Napping behaviors predict mortality risk in middle-to-older aged adults

DARIEN, IL – A new study to be presented at the SLEEP 2025 annual meeting found that certain objectively measured daytime napping behaviors are associated with an increased risk of mortality for middle-to-older aged adults.

Results show that the median nap duration was 0.40 hours per day. Thirty-four percent of naps were taken between 9 a.m. and 11 a.m., 10% were taken between 11 a.m. and 1 p.m., 14% were taken between 1 p.m. and 3 p.m., 19% were taken between 3 p.m. and 5 p.m., and 22% were taken between 5 p.m. and 7 p.m. An analysis found that longer naps, greater variability in daytime nap duration, and higher percentages of naps around noon and in the early afternoon are associated with greater mortality risks.

“In evaluating the results of the sleep study, we were surprised by how common napping was among middle-to-older aged adults, how much their daytime sleep patterns varied across days, and when during the day they are sleeping,” said lead author Chenlu Gao, a postdoctoral research fellow at Massachusetts General Hospital in Boston. “People who slept longer during the day, had irregular daytime sleep patterns, or slept more around midday and early afternoon were at greater risk, even after accounting for health and lifestyle factors.”

The American Academy of Sleep Medicine encourages healthy adults to limit naps to no longer than 20-30 minutes in the early afternoon. While a brief “power” nap can improve daytime alertness and performance, naps of 30 minutes or longer may cause a person to feel groggy after waking up. This grogginess, or “sleep inertia,” can delay the short-term performance benefits of a nap. 

“Interestingly, the data that shows risks associated with napping around midday and early afternoon contradicts what we currently know about napping, so further research on that link could be warranted,” Gao added.

The study sample comprised 86,565 non-shiftworking participants in the UK Biobank with an average baseline age of 63 years; 57% were women. They were monitored by actigraphy for seven days, and daytime napping was defined as sleep between 9 a.m. and 7 p.m. Mortality data were obtained from national registries. There were 5,189 (6.0%) participants who died during a follow-up period of up to 11 years. Results were adjusted for potential confounders including demographics, body mass index, smoking, alcohol consumption, and nighttime sleep duration.

Gao noted that the results are important because they highlight the potential significance of considering daytime sleep behaviors in the risk stratification of mortality in adults. However, the study has some limitations. Because it relied on actigraphy, which detects movement but not brain activity, quiet wakefulness may have been misclassified as sleep. Additionally, defining daytime napping as sleep between 9 a.m. and 7 p.m. could have inadvertently included portions of participants’ primary sleep episodes, potentially affecting the accuracy of nap classification.

“Incorporating actigraphy-based daytime sleep assessments into clinical and public health practices may provide novel opportunities for early risk identification and personalized interventions to promote longevity,” Gao said.

This study was supported by the Alzheimer’s Association and AASM Foundation. The research abstract was published recently in an online supplement of the journal Sleep and will be presented Wednesday, June 11, during SLEEP 2025 in Seattle. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

###

Abstract Title: Objectively-Assessed Napping Behaviors Predict Mortality in Middle-to-Older Aged Adults
Abstract ID: 0350
Poster Presentation Date: Wednesday, June 11, 10-10:45 a.m. PDT, Board #067
Presenter: Chenlu Gao, postdoctoral research fellow at Massachusetts General Hospital

About the Associated Professional Sleep Societies, LLC

The APSS is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. The APSS organizes the SLEEP annual meeting each June (sleepmeeting.org).

About the American Academy of Sleep Medicine
Established in 1975, the AASM is a medical association that advances sleep care and enhances sleep health to improve lives. The AASM membership includes more than 9,500 physicians, scientists, and other health care professionals who help people who have sleep disorders. The AASM also accredits 2,300 sleep centers that are providing the highest quality of sleep care across the country (aasm.org).

About the Sleep Research Society 

The SRS is a professional membership society that advances sleep and circadian science. The SRS serves its members and the field of sleep and circadian research through training and education, and by providing forums for the collaboration and exchange of ideas. The SRS facilitates its goals through scientific meetings and trainee specific programming, and by advocating for federal sleep and circadian research funding. The SRS also publishes the peer-reviewed, scientific journals Sleep and Sleep Advances (sleepresearchsociety.org).