Most of the single-track trails frequented by trail runners are obscured by snow. Tracks made by snowmobiles are great, but many trail runners prefer to chart their own course. That's why snowshoeing, a low-impact sport which can burn calories equal to running or cross-country skiing, is catching on with trail runners. Snowshoe sales are skyrocketing. And snowshoe races are becoming routine in many areas. Snowshoeing is a favorite alternative to downhill skiing for Laskowski: "It's a great, simple sport. You don't need a lot of gear or lessons. And you can get the whole family involved."