Keep naps to half an hour and no more than an hour; if you can only get through the day with a 1- or 2-hour sleep, find out why

Cost

Free. Set an alarm before you lie down; it takes almost no willpower.

What you get

An umbrella review pooled 16 meta-analyses covering 244 health outcomes. An umbrella review means pooling already pooled studies once more. Conclusion: people who napped less than 60 minutes had no higher overall mortality or chronic disease risk, and the improvement in mental performance was also the most marked (SMD 0.69, 95% CI 0.37–1.00, the plausible range). Short naps of 20 to 30 minutes gave the biggest improvement in athletic performance (SMD 0.99, 0.67–1.31). People who napped more than 60 minutes had about 30% higher risk of coronary heart disease, and about 20% higher risk of diabetes and obesity. Another study had 1338 older adults aged 56 and over wear a wrist watch to measure naps, instead of relying on questionnaires. They were followed for up to 19 years, during which 926 died. Each extra 1 hour of napping was linked to about 13% higher risk of death (HR 1.13, 95% CI 1.04–1.23). One more nap a day was about 7% higher (HR 1.07, 1.02–1.13). People who napped in the morning had about 30% higher risk than those who napped in the early afternoon (HR 1.30, 1.03–1.64).

Notes

Disputed. Both studies above are observational, not assigning groups. People who nap long were more likely to have sleep apnea, anemia, an underactive thyroid, depression or other chronic illness to begin with. So how much of “people who sleep long die more” is caused by napping itself is hard to say. A causal analysis using genes (Mendelian randomization, 453,000 (45.3万) people plus 541,000 (54.1万)) supports only one thing: the more often people nap, the slightly higher their blood pressure and waist size. It found no causal effect of napping on coronary heart disease or diabetes. So don't treat “napping less” as a way to lower mortality. The “find out why” half is the authors' suggestion and is grade C: if you are so sleepy in the daytime that you must sleep long, first look at your sleep at night. If you snore or stop breathing in your sleep, get checked for sleep apnea, then have a blood count and thyroid test. For how to refresh yourself with a short nap, see §3.11 (take a 10-minute nap when you're drowsy in the afternoon). For how long to sleep at night, see §2.13 (sleep about 7 hours a night).

Evidence grade

B : Supported by research but without a precise number, or based on small or single studies.

Sources

1. 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
2. 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
3. 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

Translated from the Chinese original. Original book, section 2, tip 37. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer