But everyone has the potential to increase their vertical leap. Jumping is an explosive movement that requires fast-twitch muscle fibers. Usually, if someone is a good sprinter, they will also have a pretty good jump. A marathon runner probably won't. Building strength and training with plyometrics drills will improve your vertical.
Most athletes work on improving strength pre-season, and then add plyometrics.
Athletes use weight training to strengthen the major muscles used to jump, including quadriceps and glutes. The muscles are stretched as you land, so the stretch reflex is invoked, causing you to use more muscle fibers when you jump up. Less is more in plyometrics training. It's also important to spend as little time on the ground as possible. As soon as your feet touch the ground, you should be trying to get off again as fast as you can.