This is truly a double-duty exercise. It serves two purposes. It builds explosiveness on the concentric (pulling) portion of a chin-up because each rep is re-set at the bottom of the movement.
It also takes you from single-chinner to multiple-chinner. This could be the result of increased grip strength and scapular retraction, which becomes a necessity since there's no need to swing, hump, or kip your way up.
With all the cardio options out there, it's no wonder we're confused about the best way to incorporate it into our workouts! Coach Robertson summarizes the pros and cons of each variation and helps us with fat-burning program design.