Vertical Jump
The vertical jump is the simplest jumping exercise possible and is an accessible way to introduce jump training to any athlete with no equipment.
It also allows balance over the feet by eliminating any need to jump forward onto a box, so is arguably more appropriate for weightlifting than box jumps.
Additionally, having to arrest the full downward force rather than the drop being shortened by landing on a box improves the ability to productively absorb force and improves the foundation for elastic contribution to a following concentric motion like a depth drop.
Perform a standard countermovement jump straight up as high as possible. Stand with feet around hip width, brace the trunk, bend at the knees and hips to load the legs and swing the arms back, then swing the arms up as you push as aggressively as possible against the ground. Absorb the landing in a strong stance by bending the knees and hips.
Demand on actual leg and hip power can be increased by removing the swinging of the arms—hold the hands loosely at the chest.
Purpose
The vertical jump is a basic exercise to develop explosive leg and hip extension. It can be used as an easy and accessible introduction to jump training, when a box isn’t available, or when an athlete is nervous about jumping onto a box. It also allows balance over the feet by eliminating any need to jump forward onto a box, so is arguably more appropriate for weightlifting.
Programming
Vertical jumps should generally be done for 3-5 reps per set, with 3-10 sets. In weightlifting, they are usually done at the end of a training session. This prevents their fatiguing the lifter for the performance of more sport-specific speed-dependent lifts, and also helps improve explosiveness by forcing the body to recruit more and higher-threshold motor units when partially fatigued.
Variations
Vertical jumps can be done without a countermovement, with a full squat countermovement or from the bottom of a squat, with one leg, to the side, from a seated position, and without an arm swing to focus maximally on leg and hip power—hold the hands loosely at the chest.