The Squat Jump can be one of the best plyometric exercises to help you build massive quads and a powerful vertical thrust. It can also wreck havoc on your knees if you're not careful. Be sure to keep your feet shoulder's width apart or farther, and drop your hips right as your feet are returning to the ground. It is crucial that you absorb the weight of your body into your quads. Do not allow your knee caps to lock out.