven. If you are pregnant or sensitive to caffeine, ask your doctor first. And never listen to binaural beats while driving.
How do you fall asleep fast and wake up fresh?
Keep it simple: dark, quiet, lying back, alarm set. Low, steady sound can help you stop listening to the room. A slow binaural beat for sleep or soft brown noise works for many people; our guide to the best frequency for sleep explains the bands.
In Shimmr, set the sleep timer so the sound fades out on its own instead of cutting off, and keep a normal alarm to wake you. When you are up, play the Flat → Bright Shift, which moves the beat from alpha waves up to beta over 10 minutes, while you get some light and a glass of water.
Common questions
How long should a power nap be?
Aim for 10 to 20 minutes of sleep. In a 2006 sleep-lab study, 10 minutes gave the quickest lift, and 30 minutes left people groggy at first.
Is a 20 minute nap better than 10?
Not straight away. In the same study, the 10 minute nap helped at once, while the 20 minute nap’s benefits only showed up about 35 minutes after waking.
Why do I feel worse after a nap?
That heavy, foggy feeling is sleep inertia. It is more likely after longer naps, when you wake from deeper sleep, and it usually fades within the hour.
What is the best time of day for a power nap?
Early afternoon, during the natural dip in alertness after lunch. Napping late in the day can make it harder to fall asleep at night.
Does a coffee nap work?
There is some evidence. In a small 2003 study of 10 adults, 200 mg of caffeine taken just before a 20 minute nap beat a nap alone against afternoon sleepiness.
This article is for general information and is not medical advice. Binaural beats are not a treatment for insomnia or any other condition.