A simple #jumprope can help you get in shape. To find the right rope length, step on the center of the rope and pull the ends up—the handles should come up to your armpits. Keep your knees soft, spine tall, abs pulled in and elbows by your waist. Gaze forward and begin bouncing with both feet—you only need to come up a couple of inches off the floor for the rope to pass under your toes. Jump as long as you can, then jog in place to recover before jumping again.