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How to Reset Your Sleep Clock

Moving our clocks forward this past weekend changed our bodies’ principal cue (light) for keeping time with our circadian rhythm. This usually causes us to be temporarily jet-lagged, or out of sync with our 24-hour wake/sleep schedule, making a lot of us feel a little off our game. Or more than that: Sleep deprivation is miserable. A poor night’s sleep is the ultimate mood killer, and over time those bad moods add up. People who regularly get less than seven hours of sleep at night are far more likely to develop depression or severe anxiety.

And did you know that modest reductions in sleep quality, even without a decrease in sleep quantity, tend to make us feel lonely? More than that, poor sleep quality leads us to act in ways that increase our isolation, not reduce it. Sleep-deprived people are more likely to avoid contact and are less inclined to engage with other people. Worse still, sleep-deprived folks tend to be judged as socially unattractive by others. And as if that isn’t enough, the effect is contagious: Well-rested people feel lonelier after even a one-minute encounter with a sleep-deprived person.
The good news is that we can use this disruption to reset our sleep clocks, which will soothe the anxiety that might have emerged this week.

How to Reset your Circadian Rhythm

Our sleep is primarily governed by a “biological clock” in the center of our brain called the suprachiasmatic nucleus. It sits just above the place where our optical nerves cross. This biological clock keeps time thanks to the light pulsing through the optical nerves below it. Unthwarted by modern life, the sun is a reliable winding mechanism: Every day since the dawn of the earth, the sun has risen and set in a 24-hour cycle.
As the sun sets, the suprachiasmatic nucleus detects the darkening world, which triggers the release of melatonin, the chemical messenger that commands the body to prepare for sleep. We feel sleepy and our body gets ready to fall asleep when melatonin starts to build up in our system, a few hours after dark.
When we expose ourselves to artificial light after sunset, though, our biological clock loses its primary winding mechanism. These days, light doesn’t stop pulsing through the suprachiasmatic nucleus until we turn off our bedside lamp and close our eyes—and even then, if there is still even a tiny source of light in our room, it might not. When we can’t fall asleep, often it’s because we don’t have enough melatonin built up in our system.
For that reason, looking at a phone, iPad, or computer is about the worst thing we can do before bed. One study found that reading on an iPad suppressed melatonin release by over 50 percent, compared to reading a paper book at night. The blue light emitted by our devices can delay the rise of melatonin by three hours, causing us to lose significant amounts of REM sleep—the type of sleep that is important for dreaming and that, when limited, most affects our moods.
You might be surprised to hear that even the tiny string lights that many college students string up around their dorm rooms can keep you from falling asleep. “Even a hint of dim light—8 to 10 lux—has been shown to delay the release of nighttime melatonin in humans,” writes UC Berkeley neuroscientist Matthew Walker in his book, Why We Sleep. “The feeblest of bedside lamps pumps out twice as much: anywhere from 20 to 80 lux.”
So, the first step is to turn the brightness on your screens way down at night, and to crank the “night shift” display settings to “most warm.” Unfortunately, according to some recent research, this won’t be enough to prevent light-induced melatonin suppression. So how can we best give ourselves the darkness we need to prepare for sleep?
  • Wearing dorky orange wrap-around glasses for an hour or two before bedtime tricks our biological clocks into thinking it is dark. This means that the suprachiasmatic nucleus will trigger the release of melatonin as though it were dark out.
  • We can also reset our biological clocks using light in the morning rather than darkness at night; bright light exposure for at least six and a half hours during the day can eliminate the hindering effects of artificial light exposure at night. On days when we aren’t able to expose ourselves to bright sunlight for this long, 20-30 minutes in front of a lightbox early in the morning can increase evening melatonin levels by 81 percent.
  • Although light is the primary way that our biological clock keeps time, our habits also influence our circadian rhythm. This is why so many of the best “healthy sleep guides,” like this one from the National Sleep Foundation, emphasize going to bed and waking up at the same time, as well as establishing a good bedtime routine.

So now is a great time for us all to establish — or reinforce — our bedtime routines. What do you do to wind-down at the end of the day and get yourself ready for deep sleep?


  1. MarkM3 says:

    Good article. In addition, there’s another factor you rarely hear about: meal timing.

    Here’s an excerpt from a Web article (I would’ve included a link, but I figured doing so would probably send this post straight into moderation):

    In his new book the Circadian Code, Satchin Panda, a professor at the Salk Institute and an expert on circadian rhythms research, argues that eating between an eight- to ten-hour window can help improve people’s metabolic health.

    But, this is far from what most people actually do. A typical person, according to Panda, eats within a 15-hour window.

    The idea behind this approach, also known as time-restricted feeding, is that our body’s metabolism follows a natural daily rhythm. (This has also been shown to burn fat and increase metabolism).

    Different hormones, enzymes, and bacteria seem to be optimized for
    the morning and afternoon. Just like jet-lag can mess with your body’s
    natural circadian rhythm and affect your energy levels and your health,
    so can eating at the wrong times of day, Panda argues.

    Anyway, this is a fascinating topic—and there are many articles on the Web about it.

      • MarkM3 says:

        Great. It was the first time I’d heard of the book. If you learn any more interesting insights, please share them here on your site. 🙂

        I personally have noticed that I feel different when I eat my first meal of the day within a couple hours of waking up than when I eat it, say, 6 hours later. One theory is that your first meal of the day tells your body, “OK, it’s morning!” I suspect there’s some truth to that.

        I’ve also found that I generally sleep better when I finish my last meal at least 3 hours before going to bed.

        With all the interesting research out there, hopefully it will become clearer and clearer how to live in sync with our circadian rhythms.

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