Camping resets your internal clock, say researchers
Getting away from artificial light can recalibrate your sleep cycles so that they are more similar to those of our ancestors, researchers suggest.
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"It rises at night naturally, and falls during the day, suppressed by light," said Goel.Skip to next paragraph
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Melatonin also drops the body’s core temperature, making it easier to sleep. People often take melatonin pills to help them fall asleep, she said.
After the week’s study indoors, the Colorado subjects went camping in the Rockies. Instead of artificial lighting, they had only sunshine during the day and campfires at night. Wright estimates the light from the sun was four times as intense as what they experienced indoors. The nature of the light also changed during the day. Think of the bright white light of midday and the golden glow that often precedes sunset.
After their week of camping, researchers measured the subjects' melatonin levels again.
The researchers found that the onset of melatonin shifted two hours earlier, and the subjects’ actual sleep shifted more than an hour earlier. Their bodies were recalibrating themselves, Wright explained.
When they woke in the morning in their normal lives, the melatonin and the external time were in conflict. They were waking up, but the melatonin in their bodies was telling them they should still be asleep. That might account for their still feeling sleepy, Wright said.
When they were out in the outdoors, the melatonin levels and the sun cycle were more aligned--the levels went down as the sun rose and before they woke up. They were subject to more light -- sunlight -- for the majority of the day.
The relationship between light and sleep and how much sleep a person needs has been the subject of several classic experiments.
Some involving putting subjects in deep, totally dark caves for weeks at a time have discovered that the 24-hour-day is almost exactly right for our bodies. The average amount of time our bodies consider a day comes to 24.3 hours, Goel said.
Goel and other Colorado scientists agree that the experiment was small, with only eight subjects, which limits what can be concluded. Nonetheless, the findings justify more experiments like it.
And more camping.
Joel Shurkin is a freelance writer based in Baltimore. He is the author of nine books on science and the history of science, and has taught science journalism at Stanford University, UC Santa Cruz and the University of Alaska Fairbanks.
Originally posted on Inside Science.
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