Monday, January 18, 2010

exercise and stress

well, here's yet another bit of research showing that exercise is good for you. apparently, a regimen of regular exercise can help reduce or prevent anxiety, not just in terms of psychological perception but in actual physical composition. it seems researchers have learned that exercise induces biochemical reactions adjusting cellular adjustment that increases the capacity to resist stress and produce less of the stress hormone serotonin--essentially making for a more mellow, stable personality.

check it out. it's a little dated, but i came across it while perusing the archives of the New York Times:
in case the link doesn't work, i've put the full text of the article at the end of this post.

in a way, i guess this helps explain the common perception that so many athletes are a cool, calm, collected bunch (i should note: i differ on this, since i've personally seen an equal number of brash, temperamental, excitable personalities)--cool, calm, and collected to the point of being egotistical and arrogant.

i don't often agree with this latter conclusion, although i can see how people can believe it. a lot of this, i believe, comes from so many athletes just having a higher level of self-confidence and self-esteem derived from an understanding of their competitive abilities. it makes for a measure of self-understanding, which can be translated as just being comfortable with the self, or in common parlance: at peace with the self. you can construe this as resulting in a mellow, relaxed personality less prone to excitement and less likely to get worked up over a sudden source of stress.

but all of this implies a certain reified hubris: that because you believe you're good, you know you're good, so you act like you're good...which is fine if you actually are good, but not so fine if you are not. and it's even more problematic if rises to the point that you believe you're not only good, but better than everyone else--not just in terms of physical ability, but also everything else. this is definitely not good, because it definitely indicates the vices of egotism and arrogance.

what's interesting here is that the research is suggesting a biochemical explanation for the cool, calm, collected demeanor of so many athletes. in essence, the act of exercise is driving the change in personality. which i take as resulting in the following:
  1. the demeanor isn't coming from a belief that you're good or better than anyone else, but from bodily adaptations to physical behavior.
  2. the bodily adaptations therefore don't require that you believe you're good or better than anyone else, nor that you actually be good or better than anyone else.
  3. the personality change can happen to anyone involved in regular exercise, not just athletes but also ordinary people.
  4. the resulting demeanor is beneficial in terms of overall well-being and quality of life.
in which case, we should be exercising not just for the sake of becoming physically healthier, but mentally as well. exercise can help reduce stress, with even a little making a difference. it just has to be done on a regular basis.

so for anyone who says they're too stressed to exercise: you just need to get into a steady routine. you just might be surprised with the results in terms of how you feel...and it also just might make a difference in helping you figure out how to resolve the source of that stress.

so get to it! and relax!

Phys Ed: Why Exercise Makes You Less Anxious
New York Times
November 18, 2009
By Gretchen Reynolds

Researchers at Princeton University recently made a remarkable discovery about the brains of rats that exercise. Some of their neurons respond differently to stress than the neurons of slothful rats. Scientists have known for some time that exercise stimulates the creation of new brain cells (neurons) but not how, precisely, these neurons might be functionally different from other brain cells.

In the experiment, preliminary results of which were presented last month at the annual meeting of the Society for Neuroscience in Chicago, scientists allowed one group of rats to run. Another set of rodents were 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 animals’ 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.

For years, both in popular imagination and in scientific circles, it has been a given that exercise enhances mood. But how exercise, a physiological activity, might directly affect mood and anxiety, psychological states, was unclear. Now, thanks in no small part to improved research techniques and a growing understanding of the biochemistry and the genetics of thought itself, scientists are beginning to tease out how exercise remodels the brain, making it more stress-resistant. In work undertaken at the University of Colorado, Boulder, for instance, scientists have examined the role of serotonin, a neurotransmitter often considered to be the “happy” brain chemical. That simplistic view of serotonin has been undermined by other researchers, and the University of Colorado work further dilutes the idea. In those experiments, rats taught to feel helpless and anxious (by being exposed to a laboratory stressor) showed increased serotonin activity in their brains. But rats that had run for several weeks before being stressed showed less serotonin activity and were less anxious and helpless despite the stress.

Other researchers have looked at how exercise alters the activity of dopamine, another neurotransmitter in the brain, while still others have concentrated on the antioxidant powers of moderate exercise. 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. In an experiment reported at the Society for Neuroscience meeting, rats whose oxidative-stress levels had been artificially increased with injections of certain chemicals were extremely anxious when faced with unfamiliar terrain during lab testing. But rats that had exercised, even if they had received the oxidizing chemical, were relatively nonchalant under stress. When placed in the unfamiliar space, they didn’t run for dark corners and hide, like the unexercised rats. They insouciantly explored.

“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.”

The stress-reducing changes wrought by exercise on the brain don’t happen overnight, however, as virtually every researcher agrees. In the University of Colorado experiments, for instance, rats that ran for only three weeks did not show much reduction in stress-induced anxiety, but those that ran for at least six weeks did. “Something happened between three and six weeks,” says Benjamin Greenwood, Ph.D., a research associate in the Department of Integrative Physiology at the University of Colorado, who helped conduct the experiments. “It’s not clear how that translates” into an exercise prescription for humans. We may require more weeks of working out, or maybe less. And no one has yet studied how intense the exercise needs to be. But the lesson is “don’t quit,” Greenwood says. Keep running or cycling or swimming. (Animal experiments have focused exclusively on aerobic, endurance-type activities.) You may not feel a magical reduction of stress after your first jog, if you haven’t been exercising. But the molecular, biochemical changes will begin, Greenwood says, and eventually they become, he says, “profound.”

No comments: