As biological clocks go, maybe you feel like yours is way out of sync. Maybe you feel like this can't be helped because you've always been a night owl and you feel more alert at night anyway. If this is the case, you might want to consider how artificial light (TV, computer, lights) affects your late night sleep schedule.
In a study published August 1 in the journal Current Biology, researchers found subjects who spent more time in natural light shifted their bed and rising times earlier by two hours.
This finding was discovered through camping. Researchers had eight subjects go camping for a week in an attempt to synchronize their biological clocks to natural light. The subjects (six men and two women at a median age of 30) were asked not to use any artificial light; only light provided by either the sun, stars or fire was allowed.
To understand the effect natural light, a week prior to the study the subjects were asked to wear a wristband device that measured the timing and amount of light exposure the wearer was receiving. Following their normal routine, the device was able to gather information about the subject's usual amount of light exposure.
During the camping trip, researchers found the amount of sleep remained the same, but subjects adjusted their bed and rising times by about two hours earlier. The subjects took their cues from the natural light-dark cycle. Their biological nighttime's started after sunset, and their mornings after sunrise. Even for people categorized as night owls or early bird, all followed this signal provided by natural light.
According to the study's summary they conclude, "Furthermore, we find that after exposure to only natural light, the circadian clock synchronizes to solar time such that the beginning of the internal biological night occurs at sunset and the end of the internal biological night occurs before wake time just after sunrise."
This conclusion challenges the notion people have that they're stuck in a certain rhythm of sleep - people who feel more awake at night or have an easier time in the morning. It's hard to break the cycle since it's natural to use devices with a backlight well into the night; however, with more and more artificial light in our world, the further we step away from the natural light-dark cycle.
The study was led by Professor Kenneth Wright, who works in the department of integrative physiology at the University of Colorado in Boulder.
In the news release, Professor Wright is quoted saying, "Some people are morning types and others like to stay up later. What we found is that natural light-dark cycles provide a strong signal that reduces the differences that we see among people—night owls and early birds—dramatically."
One thing this study has us consider is how artificial light can affect our sleep pattern. Before artificial light, our bodies followed this natural light-dark cycle more readily. With the invention of iPads, computers, television and light bulbs, our exposure to light is lengthened well into the night throwing off this natural light-dark cycle.
Ideally, taking a week long camping trip would do well for most people. Even taking a few days and cutting your exposure to artificial light can help. For those who can't take the time, try a few other things to lessen your exposure to artificial light. Keep the blinds open during the day to let in the light. Try to restrict the amount of nighttime television. Avoid using screens with a backlight.
Access the study.