Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
A Nap a Day Keeps the Doctor at Bay | What Does Napping Mean for You? |
The Best Time to Nap | What’s the Bottom Line?
Overview
Sleep specialists have spent considerable time attempting to unveil the so-called “secrets” behind optimal sleep.
Questions such as “How much sleep do you need?” and “How do you get restorative sleep?” have been answered, though as with most things in healthcare, the results found can’t be translated into generalized advice that applies to every individual.
Against this backdrop, two recent studies looking into the relationship between sleep and brain health were published.
Researchers found that not getting the recommended daily amount of sleep – around 7-8 hours per night for adults – may not be as harmful to your brain as you think.[1][2]
However, since sleep medicine is still a newish field, more research must be done to make these findings concrete.
We’re here to break down the effects of napping on your brain volume and dissect what you need to look out for going forward to ensure you’re getting the rest your body craves.
A Nap a Day Keeps the Doctor at Bay
Your brain’s volume is measured using magnetic resonance imaging (MRI) scans.
Larger brain volumes are correlated with greater intelligence, whereas smaller brain volumes are linked to neurodegeneration and cognitive disease progression.[3][4]
Your brain volume is expected to shrink as you progress through life.[2] However, certain conditions, including those attributed to sleep, may accelerate this degeneration.
This finding has been evident from studies demonstrating the correlation between smaller brain volumes and insomnia.[5]
Following this, further research has found that reduced daytime napping leads to an increased Alzheimer’s risk.[6] These studies found that those who napped more frequently had higher brain volumes, suggesting that getting in those couple of extra hours of sleep per day can provide some protection against neurodegeneration.[2]
What Does Napping Mean for You?
So, what does this mean for you and your sleep habits? Should you start scheduling naps into your daily routine? Well, not necessarily.
While napping may benefit brain health, it’s not a magic bullet that can reverse or prevent cognitive decline.[2]
Many other factors, such as diet, exercise, stress, genetics, and environmental exposures, influence your brain health.[7]
Moreover, napping too much or at the wrong time can negatively affect your sleep quality and quantity at night.[8]
Napping too close to bedtime can interfere with your circadian rhythm and make it harder to fall or stay asleep.[8]
Finally, napping too long can also cause sleep inertia, which is a feeling of grogginess and disorientation that can impair your alertness and performance for a while after waking up.[9]
The Best Time to Nap
Despite new evidence demonstrating the protective benefits of napping on brain volume, it’s essential to follow some guidelines to ensure you’re napping properly.
Various studies suggest that the best time to nap is in the early afternoon, between 1 p.m. and 3 p.m. when your energy levels tend to dip.[8][9]
Naps of all duration exert some form of benefit on your cognition.[8] However, it’s the rate at which these benefits emerge following a nap that you should be focusing on.
The benefits of a nap of around 10-20 minutes can be felt almost immediately and can last up to three hours.[8] On the other hand, you will likely feel an initial decline in your cognition immediately following a longer nap, though the benefits of your long rest may last for up to 24 hours.[8]
The optimal duration of a nap is around 20 minutes, which can boost your mood, alertness, and memory without causing sleep inertia or affecting your nighttime sleep.[8]
Though if you need more time to recharge, you can nap for up to 90 minutes, a full sleep cycle that can enhance your creativity and problem-solving skills.[10]
Ultimately, you should avoid napping longer than that or later in the day, as this can disrupt your sleep pattern and make you feel worse.
What’s the Bottom Line?
Sleep is essential for your brain health and overall well-being. Sleeping enough at night can help you maintain your cognitive abilities and prevent or delay the onset of neurodegenerative diseases.
However, if you struggle to get the recommended 7-8 hours of sleep per night, napping may be a valuable strategy to supplement your sleep and protect your brain from aging.
Remember to nap smartly and sparingly, and don’t use it as a substitute for good nighttime sleep hygiene.
You should consult your doctor if you have trouble sleeping or napping or experience excessive daytime sleepiness or fatigue. It’s important to rule out underlying medical conditions or sleep disorders that may affect your sleep and brain health.
References:
- Hirshkowitz, M., Whiton, K., Albert, S. M., Alessi, C. A., Bruni, O., DonCarlos, L. L., Hazen, N., Herman, J. B., Katz, E. S., Kheirandish-Gozal, L., Neubauer, D., O’Donnell, A., Ohayon, M. M., Peever, J. H., Rawding, R., Sachdeva, R., Setters, B., Vitiello, M. V., Ware, J. S., & Hillard, P. J. A. (2015). National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep Health, 1(1), 40–43. https://doi.org/10.1016/j.sleh.2014.12.010
- Paz, V., Dashti, H. S., & Garfield, V. (2023). Is there an association between daytime napping, cognitive function, and brain volume? A Mendelian randomization study in the UK Biobank. Sleep Health. https://doi.org/10.1016/j.sleh.2023.05.002
- Lee, J. D., McGue, M., Iacono, W. G., Michael, A. J., & Chabris, C. F. (2019). The causal influence of brain size on human intelligence: Evidence from within-family phenotypic associations and GWAS modeling. Intelligence, 75, 48–58. https://doi.org/10.1016/j.intell.2019.01.011
- Narayanan, S., Nakamura, K., Fonov, V. S., Maranzano, J., Caramanos, Z., Giacomini, P. S., Collins, D. L., & Arnold, D. L. (2020). Brain volume loss in individuals over time: Source of variance and limits of detectability. NeuroImage, 214, 116737. https://doi.org/10.1016/j.neuroimage.2020.116737
- Altena, E., Vrenken, H., Van Der Werf, Y. D., Van Den Heuvel, O. A., & Van Someren, E. J. (2010). Reduced Orbitofrontal and Parietal Gray Matter in Chronic Insomnia: A Voxel-Based Morphometric Study. Biological Psychiatry, 67(2), 182–185. https://doi.org/10.1016/j.biopsych.2009.08.003
- Anderson, E. L., Richmond, R. C., Jones, S. E., Hemani, G., Wade, K. H., Dashti, H. S., Lane, J. M., Wang, H., Saxena, R., Brumpton, B. M., Korologou-Linden, R., Nielsen, J. B., Åsvold, B. O., Abecasis, G. R., Coulthard, E., Kyle, S. D., Beaumont, R. N., Tyrrell, J., Frayling, T. M., . . . Smith, G. D. (2020). Is disrupted sleep a risk factor for Alzheimer’s disease? Evidence from a two-sample Mendelian randomization analysis. International Journal of Epidemiology, 50(3), 817–828. https://doi.org/10.1093/ije/dyaa183
- Cognitive Health and Older Adults. (n.d.). National Institute on Aging. https://www.nia.nih.gov/health/cognitive-health-and-older-adults
- Lovato, N., & Lack, L. (2010). The effects of napping on cognitive functioning. Progress in Brain Research, 155–166. https://doi.org/10.1016/b978-0-444-53702-7.00009-9
- Lastella, M., Halson, S. L., Vitale, J. A., Memon, A. R., & Vincent, G. E. (2021). To Nap or Not to Nap? A Systematic Review Evaluating Napping Behavior in Athletes and the Impact on Various Measures of Athletic Performance. Nature and Science of Sleep, Volume 13, 841–862. https://doi.org/10.2147/nss.s315556
- Patel, A. K. (2022, September 7). Physiology, Sleep Stages. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK526132/
