Get a Fighter's Physique: Workout IX
2A REACTIVE ROW
Sets: 2 Reps: 12 (each side) Rest: 30 sec.
Grab a light dumbbell in one hand and rest the opposite side's hand and knee on a bench. Allow your arm to hang . Explosively row the dumbbell to the side of your chest, letting go of the weight in the top position  and then quickly catching it and lowering your arm back to the starting position. That's one rep. Complete all your reps, and then switch sides and repeat.