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For any jerk variation, the skill consists of using the hips and legs to create upward momentum, then dipping a second time to receive the load in a partial squat. The need to control two dumbbells heightens the demand for coordination and accuracy. Athletes that master the dumbbell push-jerk will develop a solid “lockout” of the arms and intuitive understanding of the overhead position.

"Double-unders require the athlete to propel the body upward and lift the feet up to several inches from the ground while making small, fast circular movements with the wrists in order to execute multiple turns of the rope with each jump. They develop dynamic balance, speed, quickness, agility, coordination, concentration, and cardiorespiratory efficiency." —Buddy Lee, "Jump Rope Basics, Part 2" (adapted)

The box step-up is similar in mechanics to any lunging variation. The athlete must use the strength of one leg to elevate themselves. The higher the box, the greater the demand on both strength and flexibility. Although often used as a scaled version of the box jump, the step-up can provide a challenge to even the most advanced athletes.