Did you think jump roping was just for kids? With the rise in popularity of CrossFit and other fast, dynamic workouts, speed ropes are a serious fitness trend. And not just any jump rope can be a double under rope. To get the extreme speed and precision needed for these more demanding jumps, you need a rope designed for workouts, like the Elite SRS speed ropes. These purpose built double under ropes feature ball bearing handles capable of 6-7 rotations per second for even the fastest reps.