|Basic InformationLatest News|Health Tip: Get Moving and Stay ActiveWellness Visits for Better Well-beingGet Ready, Safely, for the Great American EclipseTV Binge-Watching May Leave You Like 'The Walking Dead'Health Tip: Plan for a Heat WaveGivers Really Are Happier Than TakersHealth Tip: Think Smart During a Hot SpellHow Safe and Effective Is Your Sunscreen?For Drivers, Hands-free Can Still Be a HandfulIt's Never Too Soon to Safeguard Your BonesImpact of Video Games on Brain Varies With Game Type, Strategy'Loneliness Epidemic' Called a Major Public Health ThreatDoes Less Sleep Make You Less Healthy?Need to Calm Down? Try Talking to YourselfJust Thinking You're Less Active May Shorten Your LifeHealth Tip: Protect Your Skin at WorkGolfing and Gardening Your Way to FitnessTeaching an Old Brain New TricksCan't Get to the Gym? Work Out in Your Office!The Scoop on Avoiding 'Brain Freeze'How Much Sleep Do You Really Need?Healthy Heart in 20s, Better Brain in 40s?Health Tip: Getting Too Much Sun?Sunscreen Application Doesn't Provide Complete Body CoverHealth Tip: Protect Your Eyes During SummerHealth Tip: Check the Water Before SwimmingFlip-flops: Fun in the Sun, but Tough on FeetSound Sleep May Help You Junk the Junk FoodWhen Opinions Threaten FriendshipsBetter Diet, Longer Life?Health Tip: If Lifestyle Interferes With SleepDocs Should Counsel Even Healthy People on Diet, Exercise, Experts SayDaily Jolt of Java May Bring Longer LifeHealth Tip: When Air Quality is PoorKeep Your Summer Cookouts SafeMany Parts of the World Lack Soap for Hand-WashingHealth Tip: Yoga Before BedGetting Over GuiltHealth Tip: When Summer Heat Gets IntenseDon't Let Summer Strain Your BackFor Many, Friends Are Key to Happiness in Old AgeCould a High IQ Mean a Longer Life?Presence of Smartphone Cuts Available Cognitive CapacityProtect Your Skin From the Summer SunHealth Tip: Create a Food-and-Activity JournalHow to Dodge Summertime ThreatsHealth Tip: Basic Beach SafetyWallpaper May Breed Toxins: StudyHealth Tip: Are You Well Enough to Travel?Can Smartphone Use Bring on Carpal Tunnel Syndrome?LinksBook Reviews
Time Outdoors May Deliver Better Sleep
by By Amy Norton
Updated: Feb 2nd 2017
THURSDAY, Feb. 2, 2017 (HealthDay News) -- Spending time in the outdoors may improve your sleep, a small study suggests.
Researchers found that a week of winter camping reset the body's "clock" to be more in tune with nature's light-and-dark cycle. The result was longer sleep.
The findings, the study authors said, add to evidence that time in the sun and the dark helps people get to sleep at a decent hour.
The study also highlights how modern living -- so heavy on artificial light -- may thwart our sleep.
"It's clear that modern environments do influence our circadian rhythms," said Kenneth Wright, the study's senior researcher.
Circadian rhythms refer to the shifts in the body's biological processes that happen over 24 hours, partly in response to light and darkness.
But while our ancestors may have gone to bed early and risen with the sun, that's not true today, said Wright, a professor at the University of Colorado, Boulder. Many people get little outdoor time during the day, then stay up late -- eyes trained to artificial light from glowing computer, phone and TV screens.
In a 2013 study, Wright's team found that a week of summer camping -- with no smartphones -- reset people's internal clocks to be in rhythm with nature's.
Saliva samples showed that levels of the "sleep hormone" melatonin shifted compared with a typical week at home. Melatonin levels started to rise around sunset, and the campers' "biological night" kicked in about two hours earlier.
Accordingly, the campers turned in much earlier than their usual midnight bedtime at home. They also woke up earlier, closer to sunrise.
For the new study, published Feb. 2 in Current Biology, Wright's team recruited five hardy volunteers for a week of December camping in the Colorado Rockies. Again, the researchers used saliva samples to detect shifts in campers' melatonin levels, versus a week at home.
Campers' biological nights started over 2.5 hours sooner, Wright said, and they went to bed earlier.
There was, however, one difference from the earlier study. Winter campers did not rise earlier. So they ended up getting more than two hours of extra sleep.
The study doesn't establish a direct cause-and-effect relationship between time outdoors and better sleep. And Wright said temperature may have played a role in the extra morning shut-eye. People may have simply preferred to stay in the warmth of their tents and sleeping bags than face the early morning chill, he noted.
In a second experiment, the researchers had 14 people either spend a weekend at home or camping -- this time in the summer. They found that even a weekend outdoors caused people to shift their biological clock.
In contrast, people who stayed at home showed the opposite pattern: On weekends, their biological night started even later than it typically did on a weekday.
Why does all of this matter?
According to Wright, there is evidence that people with "late" internal clocks face some health risks. They have higher rates of obesity, diabetes and depression, and are more likely to suffer daytime fatigue and accidents.
"We don't completely understand why that is," Wright said.
But, he added, it is wise to not only get enough hours of sleep, but to make sure you're sleeping at the "right" times.
A researcher who was not involved in the study agreed.
There is evidence, for example, that exposure to morning light is associated with appetite and weight control, said Dr. Phyllis Zee.
She said the new experiments are important because they demonstrate just how powerful exposure to natural light -- and darkness -- can be.
"Just two days of summer camping reset people's clocks," said Zee, director of the Center for Circadian and Sleep Medicine at Northwestern University in Chicago.
If you're not the camping type, there is good news. "This study is not about camping," Wright said.
He encouraged people to get out in the sun when they can each day, then minimize bright artificial light at night. That's particularly important, Wright said, when it comes to blue/green light like the glow from your phone or computer screen.
In the natural world, Zee explained, blue/green light is most pervasive in the morning. Later in the day, natural light shifts toward a red/orange frequency.
She and Wright said research like this can also inform architecture and lighting design. If people are holed up indoors every day, they should be exposed to natural light -- or artificial light that mimics natural light -- as much as possible.
The National Sleep Foundation has more on circadian rhythms and sleep.
This article: Copyright © 2017 HealthDay. All rights reserved.