Expert Dave Newman dissects the double-under and offers tips that transfer over to triple-unders.

"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 thruster requires a long line of action against the normal force of gravity with a load plus body weight, creating one of the most profound accelerations possible. The movement works from full flexion to full extension at the ankle, knee, hip, shoulder, and arm, and involves most of the major muscle groups. These factors earn the thruster its reputation as "the most draining of all exercises."