Not Cross Training
You'd be hard-pressed to find a runner who isn't well aware that cross-training is an integral part of any training program, but you'd have little to no problem finding runners who still don't do it. There are many benefits, but the most important is injury prevention — a simple core/hip workout will go a long way toward keeping you strong and healthy. "Cross-training should be a part of your program," says Honerkamp. "The problem is, no one does it until they're injured and they have no choice. And then you're not used to it, and it's annoying. But if you do it a few times a week, and then you get injured or sick and you have to do more of it, it's not this big ordeal."