This post by sleep scientist Dr. Jason C. Ong is part of our Sleep Health course. You can experience the full 14-day course with a subscription to the Headspace app.
People are often surprised when I tell them this, but if you want to sleep well on a regular basis, the single most important thing you can do is to have a consistent wake-up time. This is because your circadian rhythm, also known as your body clock, is guided by your wake-up time rather than your bedtime. The circadian rhythm doesn’t respond instantly, it adjusts gradually over several days, and this adjustment is exactly what’s happening when we experience jet lag. We find we’re tired at awkward times, and we can’t sleep when we get into bed. Our circadian rhythm is still on the schedule of our old time zone, so it’s lagging behind by something like an hour or more a day. An irregular wake-up time, whether that’s on the weekend, or after a bad night’s sleep, confuses your biological clock in just the same way — in fact, sleep doctors sometimes call this “social jet lag.” Obviously then, the best way to ensure that you’re sleepy at the same time each day is to wake up and get out of bed at the same time every day, even on the weekends. This is actually the opposite of what most people assume is the best thing for their sleep. They go to bed at the same time each day and vary the wake-up time based on how they slept during the night. Unfortunately, this works against the way the body regulates sleep, and that can lead to frustration when you get into bed. So ideally, try to maintain a wake-up time within a consistent 15-minute window every day. Even if you’ve slept badly. And even if you’ve been out the night before. And before you know it, you’ll have your body clock working like, well, clockwork again.