I've been pretty honest here on ED Bites about my struggles with exercise addiction and anxiety, both of which have played a large role in the formation and maintenance of my eating disorder. I began formally exercising in college as a way to "get in shape" and also because I heard exercise was good at helping people manage stress. I was stressed to the max, having leaped right into all sophomore classes my freshman year, and so I began the daily trek to the fitness center at my college.
Before my eating and exercise turned pathological on me, and even now that I am in a very different place, recovery-wise, my exercise sessions were very therapeutic. I do feel better--mentally and physically--after a ride on my bike or a brisk walk. In the past, though, when my anxiety has risen from its usual normal highs into the stratosphere on a straight shot to the ex-planet Pluto, I became dependent upon exercise to help manage this anxiety. And I needed more and more exercise to get the same effects. In short, I was in trouble.
The link between exercise and reduced anxiety is fairly well known in psychology and neuroscience circles, but scientists had yet to figure out how exactly this worked. At this year's annual Society for Neuroscience conference, a group of scientists presented research results that give some indication as to how exactly exercise could help with anxiety management.
In the experiment...scientists allowed one group of rats to run. Another set of rodents was not allowed to exercise. Then all of the rats swam in cold water, which they don’t like to do. Afterward, the scientists examined the animals’ brains. They found that the stress of the swimming activated neurons in all of the brains. (The researchers could tell which neurons were activated because the cells expressed specific genes in response to the stress.) But the youngest brain cells in the running rats, the cells that the scientists assumed were created by running, were less likely to express the genes. They generally remained quiet. The “cells born from running,” the researchers concluded, appeared to have been “specifically buffered from exposure to a stressful experience.” The rats had created, through running, a brain that seemed biochemically, molecularly, calm. ...Anxiety in rodents and people has been linked with excessive oxidative stress, which can lead to cell death, including in the brain. Moderate exercise, though, appears to dampen the effects of oxidative stress. ...“It looks more and more like the positive stress of exercise prepares cells and structures and pathways within the brain so that they’re more equipped to handle stress in other forms,” says Michael Hopkins, a graduate student affiliated with the Neurobiology of Learning and Memory Laboratory at Dartmouth, who has been studying how exercise differently affects thinking and emotion. “It’s pretty amazing, really, that you can get this translation from the realm of purely physical stresses to the realm of psychological stressors.”
Precisely what causes some people to slide over from the beneficial anxiety-reducing effects of exercise and into exercise addiction is unknown. Some of it might be a growing tolerance to the anxiolytic effects of one's current exercise program. Some of it might have something to do with dopamine and the brain's addiction circuits. And some of it, I can't even guess at.
For me, the exercise was a time when I would "hide out" from my anxiety. When I was exercising, I had my iPod blaring and my cell phone switched to vibrate. The report that was due at work the next day didn't matter while I was working out. Figuring out how to pay the bills didn't matter. My sad, pathetic excuse for a social life didn't matter. In the same way one of my friends would stay in bed all day when her anxiety got really bad, I stayed at the gym all day. After exercising, I was usually too exhausted to care much about the things that were making me anxious.
Still, the understanding of how our brains respond to exercise is fascinating and important in helping people better benefit from physical activity and in understanding how to better treat exercise dependence and addiction.