Sleep around seven hours a night on a regular schedule
Habitually short sleepers had about 10% higher mortality. Irregular schedules were also associated with higher risk: more regular sleepers had 20%–nearly 50% lower mortality than the least regular. Regularity predicted mortality better than duration.
What it takes
Free, but you must make time—often by replacing phone scrolling with sleep. Keeping bedtime and waking time steady takes effort.
What you may gain
A meta-analysis of 16 observational studies, with 1.38 million people and 113,000 deaths, found 12% higher mortality with short sleep (RR 1.12) and 30% higher mortality with long sleep (RR 1.30). Another analysis found the lowest risk at 7 hours: below that, each hour less was associated with 6% higher risk (RR 1.06); above it, each hour more with 13% higher risk (RR 1.13). Wrist-device records for about 61,000 UK Biobank participants placed people in five regularity groups. The four more regular groups had 20%–48% lower mortality than the least regular; regularity predicted mortality better than duration. Another UK Biobank study measured sleep timing in 51,562 people, of whom 3,853 developed cardiovascular disease. Social jet lag—the difference in sleep midpoint between workdays and weekends—of at least 2 hours was associated with 30% higher cardiovascular risk (HR 1.30, 95% CI 1.11–1.54), including among people with normal sleep duration.
Context & considerations
Address insufficient sleep and irregular timing; do not deliberately shorten needed sleep. Long sleepers' higher risk likely partly reflects reverse causation: depression, chronic illness and sleep apnea can increase time spent asleep. Regularity itself is supported here by two observational studies and would receive grade B separately. See catching up after a late night.
Research & references
Cappuccio FP et al. (2010). Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep. https://doi.org/10.1093/sleep/33.5.585 ; Yin J et al. (2017). Relationship of Sleep Duration With All-Cause Mortality and Cardiovascular Events: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies. JAHA. https://doi.org/10.1161/JAHA.117.005947 ; Windred DP et al. (2024). Sleep regularity is a stronger predictor of mortality risk than sleep duration: A prospective cohort study. Sleep. https://doi.org/10.1093/sleep/zsad253 ; Kumar N, Krishnamurthy S (2026). Social jet lag is associated with incident cardiovascular disease independent of sleep duration and cardiac genetic risk. Journal of Internal Medicine. https://doi.org/10.1111/joim.70133