The jump rope is an inexpensive and portable conditioning tool that should be in every athlete’s gym bag. In CrossFit-style workouts, you’re asked to perform single-unders, double-unders, or triple-unders, with double-unders being the most common of the three exercises.
Sizing: Jump ropes aren’t something to borrow from the gym or from a friend—you should have your own rope that has been measured for your height. (Here’s how to correctly measure your rope.) You should also have the right thickness for your training purposes: A thicker rope is ideal for a beginner (it slows the rope down and provides more feedback for the athlete) and a thinner rope, like a speed rope, is suited for a more advanced athlete looking for faster rotation.
Skill Work: Most people think of the jump rope in terms of metabolic conditioning, but it’s also a valuable tool for learning how to improve run efficiency. There are some great videos from endurance expert Brian Mackenzie on how to use the jump rope to learn how to “pose run.”