Research: Exercise Reduces Anxiety

For the anxious, let's go straight to the facts, at least some of the facts: in research conducted at the University of Colorado, rats taught to feel anxious showed increased serotonin activity in their
brains, while other rats that had run for several weeks before being stressed
showed less serotonin activity and were less anxious despite the stress.Gretchen Reynolds writes in the New York Times Well column that anxiety in rodents and, yes, people has been linked with excessive oxidative
stress. Reynolds reports on another experiment at the University of Houston in which rats whose oxidative-stress levels had been artificially increased were found to be extremely anxious when faced with unfamiliar terrain during laboratory testing. But rats that had exercised, even if they had received the oxidizing chemical, were relatively nonchalant under stress. No word yet on how, exactly, exercise reduces anxiety, but Reynolds does offer some advice for those who are anxious to be less anxious: it takes time to work. In the University of Colorado experiments, she reports, 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.

Read more in the New York Times.