Everyone knows that exercise is good for them, but is it possible to get too much of a good thing?
While exercise provides many health benefits, at some point working out too hard or too long can increase the risk of injury and have other adverse effects. That usually means intense exercise like training for marathons or endurance activities. Such challenging activities are perfectly fine, maybe even laudable, endeavors, but if you're looking for optimal health benefits, research suggests that more moderate workouts are generally the way to go.
In recent years a handful of studies, all observational, have gotten lots of press for highlighting the drawbacks of exercising too much (in terms of duration and intensity). Newspaper headlines about them—such as "Fast Running is as Deadly as Sitting on Couch, Scientists Find" or "One Running Shoe in the Grave"—may have given some sedentary readers a feeling of schadenfreude. But bear in mind that overdoing exercise, however that is defined, is a problem relatively few Americans need to worry about, since inactivity is far more common and also more harmful. And not all the research on "extreme" exercise has found increased risks.