One benefit of gym membership is the wide variety of cardio machines. Treadmills, ellipticals, rowing machines, stepmills . . . but while I find these machines a convenient way to get my hear rate up, I get bored easily when doing an aerobic workout indoors. I have created some strategies to fight cardio machine ennui, like mixing it up with interval workouts and rocking out to new playlists. What about you?