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.
Throughout most of human history, humans went to bed shortly after the sun went down and woke up in the morning as it rose. There were candles and later oil lamps, but the light was not very bright so people still went to bed early.Skip to next paragraph
Subscribe Today to the Monitor
Then came Thomas Edison and the incandescent light bulb and everything changed, including our sleeping habits. So, if you have problems getting to sleep at night or are a miserable person to be around in the morning, blame him.
Scientists at the University of Colorado Boulder found that if you live by the sun's schedule, you are more likely to go to bed at least an hour earlier, wake up an hour earlier, and be less groggy, because your internal clock and external reality are more in sync. The sun adjusts your clock to what may be its natural state, undoing the influence of light bulbs.
RECOMMENDED: Are you scientifically literate? Take our quiz
The work is published in the current issue of the journal Current Biology.
The disconnect between the outside environment and sleep is one reason why even native Alaskans have problems sleeping in the almost endless days of the Arctic summers, and get depressed during the long nights of winters.
The subjects in the Colorado study lived more normal lives.
"We weren’t studying people who had sleep difficulties," said Kenneth Wright, an integrative psychologist at Boulder. "The amount of sleep they got did not change. What changed was the timing of their sleep and the timing of their [internal] clock relative to when they slept."
The researchers took eight adults, average age around 30, and followed them around the normal course of their lives for a week. The subjects spent most of their time indoors while working, studying, eating, and sleeping. Most of the light they encountered was artificial. Then, they sent the same people out camping.
Sleep and light were measured daily and the hormone melatonin every hour across 24 hours, once after the week of living at home, going to work, school, and then after a week of camping.
Melatonin is the "hormone of darkness," said Namni Goel, a psychologist and sleep researcher at the University of Pennsylvania in Philadelphia. Scientists use the hormone to measure photoperiods, or the physiological response that organisms have to cycles of daylight and darkness.