Is taking an afternoon nap good for you?
An afternoon nap, also known as a siesta (Spanish origin word deriving from sexta hora or the sixth hour of daylight) is a popular sleeping pattern in many countries (Japan, Spain, Italy, Middle Eastern countries, Philippines etc). Technically known as biphasic sleep (sleep being distributed in 2 periods; one shorter sleep cycle in the afternoon and a longer one in the night), as opposed to monophasic sleep (when we sleep once during a 24 hour period at night), this pattern has been found to be the dominant pattern in pre industrialized societies. The practice of an afternoon nap originated in Italy among the Romans and was called a Riposo. Infact, in 17th century England, biphasic sleep meant people went to sleep at 9pm till 11pm, and then from 1am till dawn. The watch or the period of wakefulness between the 2 periods of sleep was productive time in which daily chores were completed and prayers offered (Ekirsch, 2022).
Cornell University Social Psychologist James Maas coined the term “Power Nap” in 1998 to encourage institutionalization of naps at work and brought forth a torrent of research on the efficacy of this powerful pattern of sleep. While the understanding of the power in the ‘power nap’ is still evolving, it’s still a powerful weapon in our sleep arsenal to warrant a short exposition.
Two major studies in Japan showed that citizens are sleep deprived and it affects their overall health and work productivity. Hence, there is a growing trend of workplace napping or “inemuri” in Japan, which allows employees to sleep in the office to recharge. They introduced the sleep pod “Giraffenap” and the afternoon pillow- “Gogo No Makura”, to facilitate these power naps. (Source- Hindustan Times, Oct 2023). This trend is not unique to Japan; Italians have the Riposo and Spaniards have siesta, while the USA has the Silicon Valley Sleepers. This is in fact encouraged by many firms and employers.
The drive for the afternoon nap comes from our circadian rhythm or our 24-hour internal body clock with a dip in the wakefulness rhythm midafternoon (2pm to 5pm) as shown in the figure.
Source: CDC
The benefits of siesta range from reducing the sleep debt in case you are sleep deprived, to improving cognitive function, productivity, regulating emotions, memory and recall, improving mood and night time sleep quality (American Heart Association).
However, the benefits that come from napping is dependent on how long you nap. Research has shown that 10 min naps are the most effective with positive effects lasting for about 155 mins after napping. These positive effects are maintained for naps lasting up to 30 mins (Brooks, Lack et al, 2006). Other researchers have found naps between 10 mins and 60 mins to be beneficial but have come to the conclusion that the 30 min nap has the best tradeoff between practicality and benefit (Leong et al, 2023). Anything beyond the 60 mins zone also propels you towards a deep sleep state which is counterproductive to the myriad benefits of the power nap.
But what happens if you nap for more than 60 mins? Well for one, you will feel groggy after waking up, will exhibit delayed response time (sleep inertia) and will have decreased quality of night time sleep. Longer nap times (above 90 mins), especially in older adults, have been shown to cause exacerbation of depression (Cross et al, 2015), higher BMI, increased risk of heart attacks (Bursztyn et al, 1999), hypertension among middle aged women (Yang et al, 2020) and increased prevalence of Non-Alcoholic Fatty Liver Disease or NAFLD (Qu et al, 2014).
While the jury is still out on the benefits of an afternoon nap, in the meantime, take a quick power nap (of up to 30 mins) to improve your physical and cognitive abilities. However, do make sure that you,
Nap early than late in the afternoon (before 3 pm)
Prepare for a window of approximately 45 mins (15 mins to fall asleep) in the afternoon
Find a calm and quiet place to nap
Set an alarm for 30 -45 mins
Happy Napping!
References:
The forgotten medieval habit of ‘two sleeps (bbc, 2022)
AT DAY’S CLOSE: A HISTORY OF NIGHTTIME (Ekirch, 2022)
Brooks A, Lack L. A brief afternoon nap following nocturnal sleep restriction: which nap duration is most recuperative? Sleep. 2006 Jun;29(6):831-40. doi: 10.1093/sleep/29.6.831. PMID: 16796222.
Take a Nap: The Benefits of Napping and How to Make It Work for You (Heart.org)
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 Apr 12;46(4):zsad025. doi: 10.1093/sleep/zsad025. PMID: 36775965; PMCID: PMC10091091.
Cross N, Terpening Z, Rogers NL, Duffy SL, Hickie IB, Lewis SJ, Naismith SL. Napping in older people ‘at risk’ of dementia: relationships with depression, cognition, medical burden and sleep quality. J Sleep Res. 2015 Oct;24(5):494-502. doi: 10.1111/jsr.12313. Epub 2015 Jun 21. PMID: 26096839.
Yang Y, Liu W, Ji X, Ma C, Wang X, Li K, Li J. Extended afternoon naps are associated with hypertension in women but not in men. Heart Lung. 2020 Jan-Feb;49(1):2-9. doi: 10.1016/j.hrtlng.2019.09.002. Epub 2019 Sep 11. PMID: 31521340; PMCID: PMC6961342.
Bursztyn M, Ginsberg G, Hammerman-Rozenberg R, Stessman J. The siesta in the elderly: risk factor for mortality? Arch Intern Med. 1999 Jul 26;159(14):1582-6. doi: 10.1001/archinte.159.14.1582. PMID: 10421281.