If you're running on snowy, slushy, or wet surfaces, we recommend wearing a shoe that includes some form of waterproofing, whether it's a Gore-Tex membrane or a water-repellent treatment. This will help keep your feet dry and warm over the course of a run and prevent snow that sticks to your shoes from seeping in when it melts due to the heat your body gives off. Once your feet are wet they'll get cold much quicker, potentially forcing you to shorten a run and head home. Keep in mind, however, that if you aren't running through deep snow, Gore-Tex or other waterproofing might be overkill. "You're probably going to step in a puddle and it's going to go above your ankle anyways," says Kilgore.