Op-Ed: Exercise Science Keeps Missing the Point

February is when a lot of gym shoes start gathering dust—but economist Emily Oster argues in a New York Times op-ed that the real problem isn't our willpower, it's the way exercise research is framed and sold to us. Instead of focusing on how to keep people moving for the long haul, she writes, studies and headlines obsess over which workout is "best": running vs. swimming, walking vs. jogging, Zone 2 vs. something else. The problem is that most of this research is nonsense: The gold-standard randomized trials we'd need to truly compare these regimens are so large and costly they rarely exist.

What we mostly have, Oster explains, are observational studies that blur the line between correlation and causation. Swimmers in one study looked worse off than runners—not because swimming "doesn't work," but because swimmers tended to have more health risks to begin with. Similar flaws underpin buzzy claims about step counts and "one minute of vigorous equals an hour of light" activity. Oster's advice is that people find an exercise tailored to their own likes and lifestyle, and stick with it on a regular basis. "It doesn't really matter which exercise people do—they just need to do it past February." (Read the full piece.)