Ha, yea! I just found a way to throw a 15lbs med ball at my gym and did so for 300 reps. I plan to do 300 reps in two separate low/tempo workout days for about 2/3 weeks then ram it up to 600; and about a year from now 1200 like CF said.
I have yet to get the GPP vid but I can “feel” how it could help you. You’re tired and fatigued but yet you still haft to throw the ball explosively; I feel this is similar to the last 50m of a race, you’re tired and fatigued but yet you haft to move your limbs explosively anyway.