A nap of 30 minutes or less looks like the safer length. In a Sleep Health study published online 21 October 2026, 4,447 older adults in Vietnam reported their naps. Only regular naps of an hour or more were linked with higher odds of dying within 4 years, about 39% higher than not napping; short naps were not.
Key takeaways
- A cohort study in Sleep Health (Chen, Le, Buxton, Vu and Saito, published online 21 October 2026) followed 4,447 adults in Vietnam with an average age of about 70 for 4 years.
- Two in three of them napped, regularly or as needed; 514 (12%) died during follow-up.
- Only regular naps of 60 minutes or more were linked with higher odds of death, about 39% higher than not napping, after accounting for night sleep health; regular naps under 30 minutes were not.
- The finding matches a 2015 meta-analysis of 11 cohorts (151,588 people), in which naps of 60 minutes or more a day were linked with 27% higher all-cause mortality and shorter naps were not.
- The one change: cap your nap at 20 to 30 minutes, set an alarm, and take it in the early afternoon.
What did the 2026 napping study find?
Long, regular naps stood apart; short naps did not. Among older adults in Vietnam, taking an hour-plus nap as a habit was linked with about 39% higher odds of dying within 4 years compared with not napping, even after the researchers accounted for how well people slept at night.
Tzu-Ying Chen of Academia Sinica, Orfeu Buxton of Penn State and colleagues used the Longitudinal Study of Ageing and Health in Vietnam (2018 to 2023). At baseline, 4,447 adults (average age 69.7, 55.5% women) described their naps, which the team sorted by length (under 30 minutes, 30 to 59 minutes, 60 minutes or more) and by habit (regular or only as needed). Night sleep health was scored on four dimensions, from sleep satisfaction to duration.
| Nap habit | Odds of death over 4 years, compared with not napping |
|---|---|
| Regular, under 30 minutes | no significant difference |
| Regular, 30 to 59 minutes | no significant difference |
| Regular, 60 minutes or more | about 39% higher |
| As needed, any length | no significant difference on its own |
Night sleep mattered too. Poorer night sleep was linked with a higher probability of death for most nap types, but not for regular short nappers; regular long nappers stayed high whatever their night sleep.
Why would a long nap be linked with dying sooner?
Nobody knows yet, and the nap may be a signal rather than a cause. Long daytime sleep can reflect broken night sleep, low activity, depression or an illness that has not been diagnosed, and a 4-year observational study cannot separate those from the nap itself.
The pattern does repeat across studies. A 2015 dose-response meta-analysis in Sleep (Yamada and colleagues, University of Tokyo) pooled 11 prospective cohorts with 151,588 participants. Naps of 60 minutes or more a day were linked with 27% higher all-cause mortality and 82% higher cardiovascular disease risk compared with no nap, while naps under 60 minutes were not linked with either. For heart disease the curve was J-shaped: risk fell from 0 to 30 minutes a day, rose slightly to about 45 minutes, then climbed sharply with longer naps.
In Spain, where the siesta is part of the culture, a 2023 cross-sectional Obesity study of 3,275 adults found that siestas over 30 minutes were linked with higher body mass index and a 41% higher prevalence of metabolic syndrome than no siesta, while siestas of 30 minutes or less were linked with a 21% lower chance of elevated systolic blood pressure.
How long should a nap be?
About 10 to 20 minutes, and no more than 30. That length gives light sleep without dropping into deep sleep, which is what leaves people groggy on waking.
A classic laboratory study in Sleep (Brooks and Lack, Flinders University, 2006) restricted 24 young adults to about 5 hours of night sleep, then tested afternoon naps of 5, 10, 20 and 30 minutes. The 10-minute nap gave immediate gains in alertness and performance, some lasting up to about 2.5 hours; the 20-minute nap’s benefits appeared after about 35 minutes; the 30-minute nap first caused a stretch of grogginess (sleep inertia). The US National Heart, Lung, and Blood Institute advises adults to nap no more than 20 minutes and, for anyone who has trouble falling asleep at night, to limit naps or take them earlier in the afternoon.
What are the limits of the 2026 study?
It is observational, with naps self-reported once at baseline, in older adults in one country. A habit of long naps may mark health problems already present, and the study does not show that shortening a nap lengthens life.
What is the one change to make?
Cap your nap at 20 to 30 minutes and set an alarm before you lie down. Take it in the early afternoon, when the body clock brings a natural dip in alertness, and finish it at least eight hours before bedtime; for most people that means before 3 PM.
- Put the nap in your plan as its own short block, right after lunch, so it has an end time.
- Rest in a chair or on a sofa with low light rather than getting into bed.
- If you are reaching for an hour-long nap most days, look at the night first. See How to Fix Your Sleep Schedule: Anchor, Light, 15 Min.
- Keep afternoon coffee from fighting your night sleep: Caffeine Cutoff Time: When to Have Your Last Coffee.
- Working nights changes the rules on naps; see Night Shift Schedule: How to Plan Sleep, Meals and Light.
For the wider picture of sleep among the pillars of health, see Pillars of Lifestyle Medicine: 15 Frameworks Compared. Curious when your own body clock dips? Take the Body Clock Type quiz.
Your day on My BodyClock
The day above on My BodyClock shows a weekday built around a 20-minute nap. Sleep runs from 10:30 PM to 6:30 AM, 8 hours. A morning walk in daylight and breakfast lead into focused work, then lunch at 12:30 PM. At 1:15 PM a 20-minute Relax block holds the nap, with an alarm, finishing well before 3 PM and more than eight hours before bed. The afternoon has work, a bike ride, an early dinner and an evening with family before a wind-down with a book.
Add a nap block with its own alert and build your version in Owaves: My BodyClock on the App Store, or join the Android waitlist.
FAQ
How long should a nap be for adults?
Keep it short. The US National Heart, Lung, and Blood Institute advises adults to nap for no more than 20 minutes, and the Sleep Foundation puts the usual range at 20 to 30 minutes. In a 2026 study of 4,447 older adults, regular naps under 30 minutes were not linked with higher odds of death.
Are long naps bad for you?
Regular naps of an hour or more have been linked with higher mortality in several studies, including a 2026 study in Vietnam (about 39% higher odds over 4 years) and a 2015 meta-analysis of 151,588 people. These are associations: a long nap may be a sign of poor night sleep or illness rather than a cause of harm.
What is the best time of day to nap?
Early afternoon, during the post-lunch dip in alertness. The Sleep Foundation suggests napping eight or more hours before bedtime, which for most people means before 3 PM, so the nap does not push back sleep at night.
Sources
- Chen TY, Le TM, Buxton OM, Vu NC, Saito Y. Is napping harmless? Nighttime sleep health and all-cause mortality in community-dwelling older Vietnamese adults. Sleep Health, published online 21 October 2026. doi:10.1016/j.sleh.2026.09.004. https://pubmed.ncbi.nlm.nih.gov/42907246/
- Yamada T, Hara K, Shojima N, Yamauchi T, Kadowaki T. Daytime Napping and the Risk of Cardiovascular Disease and All-Cause Mortality: A Prospective Study and Dose-Response Meta-Analysis. Sleep, 2015;38(12):1945-1953. doi:10.5665/sleep.5246. https://pubmed.ncbi.nlm.nih.gov/26158892/
- Vizmanos B, Cascales AI, Rodríguez-Martín M, et al. Lifestyle mediators of associations among siestas, obesity, and metabolic health. Obesity, 2023;31(5):1227-1239. doi:10.1002/oby.23765. https://pubmed.ncbi.nlm.nih.gov/37140401/
- Brooks A, Lack L. A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative? Sleep, 2006;29(6):831-840. doi:10.1093/sleep/29.6.831. https://pubmed.ncbi.nlm.nih.gov/16796222/
- National Heart, Lung, and Blood Institute. Healthy Sleep Habits. https://www.nhlbi.nih.gov/health/sleep-deprivation/healthy-sleep-habits
- Sleep Foundation. Napping: Benefits and Tips. https://www.sleepfoundation.org/sleep-hygiene/napping
Photos: MUSIC_AND_WALLPAPER / Pixabay · FREEDOM_Ai_Studio / Pixabay · epicioci / Pixabay · romjanaly / Pixabay · ahmetyuksek / Pixabay · KIMDAEJEUNG / Pixabay · Nowaja / Pixabay · stevepb / Pixabay