Think jumping rope is just for CrossFit fanatics or double-dutch-loving fifth graders? No way! Jump ropes are all the rage on the fitness scene, from boxing to barre studios—and for good reason. “Jumping rope is one of the best ways to burn the most calories, and it tones the entire body as you’re jumping,” says Amanda Kloots, creator of “The Rope” and “The Dance” classes in New York City. “Since becoming an avid jumper, my entire body has completely changed—especially my arms and abs.” Kloots’ popular jump rope-based classes focus on some fitness fundamentals: endurance, coordination, and speed. With those…