Jumping rope is the exercise that's come off the playground and into the training progsams of everyone from boxers to ballet dancers. Almost anybody can make, find, or buy a jump rope. Once you have one, you can hop, skip, and jump your way into an easy, natural, heart-strengthening exercise. Convenient? Inexpensive? Fun? You bet! And while you're improving your health, you're probably getting better at sports. too, What main idea of the paragraph is that