When I can’t get out for a run, my favorite indoor workout is to do a bunch of kettlebell lifts. Swings are an easy way to get your body moving and your heart rate up, and they’re not too hard to learn. For a full-body challenge, get to know the snatch or other lifts like cleans, presses, and jerks. People who compete in kettlebell sport, the style shown in this video, train to be able to do the lifts for 10 minutes straight. That’s a heck of a cardio workout.