Beyond that, circuits are a great strategy for building lean muscle mass and shedding body fat. Because of the fast pace, your heart rate is going to stay elevated throughout the entire workout, which means max calorie burning, all without ever having to step on an elliptical.
You’ve also probably noticed this workout has quite a few different strength-training moves, like push-ups, lunges, and burpees. Far too many people underestimate how effective using only your own body can be for building muscle, but you really don't need to throw around huge dumbbells to get bigger. In fact, if you’re starting a new fitness regimen, I’d suggest you start mastering your own bodyweight before even thinking about hitting the weights.