Getting roughly 7 hours of sleep each night and keeping a regular schedule

No cost involved. You simply need to set aside time for sleep — most people achieve this by cutting back on phone usage. The real challenge is maintaining consistent bedtime and wake-up times.

A pooled analysis of 16 longitudinal studies — which simply recorded data without grouping participants — included 1.38 million people and 113,000 deaths. People who slept less than 7 hours had a 12% higher mortality risk (RR 1.12), while those who slept more had a 30% higher risk (RR 1.30). Another pooled study that grouped participants by sleep duration found the lowest risk among those getting exactly 7 hours of sleep. For every hour slept under 7 hours, risk rose by 6% (RR 1.06); for every hour over 7 hours, risk rose by 13% (RR 1.13). Data from the UK Biobank, which tracked over 61,000 participants using wrist-worn monitors, also showed that when people were divided into 5 groups based on sleep regularity, the four groups with more consistent schedules had a 20–48% lower mortality risk than the least regular group. This confirms that sleep regularity is a stronger predictor of death risk than total sleep duration. A further UK Biobank study that tracked sleep timing for 51,562 participants found 3,853 new cases of cardiovascular disease over the study period. Social jetlag — the difference between average weekday and weekend bedtime — also plays a role: people with a social jetlag of 2 hours or more had a 30% higher risk of cardiovascular disease (HR 1.30, 95% CI 1.11–1.54). This link remained evident even among people getting a normal amount of sleep.

Cappuccio FP 等 (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 等 (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 等 (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

The main issues to address are getting too little sleep and having an irregular schedule; there is no need to deliberately cut back on total sleep time. The higher risk seen in people who sleep more is likely due to reverse causation: depression, chronic illnesses, and sleep apnea all tend to lead to longer sleep duration. Currently, only two longitudinal studies support the link between sleep regularity and lower mortality risk; both simply recorded data without grouping participants, so this evidence is classified as grade B on its own. For guidance on how to catch up on sleep after staying up late, see Section 39 of this chapter.