How To Schedule Your Day & Night Around Your Circadian Peaks

Just like the watch on your wrist, your body itself is a reliable timepiece. This internal clock—or circadian rhythm—keeps vital biological processes like sleep and digestion running on track. 

Your circadian rhythm runs on a roughly 24-hour cycle (the term circadian comes from the Latin circa, "around," and diem, "day") and is primarily affected by light and darkness. However, factors like stress, temperature, and physical activity can also cause your inner clock to jump ahead or turn back—leaving you tired, sluggish, and mentally foggy, similar to how you might feel after changing time zones. When your clock is in sync with your surroundings, you're more likely to be energized during the day, tired at night, and able to fall into a deep sleep. 

While everybody's rhythm (and ability to cater to it) is a bit different, there are a few habits that can help most of us reinforce this tremendous timekeeper within. Here's what the latest available science says about the ideal times to eat, exercise, work, and sleep for your circadian clock. 

Get some light first thing: Since the circadian clock is primarily dictated by light, starting the day off outside (or at least, in front of a window) can help get yours off to a strong start. By getting sunlight first thing in the morning, you are "entraining" your rhythm to your environment, sending a strong message to your body that another day has begun and it's time to wake up. Research shows that just five minutes of sunlight is enough to impact the circadian clock1, so get into the routine of taking a short walk around your neighborhood (even if it's cloudy out!) upon waking for optimal mood and energy in the morning. 

Schedule mentally demanding tasks during your circadian peak: You'll want to schedule your most cognitively challenging tasks for the hours when your brain is the most alert. And according to circadian researcher and author of The Circadian Code, Satchin Panda Ph.D., for most people, that's between 10 a.m. and 3 p.m. As Panda writes in his book, though everyone's clock is a bit different, the vast majority of us will get our best thinking done within this window and should be planning our work, studying, etc., accordingly.

Be gentle on yourself: Your energy will likely dwindle in the early afternoon as you approach to end of your peak hours. This is just the way your clock is wired—and there's no point in fighting it. Instead, work with your rhythm and reserve the hours after 3 p.m. for your less urgent tasks. If you struggle to even get those done, try taking a walk outside for a jolt of energizing light and a quick mood boost3. Getting the body moving, especially right after your midday meal, can also help combat drowsiness and blood sugar spikes.

Eat dinner at least three hours before bed: Your circadian clock ideally lines up with the sun, making the sunset a visual cue that your body also wants to start settling down for the night. The name of the game during the nighttime hours is to avoid stimulating activities that will interrupt your body's wind-down processes; eating included! Aim to wrap up dinner at least three hours before you plan to go to bed to support a healthy circadian rhythm (and deeper sleep, by extension). 

Resist the temptation to work or look at screens: As Panda writes in The Circadian Code, "There's no way you can be productive and tired at the same time." While working late into the night may seem like a necessary evil during busy time periods, circadian science shows that you're better off just prioritizing sleep and waking up early to do it the next morning, when you'll be more attentive and productive. Working late can not only trigger the release of cortisol and other stress hormones that disrupt sleep, but the blue light emitted by phone and laptop screens can trick your brain into thinking it's earlier in the day than it is, further delaying sleep. Finding tech-free nightly activities is especially important for night owls, who are naturally inclined to push back their bedtimes.