Getting about 7 hours of sleep each night with a consistent schedule

Cost: No cost involved. You simply need to allocate time for sleep — most people achieve this by cutting back on phone usage. The real challenge is maintaining a fixed bedtime and wake‑time.
In plain terms: People who regularly get less than 7 hours of sleep have roughly a 10% higher chance of dying over time. The more irregular their schedule, the greater the risk. Those with the most regular sleep patterns enjoy a 20%–50% lower mortality risk compared to those with the least regular patterns. In other words, how consistent your sleep schedule is matters more than the total number of hours you sleep.
Benefit: A pooled analysis of 16 longitudinal studies — involving 1.38 million participants and 113 000 deaths — shows that short sleepers face a 12% higher risk of death (RR 1.12), while long sleepers face a 30% higher risk (RR 1.30). When sleep duration is grouped into categories, the 7‑hour bracket shows the lowest risk; each additional hour beyond 7 raises risk by about 13% (RR 1.13), and each hour less than 7 raises it by roughly 6% (RR 1.06). In the UK Biobank, wrist‑watch data from ~61 000 participants were used to rank them into five groups based on schedule regularity; the four more regular groups had a 20%–48% lower mortality risk than the least regular group. Another UK Biobank study tracked 51 562 individuals for new cardiovascular events; those with a social jet‑lag of 2 hours or more faced a 30% higher risk (HR 1.30, 95% CI 1.11–1.54), and this link persisted even among people getting a normal amount of sleep.
Evidence grade: A
Sources: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
Notes: The main issues to address are insufficient sleep and irregular schedules; there’s no need to deliberately shorten sleep time. The elevated risk seen in long sleepers is likely reversed causality — depression, chronic illness, and sleep apnea tend to cause longer sleep durations. Currently, only two longitudinal studies support the benefit of a regular schedule; both are observational and ungrouped, so they constitute B‑grade evidence on their own. For ways to recover after staying up late, see Section 38 (recovering sleep after a late night). 〔113000〕〔61000〕〔51562〕〔3853〕