I always get terrible sleep when I go camping; from insect bites, to animal-related calls, to sleeping on a slightly uneven and rocky surface even with a foam roll, I never seem to get a good night’s rest. The worst feeling is being blasted with the morning sun after it rises. This is amusing to think about now after reading this study recently published in Current Biology. This study was conducted by colleagues of mine at the University of Colorado-Boulder. I know Montegraphia would have loved to be a participant in this study because the participants got to hang out in the Rocky Mountains for two weeks! Sleep wasn’t measured per se, but activity was with an infrared wristwatch.

ResearchBlogging.orgFirst, the researchers examined how much light was emitted from living in a lab versus out in nature. It’s no surprise that the intensity of light exposure in nature was 100-fold higher (10,000 vs. 1,000 lux) than that in the lab. The body was also highly responsive to this large amount of light exposure offered by nature. For example, dim light melatonin onset (DLMO)–which is a physiological marker of internal clock time–was significantly earlier in nature versus the lab. It usually occurs around the time that one goes to sleep. The release of melatonin is fairly stagnant throughout the night, but obviously wanes towards the early morning. An earlier DLMO was beneficial for early morning alertness because the melatonin, which induces sleepiness, was largely cleared by the body. Exposure to natural versus electrical light also benefited individuals who go to bed later by allowing their internal clocks to shift quicker in response to light.

Overall, this is a really great study demonstrating that modern life is not always beneficial for our sleep hygiene. Actually, I’m not familiar with many studies showing the benefits of modern life for sleep hygiene…..

Shenandoah State Park

Wright KP Jr, McHill AW, Birks BR, Griffin BR, Rusterholz T, & Chinoy ED (2013). Entrainment of the human circadian clock to the natural light-dark cycle. Current biology : CB, 23 (16), 1554-8 PMID: 23910656