Step aerobics have been around for a while, but they’re still one of the best ways to burn a lot in a little bit of time. Choose a 10- to 12-inch step platform and you’ll sizzle about 107 calories in 10 minutes. No Step class at your gym? Find a plyo box and create your own 10-minute workout says Stehly: Warm up for three minutes by stepping up onto and down off the box, one foot at a time—quickly enough to break a sweat but not so quickly that you’re compromising form or safety. Then add in five explosive box jumpsevery minute, on the minute, to really get your heart rate up. Remember: It’s only 10 minutes; you can take a break afterward, not during!