Today's New York Times included an article on exercise during economic downturns.
We suspect that job stress is probably higher during economic upturns, when population health actually seems to deteriorate. But ameliorating stress is cited in the article as a reason why during downturns folks at least on Wall Street flock to gyms and yoga classes. These two facts seem at odds insofar as the implicit source of stress is the recession itself; but maybe they aren't at odds if upswing-stresses never get treated with exercise because of time constraints.
The article also cites career counselors who tell unemployed clients to focus on fitness, which is interesting and certainly fits the statistical findings of better health during downturns.
To be sure, the current downturn is also a little different from others in that there has been a massive hit to financial wealth. In a paper I'm currently working on, I model time use, which can include exercise, controlling both for changes in stock prices and for changes in unemployment. As you might expect, the two suggest different things. Higher unemployment can reduce the price of time and incentivize health behaviors that are otherwise viewed as too costly in terms of time. Lower stock prices lower wealth and through a pure income effect can lead to lower purchases of everything, including leisure (and exercise) time.