Snow games: I used to dread winter sports and activities because I often ended up feeling like I was nearing a frostbitten state. Turns out I need more layers to keep warm than most people. But with the right winter gear, you can play all sorts of reindeer games with your kids outdoors. As silly as it is to make snow angels or have a snowball fight, you can burn some serious calories. Sledding downhill then hiking back up will work those hamstrings and glutes while pumping up your heart rate. And old-fashioned ice skating can be a graceful (or clumsy, depending on your skill) way to work out, indoor or al fresco.