Some people swear by an afternoon nap. Others feel groggy and guilty after one.
So is napping good for you? The research gives a two-part answer.
Short naps seem to help your brain. Long, frequent naps are linked to health problems, though they may be a warning sign rather than the cause.
- In lab studies, an afternoon nap improved thinking and alertness for up to about two hours afterwards.
- In a review of 21 studies, naps under an hour weren’t linked to higher death risk. Naps of an hour or more were.
- US health guidance suggests keeping naps to 20 minutes or less.
Is napping good for you?
A short nap is generally good for you, especially for alertness. Long or very frequent daytime napping may be a sign that something else is wrong.
The US National Heart, Lung, and Blood Institute says napping “may boost your alertness and performance”. It adds: “Adults should nap for no more than 20 minutes.”
It also advises that if you have trouble falling asleep at night, you should limit naps or take them earlier in the afternoon.
The US National Institute on Aging gives similar advice: “Avoid napping in the late afternoon or evening.”
The key is the length and the reason you’re napping.
What the research shows
The benefits: a sharper brain
A 2021 meta-analysis in the International Journal of Environmental Research and Public Health pooled 11 lab studies, with 381 participants.
After a nap, overall thinking performance improved compared with people who stayed awake. The biggest boost was in alertness.
The benefits mainly lasted up to 120 minutes after the nap. They didn’t depend on age or sex.
| Thinking skill | Effect of a nap |
|---|---|
| Overall thinking | Small improvement |
| Alertness | Clearest improvement |
| Executive function (planning, focus) | Small improvement |
| Memory | Not significant in this review |
A larger 2022 review in Sleep Medicine Reviews, covering 54 studies, found small to medium benefits across many tests. That included memory, vigilance and processing speed.
Why long naps can leave you groggy
Earlier research, summarised in the 2023 Sleep Health study, found benefits arrive right after a brief nap of five to 15 minutes. They can last one to three hours.
After a long nap of more than 30 minutes, performance can temporarily get worse before it improves. That groggy feeling is called sleep inertia.
The 2021 review also found mixed results during this groggy period, right after waking.
The risks: when naps get long
The main review of health risks is a 2024 meta-analysis in PLOS ONE. It pooled 21 cohort studies with 371,306 people.
Overall, people who napped had a higher risk of death than people who didn’t. But the length of the nap made a big difference.
| Nap length | Risk of death vs no naps | Risk of heart disease vs no naps |
|---|---|---|
| Under 1 hour | No difference | No difference |
| 1 hour or more | 22% higher | 37% higher |
The study had no outside funding, and the authors declared no competing interests.
Short naps sharpen alertness for a couple of hours. Naps of an hour or more are linked to higher risks, but that link may reflect existing health problems.
Why I read the risk numbers carefully
These are observational studies. They show a link, not proof that long naps cause harm.
People who are already unwell, or who sleep badly at night, may nap more. So long naps may be a symptom of a problem, not its cause.
The review’s own conclusion uses stronger language than its data can support. I’ve stuck to “linked to”.
Is there a sweet spot?
A 2020 dose-response meta-analysis of 20 studies, with 313,651 people, found a J-shaped curve for heart disease.
Risk fell slightly up to about 25 minutes of napping a day, then rose sharply with longer naps.
The newest research
Naps measured by a wristband
A 2026 study in JAMA Network Open tracked napping with a wrist device, rather than asking people. It followed 1,338 older adults, with an average age of 81, for over eight years.
Each extra hour of daytime napping was linked to a 13% higher risk of death. The authors said that’s like being about 1.1 years older.
People who napped in the morning had a higher risk than early-afternoon nappers. The links weakened in people without memory problems.
The authors suggest wearable nap data could help spot people at risk early.
Napping and brain size
A 2023 study in Sleep Health used genetic data from the UK Biobank to test whether napping itself affects the brain.
It found habitual napping was linked to a slightly larger total brain volume. The authors called it “a modest causal association”, roughly equal to 2.6 to 6.5 years of ageing.
There was no link with memory or reaction time, though.
What earlier research found
Napping and later memory decline
A 2022 meta-analysis in BMC Geriatrics pooled 25 studies of 95,719 people over 60. It found no link between napping and later decline in thinking or memory.
Napping and dementia
A 2026 study in the Journals of Gerontology of 995 older adults found frequent napping was linked to a 48% higher risk of dementia.
Unplanned napping was linked to higher risk, but planned, intentional naps weren’t. The authors suggest napping “may be a useful marker of future dementia risk”.
Not every review agrees
A 2023 meta-analysis in Sleep Medicine did find napping linked to dementia, with higher odds for longer naps.
A 2025 review in Sleep Medicine Reviews linked napping to stroke, but called the studies “very methodologically heterogeneous”.
When you can’t sleep at night
We’ve also covered research on whether a nap or exercise better protects memory after a sleepless night.
How it fits together
The pattern across studies is consistent. Short, planned naps look helpful, while long, frequent or unplanned napping may be an early sign of health problems.
How much should you trust this?
Promising. The short-term benefits are well tested. The long-term risks are clear as links, but not as causes.
What makes it convincing
- Many lab studies show the same short-term boost in alertness.
- Large cohort reviews, covering hundreds of thousands of people, agree on long naps.
- A wristband study confirmed the pattern with objective measurements.
What makes me cautious
- Most nap benefits come from lab studies, not everyday life.
- The risk findings are observational and may reflect existing illness.
- Most studies relied on people reporting their own naps.
- The heart disease results varied a lot between studies.
| The evidence shows | The evidence does not show |
|---|---|
| Short naps boost alertness for a couple of hours | That napping makes you smarter long term |
| Naps under an hour aren’t linked to higher death risk | That long naps cause disease |
| Long, frequent naps are linked to higher risks | That you should stop napping |
| Unplanned napping may be a warning sign | The perfect nap length for everyone |
What this means for you
- Keep it short. US health guidance suggests no more than 20 minutes.
- Nap early. Aim for early afternoon, and avoid late afternoon or evening naps.
- Skip naps if you have insomnia. The NHS advises people with insomnia not to nap during the day.
- Notice changes. If you start needing long or frequent naps, mention it to your doctor.
- Shift workers can use naps. The NHLBI suggests shift workers take naps to raise the time available for sleep.
The NHLBI guide to healthy sleep habits covers naps and good sleep routines.
In this short video, Mayo Clinic explains the upsides and downsides of napping:
What we still don’t know
- Do long naps cause harm? No trial has tested napping habits over years.
- What’s the ideal nap length? Guidance says 20 minutes, but studies vary.
- Does napping protect the brain? The brain-size finding is modest and needs confirming.
- Who benefits most? Shift workers and older adults may differ.
- Does timing matter? Early-afternoon naps look better, but the evidence is limited.
My take: short and early wins
What I like about this research is that it separates two very different questions.
A nap as a tool works. A nap as a habit you can’t avoid deserves attention.
I’m less convinced by headlines claiming naps shorten your life. The data point to long naps as a warning sign, not a killer.
So keep naps short and early. And if you suddenly need long ones, treat that as information worth sharing with a doctor.
Last reviewed: 2026-10-04
Covers: Whether napping is good for you, short-term benefits, health risks linked to long naps, ideal nap length and timing
Evidence: Promising — consistent short-term benefits; risks of long naps are observational links
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