Jumping rope vastly improves the cardiovascular and respiratory systems. It greatly improves coordination, reflexes, and stamina; increases vertical jumping ability; strengthens the shoulders, forearms, wrists, and grip. The thigh muscles are utilized in a fashion that will have anyone convinced they have muscles never used before. You will realize that they are not quite as well conditioned as you thought. Nothing comes close to rope skipping when developing the calves and balls of the feet. It is also associated with wrestling and boxing training.