Thanks to modern-day wonders like puffer jackets, cuffin' buddies, streaming TV, grocery stores and central air, winter isn't the same survival game that it was for, say, 18th-century trappers (knowledge courtesy of "The Revenant"), or even the same test of homesteading skills that it was for 19th-century pioneer children (knowledge courtesy of "Little House on the Prairie"). Still, even in 2017 with friends like Alexa to tell us when it's too blustery to venture outside, winter comes with seasonally specific health challenges.
I'm talking about sleep, of course. Defining elements of the December-to-March slog, such as reduced daylight, increased sedentariness and social isolation, can interfere with our psychological and physiological states, and, in turn, throw off our sleep patterns. Here's an overview of wintertime rest barriers, with some tips for defeating them.
Less sun, worse sleep
Your body's circadian clock, which partially dictates when and for how long you sleep, is regulated by daily light-and-darkness cycles in the environment. In the morning, light suppresses the release of melatonin, the chief drowsiness-causing hormone, leaving us feeling relatively alert. Once night falls, darkness stimulates the release of melatonin, helping us wind down for bed. But the sun makes a shorter cameo during the winter, and reduced light exposure can affect our moods, our drive for sleep and our daytime energy levels. The short, dark days can throw off sleep in different ways — research has linked deficiencies in Vitamin D (which primarily comes from sun exposure) to both insomnia and excessive drowsiness.
Some of us get really SAD
People with Seasonal Affective Disorder, or SAD, get clinical-grade Winter Blues that stick around for months — five months, on average. SAD, which is technically now called "depression with seasonal pattern," has been linked with several sleep issues. In one 2013 study, SAD-iacs exhibited similar bed-use habits and misconceptions about sleep as innsomniacs (i.e., spending a lot of time lying in bed without sleeping, and believing they've gotten fewer hours of sleep than they actually have). And a study from this year found that people with SAD were significantly more likely than their chipper counterparts to have frequent nightmares and insomnia, as well as be night owls.
The "classic" remedy for seasonal depression is light therapy, which basically entails staring at an intense, bright light box for a half hour each morning. A twist on bright light therapy is dawn simulation, in which people are exposed to a gradually brightening light in their last hour of sleep. In the past two years, however, some researchers have found that Cognitive Behavioral Therapy (CBT) is at least as effective as light therapy in combatting SAD flare-ups. In CBT, a goal-oriented treatment method, people learn to recognize (and correct) the "disordered" behavior and beliefs that are fueling their problem. Unlike psychotherapy, CBT isn't ongoing. A full course typically lasts six or eight weeks, and doesn't necessarily require in-person sessions.
Both light therapy and CBT are also used to fix broken sleep. Shiftworkers have used light therapy to shift their body clocks, and adapt to wonky schedules that might not let them sleep at night, or even at the same time every day. And a sleep-specific version of CBT, called CBT-i, has been the top-recommended insomnia treatment for years.
Cut down on 'me time'
A lack of interest in interacting with other, bundled-up human beings could be a sign of SAD. But even for people without seasonal depression, socializing often simmers down in the winter, when you're less likely to happen into social situations just by being out in the world. And loneliness, studies have found, is connected to a shortened lifespan, heart disease and chronic health issues including poor sleep.
In one 2013 study, brain scans showed that lonely people (as determined by psychological tests) were prone to "microawakenings," which are brief periods of partial arousal, throughout the night. Researchers surmised that their brains were on heightened alert for threat, "perhaps just as earlier humans would have needed to be when separated from their tribe," Slate reported.
Take it less easy
As a topic, wintertime exericse merits a lot of attention, what with the hype over sweat-centric New Year's resolutions, as well as the yearly installment of backlash articles explaining why you actually shouldn't join the gym in January. But the attention is probably well-deserved. It takes more money, effort and planning to get or stay in shape when it's too nippy (in most people's views) to exercise outdoors. And sedentary lifestyles have been linked to poor sleep many times over. So, if frigid jogs aren't calling your name, get thyself to a treadmill or a boutique fitness class or a yoga mat in the corner of your apartment. Just move around, in some capacity, in between episodes of "Tiny House Hunters."
It's (too) hot in here
By all means, get toasty. But for the sake of your sleep, resist turning your home into a sauna. Ideally, you want to set the thermostat at 65 degrees — studies link too-warm sleep environments with sleep disruptions and next-day drowsiness.
You also may want to plug in a humidifier near your bed. Cold winter air already tends to be dry and heating systems only further sap moisture from indoor spaces. If the mucus membranes in your nose and throat dry out, you're more likely to sleep with your mouth open, which can lead to snoring and AM sore throats. Try to keep air humidity levels between 30 and 50 percent.
Though it's not entirely clear why, sleep apnea patients might have the most trouble breathing at night during the winter, compared to other times of year. Air quality may be a factor. So, for people with sleep-breathing disorders, it's worth making sure their sleep environments are balanced in terms of temperature, humidity, atmospheric pressure and air pollution levels.