In basketball today, players want to run fast, play strong, and most importantly, jump high. How does one improve the height of his or her vertical leap, you ask? There’s a simple answer. Weight training. The two most important muscles for jumping “out of the gym” are the calf and quadriceps muscles. The power in your jump will come from the quad muscle in the front of your thigh. The explosion that lifts you off of the floor to begin with? That starts with having strong calf muscles.