So you fancy yourself a bit of a runner? You’re a fan of carb loading. You idolize Forrest Gump. You can’t stop listening to “Eye of the Tiger.” And you’ve nicknamed yourself Usain Bolt. If...

The first week of class this semester, I remember having a serious case of “powder flu,” which is a severe and chronic need to hit the slopes. And it was the worst I’d ever experienced. It seemed...