The ability to jump high is a critical skill not only in basketball and volleyball but also in sports such as rugby, Australian football, soccer, and many others. You need a good “spring,” which means strong muscles with a slew of explosive type muscle fibers and the ability to shorten and stretch them quickly. For those who want to move forward, upper body strength is also important. You will not be a champion jumper if your muscles are mainly slow-twitch rather than quick-twitch muscles. However, with preparation, you can still improve your jump height.