The Jump Squat is a staple of plyometric training, which develops explosive speed, power and jumping ability. The exercise forces the lower body to triple extend—a coordinated extension of the hips, knees and ankles—against low to moderate resistance, developing the muscles' ability to produce force as quickly as possible.
According to the Strength and Conditioning Journal, "Jump Squat training can offer greater gains in lower-body power output when compared with lower-body resistance training or plyometric training alone, and may be equally as effective as combined resistance and plyometric training at improving jumping ability."
While Jump Squats are proven effective, a variety of techniques can be used, including placing a barbell across the shoulders, similar to a Back Squat, and holding dumbbells with each hand. These are particularly effective at challenging muscles to propel the body off the ground for maximum power; however, they limit natural motion and reduce the speed of the movement.
For more sport-specific Jump Squats, experts recommend using either bodyweight or a weight vest. The lower weight allows for natural movement of the upper and lower body and develops muscles at speeds similar to game-time conditions.
For maximum performance improvements, combine bodyweight/weight vest sets with dumbbell/barbell variations. Begin with the Bodyweight Jump Squat to master the movement and develop sufficient strength; then add the weight vest, dumbbell or barbell. Once you're good with all variations, perform two Jump Squat routines per week, one with dumbbells or a barbell, and the other with bodyweight or a weight vest.
Watch the following videos (above) for variations of Jump Squats that you can implement in your training program.