Well ovbiously not in a game, and i as a catcher, if you are pitching to somebody and not a wall the catcher wont like it, it stings enough as is. But if youre throwing at a net i suppose you could, comparing it to batting, to warm up the batters they use weights on their bats, then the bat feels lighter. BUT, ive never heard of anybody, or seen anybody using a weighted ball, i would just reccomend buliding arm stgrenth with weights. Also, maybe when throwing, try buying some strap on weights, like ankle weights, or wrist weights and using them. Good luck.