Wake up at the same time every day

Why your wake-up time matters

Your body runs on an internal clock, a roughly 24-hour rhythm that times sleepiness, alertness, hunger and body temperature. That clock takes its cues from when you see light, eat and get up. Researchers call the gap between your weekday and weekend sleep timing "social jet lag", and it is common among working adults. If you get up at 6:30 on weekdays and 9:30 on weekends, your clock shifts by three hours every Saturday, much like flying from New York to Los Angeles and back each week.

Bedtime matters too, but it is harder to control, since you can't fall asleep on command. Getting up at the same time is something you can do even after a rough night. That makes the wake time a sensible place to start.

How a steady morning helps

When you wake at a regular time, your body learns to expect it. In the hours before a usual wake time, body temperature tends to rise. Levels of cortisol, a hormone that helps you get going, climb as well.

Morning light adds to this. Light reaching your eyes after you wake tells your clock that the day has begun. That helps set when melatonin, the hormone linked to sleepiness, rises again in the evening. With a regular wake time, the light arrives at a similar hour each day, so evening sleepiness tends to arrive on schedule too.

What the research found

In a large UK study, researchers tracked the sleep of about 60,000 adults with wrist-worn activity monitors for a week. People with the most regular sleep patterns had a 20 to 48% lower risk of dying during follow-up than those with the least regular patterns. Regularity predicted risk of death better than sleep length did. A US study of nearly 2,000 middle-aged and older adults found a similar pattern for the heart. Those whose sleep length varied most from night to night had about twice the risk of heart attacks, strokes and related events over about five years.

In a smaller study of 61 Harvard students, irregular sleepers had body clocks running about 2.6 hours later and tended to earn lower grades. These are observational studies, so they show links and can't prove that regular timing caused the difference. People with irregular sleep may also differ in health, work or stress in ways researchers could not fully measure. Long trials that change only wake-up timing haven't been done yet, so any benefit you notice may be modest and take a few weeks.

Making it stick on weekends

Pick a wake time you can actually hold on Saturday and Sunday as well as on workdays. If your weekday alarm is 6:00 and you love a lie-in, a time like 6:30 every day may be easier to keep. You don't need to be exact to the minute: staying within about 30 minutes of your chosen time is a reasonable target. Put your alarm across the room so you have to stand up to switch it off, then open the curtains. You will hear yourself bargaining on the walk over, and that is fine.

After a late night, still get up at your usual time and take a nap of about 20 minutes in the early afternoon if you need it. If seven days feels like too much, start with weekdays, then work toward the same wake time, every day, once Monday mornings feel easier. Later, adding a steady bedtime is the natural next step. Over a few weeks, you become someone whose mornings start at the same hour, whatever day it is. If you regularly lie awake for long stretches, snore loudly or feel sleepy all day despite a steady schedule, see a doctor, since a fixed alarm won't fix insomnia or sleep apnea. What time could you realistically get up next Sunday?

References

• Windred, D. P., et al. (2024). Sleep regularity is a stronger predictor of mortality risk than sleep duration: A prospective cohort study. Sleep, 47(1), zsad253. doi.org/10.1093/sleep/zsad253
• Huang, T., et al. (2020). Sleep irregularity and risk of cardiovascular events: The Multi-Ethnic Study of Atherosclerosis. Journal of the American College of Cardiology, 75(9), 991-999. doi.org/10.1016/j.jacc.2019.12.054
• Phillips, A. J. K., et al. (2017). Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timing. Scientific Reports, 7, 3216. doi.org/10.1038/s41598-017-03171-4
• Wittmann, M., et al. (2006). Social jetlag: Misalignment of biological and social time. Chronobiology International, 23(1-2), 497-509. doi.org/10.1080/07420520500545979