A day-by-day plan to wake up earlier for a morning run or workout, moving your bedtime with it so you keep your sleep. Runs in your browser; nothing is saved or sent.
What this does: builds a day-by-day plan that moves your wake time earlier in small steps, for example so you can fit in a run or a workout before work. We move your lights-out time earlier by the same amount, so you keep the same hours of sleep, and each day shows when to have your last caffeine and when to start dimming the lights. It’s for adults on a regular daytime schedule who want to wake up earlier. Enter when you wake up now, when you want to wake up, the hours of sleep you need and a pace.
Body clock (circadian rhythm): the roughly 24-hour internal timer that sets when you feel sleepy and when you feel alert. Light is what mostly keeps it on time.
Shifting your body clock earlier: moving that whole rhythm earlier, so sleepiness arrives earlier in the evening and alertness earlier in the morning.
Lights-out time: when you’re in bed with the lights off, ready to sleep.
Step: how many minutes earlier we move your wake time, and your bedtime with it, at a time.
Most adults 18 to 60 need 7 or more hours a night; adults 65 and older, 7 to 8.
Choose Faster only if you get bright light every morning, outdoors or from a light box (a very bright lamp made for this). Night owls often do better with Gentle.
How it works
Your body clock runs on a cycle of roughly 24 hours, and for most people it runs slightly longer than 24 hours, so it tends to drift later each day. That is why shifting it earlier is harder than shifting it later, and why we move in small steps (Eastman & Burgess, 2009).
In a lab study of 28 healthy young adults, moving the sleep schedule 1 hour earlier each day for 3 days moved the body clock about 0.6 hours in ordinary indoor light, and about 1.5 to 2.1 hours when they also got bright light in the first hours after waking (Burgess et al., 2003). In a second study, moving sleep 2 hours earlier a day did no better than 1 hour a day, and by the third day the 2-hour group found it harder to fall asleep (Eastman et al., 2005). The researchers advise moving sleep no more than 1 hour earlier a day, and even less for night owls (Eastman & Burgess, 2009). Natural light matters too: after a week of only natural light on a camping trip, body clocks ran about 2 hours earlier in 8 adults (Wright et al., 2013).
How we build your plan. We use smaller steps than those studies did: Steady moves your wake time 15 minutes earlier each day, Gentle 15 minutes every 2 days, and Faster 30 minutes a day for people who get bright light every morning. Your lights-out time moves by the same amount, so your sleep stays the same length every night; adults need 7 or more hours on a regular basis (Watson et al., 2015; CDC). Your last caffeine is 6 hours before lights out, and dimming the lights starts 2 hours before. A move of more than 4 hours is easier in stages, so each plan covers up to 4 hours.
Tips that help your body clock move
Light in the morning. Light is the main signal that sets your body clock, and light that arrives after the low point of your body’s daily temperature cycle, a few hours before you usually wake, moves the clock earlier (Khalsa et al., 2003; Eastman & Burgess, 2009). In studies, bright light in the first hours after waking helped the clock move earlier (Burgess et al., 2003). Get outside soon after your alarm: outdoor daylight is roughly 10,000 to 100,000 lux (a measure of brightness), far brighter than indoor lighting, even on a cloudy day (Eastman & Burgess, 2009). A 20 to 30 minute walk or run outside early in the day is an easy way to do it. If it’s still dark when you wake, the studies used a bright light box (about 5,000 lux) in the first hours after waking.
Light in the evening. As your bedtime moves earlier, dim the lights in the last hour or two before bed. Bright light late in the evening tells your body clock it’s still daytime and can push it later, and even ordinary room light has an effect (NHLBI; Gooley et al., 2011; Zeitzer et al., 2000).
The same wake time every day, weekends included. A later weekend wake time can move your clock back the wrong way. The National Heart, Lung, and Blood Institute advises keeping weekday and weekend sleep schedules within about an hour of each other (NHLBI). In one study, adults on their normal routine went to sleep and woke about 1.1 hours later on weekends (Stothard et al., 2017), and in 61 college students, the most irregular sleepers had body clocks running about 2½ hours later than the most regular sleepers (Phillips et al., 2017).
Caffeine. Caffeine’s effects can last up to 8 hours (NHLBI). In one study, a large dose 6 hours before bed still cut sleep time (Drake et al., 2013), and in another, caffeine 3 hours before bed shifted the body clock about 40 minutes later (Burke et al., 2015). That is why your last-caffeine time moves earlier along with your bedtime.
Morning workouts. A morning workout may help. In a lab study of healthy adults, an hour of moderate treadmill exercise at 7 a.m. moved the body clock earlier, a smaller effect than bright light, while exercise between 7 and 10 p.m. moved it later (Youngstedt et al., 2019). Try to finish hard evening workouts early, and avoid intense exercise in the hour before bed (NHLBI). A morning run outside gets you daylight and exercise together.
Everyone’s clock is different. People vary in how fast their body clock moves, and night owls often need smaller steps and more morning light (Eastman & Burgess, 2009).
Once you’re there. Keep the target wake time and the morning light going. A steady routine is what keeps the new time in place.
Who should talk to a doctor first
Trouble sleeping three or more nights a week for more than three months is called chronic insomnia, and a health care provider can help with it (NHLBI; CDC). Body clock sleep conditions, such as not being able to fall asleep until very late no matter what you try, are diagnosed and treated by sleep doctors (Auger et al., 2015). This plan is built for adults on a regular daytime schedule, not for night or rotating shift work.
Sources
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Watson NF, Badr MS, Belenky G, et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. J Clin Sleep Med. 2015;11(6):591–592. Source
Centers for Disease Control and Prevention. About sleep. Source
National Heart, Lung, and Blood Institute. Healthy sleep habits. Source
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Stothard ER, McHill AW, Depner CM, et al. Circadian entrainment to the natural light-dark cycle across seasons and the weekend. Curr Biol. 2017;27(4):508–513. Source
Gooley JJ, Chamberlain K, Smith KA, et al. Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humans. J Clin Endocrinol Metab. 2011;96(3):E463–E472. Source
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Burke TM, Markwald RR, McHill AW, et al. Effects of caffeine on the human circadian clock in vivo and in vitro. Sci Transl Med. 2015;7(305):305ra146. Source
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Phillips AJK, Clerx WM, O’Brien CS, et al. Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timing. Sci Rep. 2017;7:3216. Source
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General information for healthy adults on a regular daytime schedule, not medical advice. If you have a sleep or other medical condition, or work nights or rotating shifts, talk to a doctor or sleep specialist before changing your sleep schedule.