Keep naps under 30 minutes — no longer than an hour. If you need a full hour or more to feel functional, it’s time to get checked out.

It costs nothing. Just set an alarm before you nap; it requires almost no willpower at all.

One umbrella meta-analysis pooled data from 16 separate meta-analyses covering 244 health outcomes. The bottom line: people who nap fewer than 60 minutes experience no rise in overall mortality or chronic disease risk, and see the greatest gains in cognitive function (SMD 0.69, 95% CI 0.37–1.00 — a reliable range). Naps lasting 20–30 minutes produce the biggest improvements in physical performance (SMD 0.99, 95% CI 0.67–1.31). In contrast, naps exceeding 60 minutes raise coronary heart disease risk by roughly 30%, and diabetes and obesity risk by about 20%. Another study used wrist-worn monitors to track actual nap duration in 1,338 adults aged 56 and older, rather than relying on self-reported surveys. After up to 19 years of follow-up, 926 participants died. For every extra hour of napping, mortality risk rose by about 13% (HR 1.13, 95% CI 1.04–1.23). Each additional daily nap added roughly 7% to that risk (HR 1.07, 95% CI 1.02–1.13). Naps taken in the morning carried a roughly 30% higher risk compared to those taken earlier in the afternoon (HR 1.30, 95% CI 1.03–1.64).

Du P, Li J, Hua Z, 等 (2026). Multiple Health Outcomes of Daytime Napping: A Comprehensive Umbrella Review. Public Health Reviews. https://doi.org/10.3389/phrs.2026.1609013；Gao C, Cai R, Zheng X, 等 (2026). Objectively Measured Daytime Napping Patterns and All-Cause Mortality in Older Adults. JAMA Network Open. https://doi.org/10.1001/jamanetworkopen.2026.7938；Dashti HS 等 (2021). Genetic determinants of daytime napping and effects on cardiometabolic health. Nature Communications. https://doi.org/10.1038/s41467-020-20585-3

This topic remains controversial. Both of the major studies mentioned above merely recorded nap duration without stratifying participants by health status. People who habitually nap longer are more likely to suffer from sleep apnea, anemia, hypothyroidism, depression, or other chronic conditions; therefore it’s hard to isolate exactly how much of the observed mortality increase is directly attributable to napping itself. Mendelian randomization studies involving 453,000 and 541,000 participants respectively found only one consistent link: the more frequently someone naps, the slightly higher their blood pressure and waist circumference become. No causal effect on coronary heart disease or diabetes was identified. Consequently, “shortening naps” shouldn’t be promoted as a standalone strategy for lowering mortality. The recommendation to “get checked out” is an author‑suggested precaution; it falls under a lower‑grade evidence tier. If daytime fatigue forces you to nap for extended periods, first evaluate nighttime sleep quality — check for snoring or breathing pauses that might indicate sleep apnea — and then arrange routine blood tests and thyroid screening. For quick, effective energy boosts, see Section 3, Item 11 (a 10‑minute afternoon nap works best). Optimal nighttime sleep duration is discussed in Section 13 of this chapter (aim for 7 hours per night).