A story in The Wall Street Journal suggests that marathons are "the exercise equivalent of crash diets," because they are unlikely to make the runner any healthier in the long run.

There's no evidence that running a marathon leads to lasting weight loss, marathon researchers say. And it's unknown how often such runs initiate or perpetuate a lifetime of steady exercise. Indeed, in a long-term fitness sense, marathons are really sprints; the true marathon is the exercise program that lasts for decades, fitness experts say.
Eric Zorn, an op-ed columnist for the Chicago Tribune, has already raised his hand to confirm that the long-term benefits of hardcore running are elusive. A former marathon runner "gone to seed," Zorn was cited in the report as cautionary evidence. As thousands are preparing for races this weekend in cities throughout the United States, are marathons worth it?