This is a speed-strength, lower-body plyometric. This exercise begins like the height jump, but continues. You will need to line up two sets of boxes or steps. The typical distance is about 4 feet between the pair of boxes.
1. Begin by standing atop an 18 inch or taller box (if you have no experience with this exercise, use a standard bench such as one for bench presses, etc.).
2. Jump off the box and flex your knees so that when you hit the floor/ground that they bend 3-4 inches.
3. Take care when you jump not to be stiff legged or to land flat footed; land on the balls of your feet, flexing your knees.
4. As soon as your feet hit the ground/floor, propel yourself up, landing on the second set of boxes, i.e., jump onto the box without any loss of motion.
5. Hop off the box and return to starting position atop the 1st box for beginning of next repetition. If both boxes are the same height, you can land atop the second box, turn to face the first box, and repeat the movement for the required reps and sets.