Experts Break Down 19-Year Study Results

A 19-year study has identified a link between specific daytime napping patterns and an increased risk of all-cause mortality among older adults. The research suggests that while occasional naps may be restorative, excessive or poorly timed daytime sleep can serve as a trackable warning sign for underlying health decline.

The findings, published in JAMA Network Open on April 20, 2026, were the result of a collaboration between investigators from Mass General Brigham and Rush University Medical Center. Researchers followed 1,338 community-dwelling adults in Illinois who were 56 or older, with a mean age of 81.4 years. The cohort was 93.3% White and 76% female.

To ensure accuracy, the study moved away from self-reported data, which can be unreliable due to memory lapses. Instead, participants wore actigraphy devices—wrist activity monitors—for up to 14 days to objectively map nap duration, frequency, timing, and day-to-day variability.

The Risks of Duration, Frequency, and Timing

The researchers defined daytime napping as sleep episodes occurring between 9 a.m. And 7 p.m. The data revealed that the risk of mortality increased alongside the amount and frequency of daytime sleep.

• Each additional hour of daytime napping per day was associated with a 13% higher mortality risk.
• Each additional nap taken per day was associated with an approximately 7% higher mortality risk.
• Participants who napped in the morning showed a 30% higher mortality risk compared to those who napped in the afternoon.

Interestingly, the study found that irregular napping patterns—variability in how long or how often a person napped from day to day—were not associated with an increased risk of mortality.

Correlation vs. Causation

Experts emphasize that these results indicate a correlation rather than a direct causal link. This means that the act of napping itself may not be causing death, but rather that the need for excessive daytime sleep is a symptom of other systemic issues.

Excessive napping is likely indicating underlying disease, chronic conditions, sleep disturbances, or circadian dysregulation

Chenlu Gao, PhD, investigator at Mass General Brigham and Rush University Medical Center

Researchers speculate that these napping habits may be manifestations of cardiovascular changes, neurological decline, or chronic inflammation. The study noted that morning napping, particularly immediately after waking, holds a particular risk that may reflect a struggle to maintain normal alertness cycles.

Clinical Implications and Sleep Guidance

Because these patterns can appear before a formal diagnosis is made, medical professionals suggest that changes in sleep habits should be treated as clinical data. Dr. Kelley, an expert cited in the research breakdown, noted that physicians should incorporate questions about napping patterns into routine physicals to help identify underlying chronic conditions.

We are looking for changes in the pattern of napping rather than napping overall. Immediately napping after waking up in the morning holds a particular risk and should be investigated

Dr. Kelley

While the study highlights the risks of excessive napping, health experts maintain that the primary focus should remain on the quality of nighttime rest. Koh, a health expert, stated that adequate sleep duration is important and recommended that adults target seven to nine hours of good quality sleep each night.

Medical providers suggest that individuals who experience a sudden shift in their energy levels or a new, frequent need for morning sleep should visit a physician for screening to rule out cardiovascular strain or other biological disruptions.