According to Shine (a magazine run by Yahoo!), step aerobics is one of "The Top 6 Calorie-Burning Workouts." Here is the list, in order of calories burnt per hour: Kickboxing - 800 Jumping Rope - 780 Biking - 700 Running - 650 Step - 600 Zumba - 500
I wouldn't take this list too seriously, since there are so many factors that go into determining the effectiveness of a workout. I'm just excited that step is enough on the radar to even be considered!
Oh yeah, and we beat Zumba.
Thanks, Nonie, for the link.