Good news: You don't have to pump major iron to beat dreaded arm jiggle. To help you get sleek, sculpted arms in time for tank-top season, we asked Michael Olajide, co-owner of Aerospace HPC studio in New York City, for a routine that's low on equipment and big on benefits. And it takes just 20 minutes! This seven-move workout, based on Olajide's Aerosculpt class, requires nothing more than your own body weight, a jump rope, and a set of 1- to 2-pound hand weights.