Tired of feeling groggy in the morning, barely stifling the urge to hit the snooze button? The fix could be as simple as a few nights under the stars, a small new study suggests.
The results pretty convincingly show a person’s internal clock could be reset in a matter of days, according to the report published in Current Biology.
The artificial glow from our smart phones, computers and TVs have thrown our internal clocks out of whack, causing us to stay up two hours later than we were biologically wired to, said study co-author Kenneth Wright, a professor of integrative physiology and director of the Sleep and Chronobiology Laboratory at the University of Colorado, Boulder. “This leaves us groggy in the morning at a time when we need to be alert for jobs and school."
In an earlier study, Wright and his colleagues showed that a week-long camping trip during the summer reset people’s biological clocks so that they fell asleep and woke two hours earlier than they normally did. As further evidence of a real change, the researchers documented a shift in the timing of the spike in melatonin, a hormone that starts to rise a couple of hours prior to sleep.
For the new study, the researchers ran two experiments: a week-long winter camping trip and a weekend summer trip.
In the winter study, Wright and his colleagues asked 4 men and one woman, whose average age was 30, to go about their normal schedules for a week, after which melatonin levels were monitored in the lab. The five volunteers were then taken on a weeklong backcountry camping trip in the Rocky Mountains. Over the course of the trip, bedtimes got earlier and earlier till the volunteers were falling asleep 2.5 hours earlier than they had at home. Melatonin measurements in the lab reflected the same shift.
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Even a cloudy day can help
What changed people sleep schedules?
The exposure to hours of sunlight, says Wright. People don’t realize how much difference there is between the level of light they encounter at work or school and what they are exposed to outdoors, he explains.
“Even on a cloudy day there is much more light outside than inside,” Wright says. “On a bright blue sunny day, you’re seeing 100,000-plus Lux. On a cloudy day it’s about 10,000 Lux. Indoors it’s normally about 200 Lux.”
One Lux is the illumination produced by a candle that is three feet away.
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Wright wondered how quickly people’s clocks could be reset. So as a second experiment, he rounded up 14 volunteers, 7 men and 7 women who average age was 28. At the beginning of the study, melatonin levels were measured for all the volunteers. Then half of them were sent on a weekend camping trip, while the others stayed home and kept to their normal schedules.
While the campers didn’t drop off any earlier than was normal for them, the stay-at-homes went to bed later than they did during the week.
Melatonin shift
While numerous explanations could be proffered for why that might happen — not much to do in a dark tent, for example — melatonin measurements made on all the volunteers after the campers came home showed that the time outdoors had had a significant effect.
The melatonin shift after a weekend camping was about 69 percent of what the researchers saw in those who went camping for a week. That shift, Wright says, would make it a lot easier for people to go to bed and rise earlier once they got home.
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Circadian clock expert Samer Hattar, was impressed at how quickly people’s internal clocks reset.
“With natural sunlight you get a big bang for your buck,” says Hattar, chief and senior investigator at the National Institute of Mental Health.
While you have to be cautious extrapolating from such small studies, they do make one wonder whether people are genetically programmed to be morning larks or night owls, Hattar says.
“This study shows the clock can be shifted by two hours,” he adds. “We may find that morning and evening people are exposing themselves differently to light. It’s amazing to think that humans, as complex as they are, are so dependent on natural light.”