Why Your Workout is Causing Weight Gain

You’re eating too much protein or carbs.

Marathon runners might need to carbo load before the big day, but if your runs last less than an hour, you don’t necessarily need to fill up on carbs—the same goes for protein. Most Americans actually already get enough protein in their diets, says Armul, so you don’t need to focus so much on getting more of it—even if you’re weight training or HIIT-ing it more. “People love to talk about protein because it is essential, but if you eat too much, you’re going to gain weight, as it will be extra calories,” she says.