Great video showing today's Exercise of the Day. Doing exercises correctly is really important. When I am building a workout I always check out a video of any exercises I am unfamiliar with to ensure I know what I should be doing.
Squat jumps are a great workout. They work your legs, but and core and if you put some decent effort in can be part of an excellent cardio workout. Sometime, to toughen up mu workouts, I like to include active rest and squat jumps are ideal for this.