How to Take the Perfect Power Nap (backed by science)
Want a drug-free way to boost your brain performance, mood, and even athletic function? Sleep is, of course, the answer, but in the form of a strategic power nap.
Brain benefits of naps
Immediate (acute) cognitive benefits of naps.
A large meta-analysis of 54 studies examined the results of cognitive tests related to afternoon napping. Across age groups and regardless of whether people were habitual nappers, naps improved memory (both declarative and procedural), vigilance, and processing speed. (Leong 2022)
In older adults (age >50), pooled analysis of 35 studies showed that short or moderate (45-60minute) naps were associated with better cognitive function, compared to none or long (>1 hour) naps. (Li 2023)
Similarly, another pooled analysis of older adults (age 60-78) showed that naps were associated improvements in fatigue, cognitive abilities, and psychomotor speed and accuracy. (Souabni 2022)
Long-term health and cognitive effects of naps.
A very large meta-analysis study, including 1.86 million participants aged 20-86, found that habitual napping was associated with increased risk of death, cardiovascular disease, metabolic disease, and cancer. But, naps were associated with decreased risk of cognitive impairment and sarcopenia (muscle loss). Importantly, the increased risk of death and the other bad health effects disappeared when naps were <30 minutes. (Yang 2024)
Naps improve physical performance
Naps have restorative benefit for the rest of the body as well: if you’re an athlete or just want a physical boost, a strategic nap can boost athletic performance.
A large meta-analysis looked at 22 clinical trials involving 291 participants. Napping improved physical performance, cognitive performance (especially important for competitive sports), and perceived fatigue. (Mesas 2023).
Athletic benefits of napping were maximal when
The nap was 30-60 minutes
There was at least 1 hour between waking up and the physical activity.
Notably, napping helped athletic performance whether or not a person was sleep deprived the night before.
How long should I nap?
The key trade-off for the cognitive and physical benefit of naps is sleep inertia — the grogginess and impaired performance that happens when you wake up from a deeper sleep.
To find the right balance of nap cognitive benefit vs sleep inertia, a carefully-controlled study tested after-lunch naps of 0, 10, 30, and 60 minutes in young men who were habitual short sleepers. Nap duration was defined by actual sleep time measured by polysomnography, not just time in bed. Only the 30-minute nap improved memory performance. (On average, 30 minutes of sleep required 44 minutes in bed.) While sleep inertia occurred after both 30- and 60-minute naps, it resolved within about 30 minutes. All nap durations improved mood and reduced sleepiness. (Leong 2023)
Long-term studies of older adults also consistently show that naps are beneficial only if they are short or moderate in length. In the large (1.86 million people) meta-analysis mentioned above, naps under 30 minutes eliminated the potential adverse health associations (Yang 2024).
Bottom line: When all the data are considered together, the ideal nap length is ~30 minutes of sleep. If it takes you 10-15 minutes to fall asleep, you can add that time…but if you wake up feeling groggy, your naps are too long. Experiment to find a time that works best for you.
What’s the best time to take a nap?
Ideal nap timing is covered by the interaction between sleep drive and the circadian (internal clock) system.
Sleep drive (or sleep pressure) builds up the longer you are awake, and quickly dissipates as soon as you go to sleep. Meanwhile, the circadian system produces a natural dip in alertness in the early afternoon, followed by rising alertness later in the day.
To take advantage of both systems, the best time to take a nap is after lunch in the early afternoon. At this time, you have both some sleep drive and circadian dip to help you fall asleep, but you have plenty of time to build up sleep drive for your nighttime sleep.
If you take a nap too late in the day, you’re at risk of trouble falling asleep at bedtime. You will also be missing out on your best, most alert hours.
Why naps should be intentional
Effective naps are planned, not accidental.
Accidental dozing while watching tv in the evening is not a high-quality nap, and signals you are not getting sufficient (quantity or quality) sleep at night. Falling asleep unintentionally (even for a split second) while driving, working, conversing, or eating, is a serious symptom of pathological sleepiness and should not be ignored.
An intentional, scheduled nap allows you to create a sleep-conducive environment, just like you would for nighttime sleep. The ideal nap is taken in a dark, quiet, cool, and calm setting.
Are some people better nappers than others?
Unfortunately, yes.
Some people have high “sleepability” (seriously, a real term in sleep medicine): they fall asleep easily. Sleep ability is likely influenced by genetics, stress levels, sleep schedules, and other factors.
If you have insomnia at night, do not try to take naps. Napping can worsen insomnia by reducing nighttime sleep drive, and increasing frustration. It’s best to conserve sleep drive for the nighttime.
Good nappers can also wake up relatively easily, ie don’t get “sleep inertia” too quickly during their naps.
If you don’t know if you’re a good napper or not: try it once or twice. If you’re not asleep by the time the alarm goes off, or you wake feeling super groggy, napping is probably not for you at this time.
Caffeine naps (optional)
One strategy to reduce sleep inertia is the “caffeine nap” or “coffee nap”.
Caffeine effects start about 10-45 minutes after taking it, and peaks in about 1-2 hours.
In theory, having a small serving of caffeine immediately before your nap allows the stimulant effect to start around the time you wake up, reducing grogginess.
However, results vary widely. Caffeine has a half-life of 4-6 hours, but some people metabolize caffeine slower, or are highly sensitive even to very low levels of caffeine in their system. Some people have trouble sleeping at night even 10+ hours after their last caffeine dose. If caffeine interferes with your nighttime sleep, skip the caffeine.
Summary: Tips for the perfect power nap
Intentionality: Nap on purpose, in a quiet, dark, and calming environment. Accidental dozing is not restorative.
Timing: End naps by 3pm. If you are a true night owl, naps should end 6-7 hours before your bedtime.
Duration: Keep naps 30 minutes or less. Set an alarm and stick to it.
Person: Naps work best for people who can fall asleep and wake up easily. If you have insomnia, avoid naps.
Caffeine (Optional): A small dose before nap may reduce sleep inertia, but try it only if caffeine doesn’t disturb your nighttime sleep.
References:
Leong RLF, Lo JC, Chee MWL. Systematic review and meta-analyses on the effects of afternoon napping on cognition. Sleep Med Rev. 2022;65:101666. doi: 10.1016/j.smrv.2022.101666. Pubmed.
Leong RLF, Lau T, Dicom AR, Teo TB, Ong JL, Chee MWL. Influence of mid-afternoon nap duration and sleep parameters on memory encoding, mood, processing speed, and vigilance. Sleep. 2023;46(4):zsad025. Pubmed.
Li J, McPhillips MV, Deng Z, Fan F, Spira A. Daytime Napping and Cognitive Health in Older Adults: A Systematic Review. J Gerontol A Biol Sci Med Sci. 2023 ;78(10):1853-1860. Pubmed.
Souabni M, et al. Benefits and risks of napping in older adults: A systematic review. Front Aging Neurosci. 2022 Oct 21;14:1000707. Pubmed.
Yang YB et al. To nap or not? Evidence from a meta-analysis of cohort studies of habitual daytime napping and health outcomes. Sleep Med Rev. 2024 ;78:101989. Pubmed.
