Ein kurzes Nickerchen von zehn bis zwanzig Minuten, eingenommen am frühen Nachmittag, steigert Wachheit, Stimmung und Denkvermögen für einige Stunden und kostet nichts. Halten Sie es so kurz, und Sie wachen munter auf. Schlafen Sie länger als etwa dreißig Minuten, können Sie eine Weile benommen aufwachen, ein Zustand, der als Schlafträgheit bezeichnet wird. Schlagzeilen verknüpfen Nickerchen mit Herzkrankheiten und frühem Tod.
Doch diese Studien beobachteten lange, häufige Nickerchen bei Menschen, die bereits ungesund waren, sodass die Erkrankung das Nickerchen verursacht. Ein Nickerchen ist eine gute Auffrischung nach einer kurzen Nacht. Es wurde nicht gezeigt, dass es einen über Wochen angesammelten Schlafmangel ausgleicht, und für jeden, der an Insomnie arbeitet, kann es die nächste Nacht schwieriger machen.
Findings & Outcomes
What It Is
A nap is a short sleep taken during the day, most usefully in the early afternoon. It is one of the few free things that measurably improve the next few hours. Cultures around the Mediterranean and Latin America have built it into the day for centuries.
A brief deliberate nap in a rested person adds a little to a good night. Long or frequent daytime sleep, the kind you cannot easily avoid, more often signals that night sleep is failing or that an underlying illness is present. Research treats the two apart.
What It Does
A 10-to-20-minute nap in the early afternoon sharpens attention, mood and reasoning for about two hours, the effect measured in controlled trials. It is the core of the practice.
A nap past 30 minutes consolidates a skill you learned earlier that day, and it leaves you groggier on waking. The caffeine nap pairs the short nap with coffee, for the times you must be alert the instant you stand up.
The alarming numbers come from a different kind of study. Observational cohorts that follow large groups for years tie long, frequent naps to more heart disease and earlier death. They cannot separate the nap from the illness that usually causes it.
A British cohort of 16,374 adults found the extra deaths clustered in respiratory illness, a sign of disease already present (Leng 2014).
The Research & Studies
Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.
Cognition
A 10-minute afternoon nap lifted alertness, mood and thinking, with gains lasting up to 155 minutes
A ten-minute afternoon nap made people more alert, clearer-thinking and better in mood almost as soon as they woke, with hardly any grogginess, while a thirty-minute nap left them foggy for a while first.
After a night restricted to about 5 hours, a 10-minute afternoon nap produced immediate improvements in sleep latency, subjective sleepiness, fatigue, vigor and cognitive performance, some lasting up to 155 minutes. The 5-minute nap gave few benefits, the 20-minute nap helped from about 35 minutes after waking, and the 30-minute nap caused a spell of sleep inertia before improving. Measured in: 24 healthy young adults who were good sleepers and not regular nappers, tested in a repeated-measures crossover of no nap and naps of 5, 10, 20 and 30 minutes at 3 pm. Small, within-subject laboratory study in young good-sleeper non-nappers after one restricted night, so it may not transfer to older adults, habitual nappers or a normal night. The sex breakdown was not reported in the paper.
Keep the nap to about ten to twenty minutes so you wake alert.
The study · 1
Brooks and Lack, a brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative? · Sleep 2006;29(6):831-40
Keeping a nap under 30 minutes does not reliably prevent sleep inertia
The rule that a nap under half an hour will always leave you free of grogginess does not hold up neatly; whether you wake clear depends on how short you were on sleep and the time of day, not just on nap length.
The widely repeated advice that a nap of 30 minutes or less avoids sleep inertia is not cleanly supported. Studies show mixed results on the onset of slow-wave sleep and on the duration and severity of inertia after short naps, and the differences track with prior sleep and wake history and the time of day at waking, so a blanket duration rule is only a rough guide. Measured in: Review of studies of naps of 30 minutes or less in relation to sleep inertia and slow-wave sleep, with very few studies of short naps taken at night. A narrative review, not a pooled estimate, and it highlights that short-nap guidance depends on context that most rules of thumb leave out. Sex composition across the reviewed studies was not summarized.
Treat the under-thirty-minute rule as a useful default, not a promise, and give yourself a few minutes to shake off any grogginess.
The study · 1
Hilditch, Dorrian and Banks, a review of short naps and sleep inertia: do naps of 30 min or less really avoid sleep inertia and slow-wave sleep? · Sleep Med 2017;32:176-190
A 60 to 90 minute nap locked in a visual skill as well as an 8-hour night of sleep
A nap of about an hour to ninety minutes locked in a newly learned visual skill just as well as a full night of sleep, though this needed a longer nap than the short one that keeps you from waking groggy.
A 60 to 90 minute daytime nap containing both slow-wave and REM sleep consolidated learning of a visual texture-discrimination task as much as an 8-hour night of sleep, matching it in magnitude and sleep-stage dependency, and the nap-driven gain added to further improvement after the following night. Measured in: Healthy adults trained on a visual texture-discrimination task and tested after a daytime nap containing slow-wave and REM sleep versus no nap. A single perceptual-learning task in a small experimental study, so it does not show naps improve memory in general. This benefit needed a long nap of 60 to 90 minutes, which trades the memory gain against the grogginess a short nap avoids. The sex breakdown was not reported.
If the goal is to cement something you just learned, not to feel sharp right away, a longer nap through both deep and dreaming sleep is the trade-off to know about.
The study · 1
Mednick, Nakayama and Stickgold, sleep-dependent learning: a nap is as good as a night · Nat Neurosci 2003;6(7):697-8
Heart And Vascular
Naps of 60 minutes or more track with more cardiovascular disease (rate ratio 1.82) and death (1.27); shorter naps show no link
Naps of an hour or more were tied to more heart disease and earlier death across large studies, but short naps were not, and much of the long-nap link is because being unwell makes people nap a lot, not the other way around.
Pooling 11 prospective cohorts, a long daytime nap of 60 minutes or more was associated with higher cardiovascular disease (rate ratio 1.82, 95% CI 1.22 to 2.71) and higher all-cause mortality (RR 1.27, 95% CI 1.11 to 1.45) compared with not napping, while napping under 60 minutes showed no association with either. The dose-response for cardiovascular disease was J-shaped, dipping from 0 to about 30 minutes before rising at longer nap times. Measured in: 151,588 participants across 11 prospective cohort studies, 60% women, mean follow-up 11 years, with 5,276 cardiovascular events and 18,966 all-cause deaths. What could explain it instead: Reverse causation is the leading explanation: illness, frailty and poor night sleep all cause long daytime napping, so the long nap is often a marker of ill health, not a cause of it. Residual confounding by undiagnosed disease is plausible even in the well-adjusted studies selected.. Observational cohorts, so this maps association, not cause. Short naps carried no excess risk, and the harm signal is confined to long naps. Nap duration was self-reported in most contributing studies.
A short nap carries no excess risk in this data; a persistent need for hour-long daytime sleep is worth raising with a doctor.
The study · 1
Yamada, Hara, Shojima, Yamauchi and Kadowaki, daytime napping and the risk of cardiovascular disease and all-cause mortality: a prospective study and dose-response meta-analysis · Sleep 2015;38(12):1945-53
Napping once or twice a week tracks with about half the cardiovascular risk (hazard ratio 0.52)
People who took a nap once or twice a week had about half the heart-attack and stroke risk of people who never napped, and napping more often than that neither helped nor harmed once other health differences were accounted for.
Over a mean 5.3 years, people who napped once or twice a week had a lower risk of a fatal or non-fatal cardiovascular event than non-nappers (hazard ratio 0.52, 95% CI 0.28 to 0.95) after adjustment for cardiovascular risk factors, daytime sleepiness and sleep apnea. The raised crude risk in the most frequent nappers (6 to 7 times a week) disappeared after adjustment, and nap duration showed no association with events. Measured in: 3,462 adults in a Swiss population-based cohort with no prior cardiovascular disease, nap frequency and duration reported over a week, followed a mean 5.3 years with 155 events. What could explain it instead: Frequent nappers differ from occasional ones in underlying health, sleepiness and sleep apnea; adjusting for these removed the apparent risk of frequent napping but cannot rule out residual confounding by unmeasured illness in either direction.. Observational, with 155 events over the period, so estimates are imprecise. It suggests nap frequency, not duration, explains much of the conflicting findings on napping and heart disease.
An occasional short nap is not something to fear for the heart; the frequency and the reason behind heavy daily napping matter more than the nap itself.
The study · 1
Häusler, Haba-Rubio, Heinzer and Marques-Vidal, association of napping with incident cardiovascular events in a prospective cohort study · Heart 2019;105(23):1793-1798
Energy And Fatigue
In healthy adults, naps improve alertness and performance, most in the early afternoon at short lengths
Naps make healthy people more alert and sharper, and how much they help depends on how long you sleep, what time of day it is, your age, and whether you are a regular napper.
In healthy adults on regular sleep schedules, naps improve alertness and performance, and the size of the benefit depends on nap length, the time of day it is taken, the persons age, and whether they are used to napping. The early-afternoon window and short-to-moderate durations recur as the conditions under which naps help most with the least grogginess. Measured in: Review of laboratory and field studies of daytime napping in healthy individuals with regular sleep and wake schedules, excluding sleep and medical disorders. A narrative review focused on healthy regular sleepers, so it does not speak to people with sleep disorders, and it summarizes varied study designs, not pooling them. Sex composition across the studies was not tabulated.
Aim for a short nap in the early afternoon; if you rarely nap, expect the first few to feel less useful than they will once the habit settles.
The study · 1
Milner and Cote, benefits of napping in healthy adults: impact of nap length, time of day, age, and experience with napping · J Sleep Res 2009;18(2):272-81
Sleep
A nap restores alertness after a short night; whether it repays a chronic sleep debt is not yet established
A nap recovers some alertness and steadiness after a short night. Whether it can repay a sleep debt built up over weeks has not been shown.
Reviewed across epidemiological and laboratory studies, napping acts as a countermeasure to sleep loss, restoring alertness and sleep-restriction-sensitive performance and buffering some of the stress, immune and pain changes caused by cutting sleep. Its value depends on nap duration, frequency and age, and its role in people with chronic sleep debt such as shift workers still needs evaluation. Measured in: Review spanning epidemiological and laboratory studies of napping as an action against sleep deprivation, covering accidents, work and school performance, cardiovascular risk, cognition, stress, immune function and pain. A narrative review framing napping as a recovery tool for acute sleep loss; it notes that the effect on chronic sleep debt is not yet established. A nap reliably tops up a short night; whether it clears a standing debt has not been tested.
Use a nap to take the edge off one short night; fix the nights themselves if the shortfall is ongoing.
The study · 1
Faraut, Andrillon, Vecchierini and Leger, napping: a public health issue. From epidemiological to laboratory studies · Sleep Med Rev 2017;35:85-100
Longevity And Mortality
Daytime napping tracks with higher 13-year mortality (hazard ratio 1.14 under an hour, 1.32 at an hour or more), concentrated in respiratory deaths
In a large British study, people who napped in the day were somewhat more likely to die over the next 13 years, but the extra deaths were mostly from lung disease and among younger adults, which suggests the napping was a sign of hidden illness, not its cause.
Over 13 years, daytime napping was associated with higher all-cause mortality: hazard ratio 1.14 (95% CI 1.02 to 1.27) for napping under 1 hour a day and 1.32 (1.04 to 1.68) for 1 hour or more, adjusted for a wide set of health and lifestyle factors. The association was strongest for death from respiratory disease (HR 2.56, 1.34 to 4.86 for naps of an hour or more) and in people aged 65 or younger. Measured in: 16,374 men and women in the EPIC-Norfolk cohort who answered questions on napping habits between 1998 and 2000, with 3,251 deaths over 13 years. What could explain it instead: Reverse causation is explicit here: the excess deaths concentrated in respiratory illness and in the under-65s point to undiagnosed disease driving the daytime napping. Adjustment for preexisting conditions and self-rated health narrowed but did not remove this.. Observational, with napping reported by questionnaire once at baseline. The authors read excessive napping as a marker of underlying health risk, particularly respiratory, not a cause of death.
Read a strong pull to nap in the day, especially alongside breathlessness or new symptoms, as a reason for a check-up, not a health habit gone wrong.
The study · 1
Leng et al., daytime napping and the risk of all-cause and cause-specific mortality: a 13-year follow-up of a British population · Am J Epidemiol 2014;179(9):1115-24
How It Works
Adenosine builds in the brain the longer you are awake and creates the drive to sleep; it falls once you sleep. The body clock adds a second pull. Its alerting signal dips between about 1 and 3 p.m., so the afternoon lull runs on the clock, not on lunch (Milner & Cote 2009). A nap in that window sheds enough of the built-up pressure to restore alertness without dropping you into deep sleep, so you wake clear.
Stay asleep past roughly thirty minutes and you drop into deep slow-wave sleep. Being woken out of it produces sleep inertia, the grogginess and slowed thinking that can last from a few minutes to half an hour. Its strength tracks the time of day you wake and how short of sleep you were beforehand, not nap length alone (Hilditch 2017).
A nap also spends the sleep pressure that builds toward the coming night, so a long or late one can make falling asleep harder. After a single short night a nap restores alertness well, but whether it offsets a deficit accumulated over weeks has not been established (Faraut 2017).
Anatomy of the Practice
1The nap itself
For roughly the first twenty minutes you stay in light sleep. That is where the alertness comes from, and waking is quick and easy. Sleep past about twenty-five or thirty minutes and you cross into deep slow-wave sleep, where waking leaves the first stretch foggy.
2The hour after
A short nap clears the sleepiness that has built across the afternoon, and alertness and mood lift within minutes and hold for the next hour or two. A longer nap can leave you foggy for ten to thirty minutes first, then clears.
3As a habit
A brief regular nap settles into the day as an ordinary habit for many people, common and unremarkable into old age.
Getting the Nap Right
The mechanism points to one move, a short nap, taken early.
Ways to Do It
The whole practice is free. The version that works is short and early: set an alarm so you wake before deep sleep, and take it in the early afternoon.
Set an alarm for twenty minutes and lie down in the early afternoon. That keeps you in light sleep, short of the deep stage, so you wake alert. This one habit is the practice.
Drink a coffee, then lie down for fifteen to twenty minutes. Caffeine takes about that long to reach the brain, so you wake as it starts to work and get both lifts at once. Drivers and shift workers are taught this version.
You fall asleep faster reclined than slumped at a desk, and darker and quieter is faster still. An eye mask and earplugs cost little, pack small, and block a bright or noisy room.
The aim is a brief nap you can drop into almost any afternoon. Two routes, one free and one that costs a little.
An alarm on the phone, a dark corner, and a reclined position. That is the whole method.
An eye mask, a pair of earplugs, and if you nap at a desk a reclining chair. Small, one-time, and they darken and quiet a room that is too bright or loud.
Go Deeper
A nap covers a short night. It does not replace the steady sleep that a regular schedule builds. Hold a steady sleep and wake time with sleep regularity, and get morning light soon after you wake. If you are treating insomnia, CBT-I is the first-line method. To fall asleep faster in the minutes you have, work on the sleep environment. The caffeine nap leans on caffeine.
The Chinese Medicine View
子午觉, the Zi and Wu rest, is a classical health-preservation teaching. It pairs deep sleep at the Zi hour around midnight with a short rest at the Wu hour around noon. These are the two turns of the day when Yin and Yang change over.
The noon rest is meant to stay brief, a short settling of the Heart and no more. It sits inside 養生 (Yang Sheng), the tradition of nourishing life by living with the rhythms of the day.
At noon the Heart channel is said to be at its peak. A short quiet pause is read as a way to calm the 神 (Shen), the spirit housed by the Heart, before the afternoon.
A long daytime sleep is held to dull the Yang and let damp and phlegm gather. Someone who runs to phlegm-damp, or whose Spleen Qi is weak, shows it as heavy limbs, fog, loose stools and a thick tongue coat. Such a person is often told to keep the noon rest very short, or to sit up instead of lying down.
Waking heavier than before a nap is read the same way, as the Yang failing to rouse. This is close to what modern sleep science calls sleep inertia, though tradition and laboratory describe it in different terms.
The classics prize a short noon rest and warn against a long one. The laboratory data show the same shape: a brief early-afternoon nap helps, a long one leaves you groggy. A practitioner who reads your constitution can judge how long a rest suits you, or whether it suits you at all.
Cautions For This Practice
Everything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.
Coffee then a short nap cut sleepy-driver incidents to 9% of placebo, versus 34% for caffeine alone
In sleepy drivers on a 2-hour monotonous afternoon simulated drive, 200 mg of caffeine taken with a short nap during a 30-minute break reduced driving incidents to 9% of placebo levels, compared with 34% for caffeine alone, and eliminated the mid-afternoon peak in subjective and EEG sleepiness that caffeine alone only reduced. Small crossover in a driving simulator, not on the road, and the nap included light dozing, not confirmed sleep. The sex breakdown was not reported in the paper.Reyner and Horne, suppression of sleepiness in drivers: combination of caffeine with a short nap
If you are working on insomnia, skip the daytime nap
A nap discharges the sleep pressure you want banked for the night. For anyone treating insomnia the usual guidance is no naps at all; CBT-I drops them for this reason. If you cannot get through the day without one, keep it very short and take it before mid-afternoon.
Let sleep inertia clear before driving or precise work
Waking from a longer nap can leave you briefly slower and clumsier than before you lay down. Give yourself fifteen to twenty minutes, some light and a little movement before driving or precise work. When you must be sharp straight after, take a short nap or the caffeine nap.
New or heavy daytime sleepiness: see a doctor
Needing long naps despite a full night, or a sudden new pull to sleep in the day, can point to sleep apnea, an underactive thyroid, depression, anemia or other conditions. The right move is a check-up.
Older adults and a short regular nap
A brief habitual nap is common and normal with age, and there is no need to fear it. The signal to watch is a clear rise in how much daytime sleep you need; that rise is what points to a problem.
Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.
Common Questions
How long should a nap be, and when?
When researchers compared naps of five, ten, twenty and thirty minutes after a short night, the ten-minute nap gave immediate gains in alertness, mood and cognition. Grogginess was almost nil, while the thirty-minute nap brought a spell of sleep inertia first (Brooks & Lack 2006). Take it in the early afternoon.
Is napping bad for your heart or your lifespan?
For most people, a short nap is not. Adults who napped once or twice a week showed lower cardiovascular risk, not higher (Häusler 2019).
Will a nap wreck my sleep tonight?
Usually not, if it is short and early. A brief early-afternoon nap leaves the night intact for most good sleepers; a nap taken late or run long is what pushes bedtime back.
What is a caffeine nap?
Pairing a coffee with a short nap beats either alone. In sleepy drivers on a dull afternoon drive, coffee plus a short nap cut driving incidents to about 9% of placebo, against 34% for caffeine alone (Reyner & Horne 1997).
Explore Related
Other pages this one connects to, by the evidence they share, the outcomes they touch, and the ground they cover.
All 9 sources on this page independently checked and cross-referenced.
Thomas Dehli, Founder & Editor, Sacred Lotus
Sacred Lotus has published Chinese medicine reference material since 2001. Integrative pages are held to the same standard as the herb and formula library: cite the source, grade the claim at its real strength, and say where the research has not looked. This page is educational and it is not medical advice. Last reviewed and updated August 8, 2026.
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