If you need to improve your jumping ability in a short amount of time, you'll want to focus on training your muscles rather than building them. Instead of focusing on heavy weight lifting, you'll need workouts that focus on explosive power and reactive power exercises. These exercises are performed with lighter weights or no weights, and simulate jumping with powerful movements in one direction, or up-and-down movements.
Calculate your current jump height by jumping as high as you can against a wall and marking the wall with a piece of chalk or other marker. You can also videotape yourself, placing the camera on the floor, with markings or some other reference point on or near the wall and your feet. During video playback, stop the picture at the peak of your jump to measure your leap that way.
Practice explosive strength exercises. Explosive strength is your ability to make a powerful muscle contraction in one direction, such as a sprinter moving out of the starting blocks during a race.
Explosive strength exercises include box squats, which have you sitting on a box or bench with weight on your shoulders, then standing straight up. One-leg split-squat jumps have you standing behind a box or bleacher row and placing one foot up. Use your up leg to push yourself straight up as high as you can. For box jumps you stand behind a box and jump up with both feet. For paused jump squats, use 15 to 30 percent of your maximum weight and perform standing squats by going down, waiting three seconds, then jumping upward as high as you can.
Perform six to eight repetitions of explosive strength exercises per set.
Practice reactive strength exercises. Reactive strength is your ability to coordinate two muscles or muscle groups to create a quick or powerful movement. Bending your knees downward prior to jumping up to dunk a basketball is an example of reactive power.
For depth jumps, stand on a box or other stable platform about equal to your current vertical jump. Jump off, then spring upward. Reactive jump squats have you using 15 to 30 percent of your maximum weight and performing repeated standing squats in a rhythmic fashion. Skip with high knees across a gym or field. Sprinting and vertical leaps are also good reactive power exercises.
Do three repetitions of the jumps and five to 10 of the reactive squats per set.