On Monday morning, hundreds of millions of Americans were united by one thought: Boy, am I tired.
According to Facebook data from 2014, Americans are significantly sleepier on the Monday after Daylight Saving Time starts — or, at least, we spend more time complaining about being sleepy on social media. So either way, the zeitgeist is one of general crankiness.
But what’s up with that? Once we stop having parent-mandated bedtimes, most of us vary the amount of sleep we get from night to night. You wouldn’t think that shifting things around by an hour would make all that much difference.
Well, you’re wrong. And how! One study found that it takes up to a week for your body’s circadian rhythm — the light-based cycle that tells us when our bodies need to sleep, regardless of our conscious thoughts on the subject — to adjust to even the single-hour shift.
We’re all too sleepy for a huge song and dance on circadian rhythms, but here’s the big takeaway: Your body has to put your brain to sleep at some point, and it operates on a roughly 24-hour cycle. When it’s sleepy-time, hormones such as melatonin ramp up to trigger drowsiness. Your body is generally set to release more melatonin when it’s dark out — which is why researchers say we should be careful about how much light from phones and computers we expose ourselves to around bedtime. And when it gets light, your body primes you to wake up by dialing down that chemical cocktail. That cycle, while roughly light-based, still adjusts to fit your schedule — so even though you might have gotten eight hours of sleep last night, your body is still pretty confused.
“Remember, we have clocks in every organ in our body,” Robert Thomas, the director of a sleep medicine fellowship at Harvard’s Beth Israel Deaconess Medical Center, told The New York Times. “You’re not just moving sleep — you’re moving your entire body. It’s like a giant ocean liner. A big ocean liner slowly chugging away. You can’t just jerk it around.”
Tell me about it, man.
To make matters worse, when we set our clocks forward we end up waking up to darker mornings. Today’s 7 a.m. was yesterday’s 6 a.m., and the sun was just not all that ready to face the day yet. In addition to the sleep schedule change itself, your body is also reacting to the fact that there was less light to prime that chemical wake-up process today than there was yesterday. A recent study of college students suggested that the spring-forward process really is more disruptive to the sleep-wake cycle than falling back.
“Light doesn’t do the same things to the body in the morning and the evening,” Till Roenneberg, a chronobiologist at Ludwig-Maximilians University, told National Geographic. Roenneberg actually believes that our sleep clock might not ever adjust to our self-imposed DST shifts — which is kind of a terrifying thought. “More light in the morning would advance the body clock, and that would be good. But more light in the evening would even further delay the body clock,” Roenneberg said.
And even in the fall, studies have found, folks rarely take advantage of their “extra” hour of sleep.
The best way to adjust to the change is to get plenty of sleep and expose yourself to as much light as possible first thing in the morning — and as little as possible starting a couple of hours before bed. And don’t forget to take advantage of those sunny evenings when you get out of work: According to that Facebook study we mentioned before, folks are actually in a better mood in general when DST starts — presumably because we get to do fun, sunshine-y, springy things instead of emerging into the twilight when school and work end.
But for today, no one will judge you if you skip the walk in the park and take a nap instead.