Jason Pierre-Paul -- 3 Fingers, No Problems ... Pushes 120 lbs With Mangled Paw (VIDEO)

Here's video of Jason Pierre-Paul doing something with 3 fingers that you couldn't possibly do with all five ... pumping a 120 dumbell with the hand he blew up in that fireworks disaster.

It's super impressive ... JPP -- ever in training mode -- breezes through his set like it's nothing, almost making you forget he lost a couple fingers in the accident ... fingers you'd think he needs to lift heavy.

He obviously doesn't ... leading us to our next question.