Derrick Henry is proving once more he's superhuman ... showing off a pair biceps on Wednesday that'd make even the biggest pro bodybuilder envious.
It was apparently arm day for the NFL superstar on Wednesday ... and in a video of his sweat sesh posted by his trainer, you can see the running back had a whole lot of bis and tris to work out once he got in the gym.
Henry -- sans shirt -- got a pump in through various different exercises ... including a bunch of curls with heavy weights -- and some pushups with a plate on his back.