The link between a sedentary lifestyle and anxiety was reinforced recently by new research comparing sedentary mice and mice that exercise. The study, published in the Journal of Neuroscience and covered in the New York Times, where I first learned about it, suggests that habitual inactivity can cause increased anxiety in animals that don’t move around much.
Researchers at Princeton University compared the behavior and brains of mice that were allowed to exercise on wheels in their cages to those who instead "sat quietly." The mice that were active showed more inclination to explore new environments when given the chance, an indication of less anxiety. When dunked in cold water, as stressful for mice as it is for humans, the running mice reacted more calmly than the sedentary ones.
This effect has been observed before, but the new study delves deeper into the mechanisms behind it. Analysis of the rodents’ brains revealed that the running sparked the creation of excitable neurons that prompt activity, and resulted in a huge new supply of neurons that produce GABA, which has a soothing effect on the nervous system.
Is there a connection between our own sedentary lives and our epidemic of nerves? According to the Anxiety and Depression Association of America, anxiety disorders are the most common mental illness in America, afflicting 18 percent of the nation – some 40 million people. Eleven percent of middle-aged women in the U.S. take anti-anxiety medication.
Correlation is, of course, not causation. But this latest study adds to other science that connects the amount we do or don’t move our bodies and our mental health.
Part of the problem, of course, is that too many Americans see movement as something to be done at a discreet time. Work at a treadmill desk, your own little exercise wheel in your own little cage! Drive to a spin class at the gym! There, you can ride up imaginary hills with your fellow creatures trying to escape the perils of the sedentary life!
The normal human solution, to walk around the world as we work, gather food, and play, is increasingly inaccessible to us. And even when it is not, we frequently perceive it to be inaccessible. According to the Federal Highway Administration’s 2009 National Household Transportation Survey, 68 percent of the trips taken by U.S. residents between ½ and 2 miles in distance were made by vehicle. Only 23 percent of such trips were made on foot.
One-third of respondents reported no walking trips whatsoever in the previous week.
"The greatest barrier to walking more is the perception of too much traffic, not enough street lighting, or wide road crossings," reports the FHWA. "People are also concerned about crime, had no nearby paths or sidewalks, and were too busy to walk more often."
But "working out" is never going to be a solution for everyone, or even for most people. It can be expensive and strenuous and dull. Instead, we should be encouraging people to see walking (or biking) as part of their daily routine -- not a special activity to be engaged in wearing special shoes on a special path, but simply the sensible way to get from one place to another. Imagine how much calmer we might be.
Andrew R. Cline, associate professor of media and journalism at Missouri State University, has a blog in which he advocates what he calls "'the 1-mile solution." He suggests that people use a simple tool such as Walk Score to assess what services are within a one-mile radius of their homes, and then simply walk or ride a bike to make those trips. Cline writes:
I’m … suggesting that we … put effort into an idea that is sustainable and could grow the numbers by creating a habit. It is, after all, mostly a habit that puts us behind the wheel of a car to travel one mile. It’s habit that makes the risk and expense of a 1-mile car ride seem normal.
If people do try their own "one-mile solution," they may discover exactly what the FHWA was talking about: a pedestrian environment unpleasant or downright hostile to travelers on foot. Maybe then we'll finally have the political capital we need to lobby for real infrastructure improvements that allow people can get the activity they need in a natural human way, rather than spinning like mice on a laboratory wheel.