Like millions of adults, you probably haven't picked up a jump rope since grade school. But if you're looking for a killer calorie burner (almost 200 calories in 15 minutes) that's simple enough to entertain kids on a playground, yet intense enough to help condition the world's most chiseled prizefighters, it could be time to grab a rope and brush up on some of those schoolyard rhymes.
Here's what you can get from 30 minutes of rope jumping:
