Regular sleep may matter more than long sleep

The National Sleep Foundation recommends 7 to 9 hours a night for adults, and 7 to 8 for adults over 65. Hours aren't the whole story, though. When you sleep matters too.

A 2024 study gave 60,977 UK Biobank participants a wrist sensor for a week and scored how much their sleep and wake times shifted from day to day. Over about 6 years, people in the four more regular groups had a 20 to 48% lower risk of death than the least regular fifth. Regularity predicted death better than sleep length did.

That's one observational study. People with irregular sleep often have other things going on, like shift work or poor health. The researchers adjusted for many of these, but they couldn't measure everything.

The simplest change is a fixed bedtime. Ageon counts a consistent night when you go to bed within 30 minutes of your usual bedtime, which is the middle value of your previous 14 nights. It needs at least 5 nights of sleep data before it starts counting. Bedtime is a simpler measure than the one the study used, which also tracked when you wake.

Find the one thing that most often pushes your bedtime late, and change that first.