Super strength?
A lotta talk about the leap from invisibility to added strength, speed and fighting ability. They could have easily shown him to be a fitness/MMA freak. I felt it was an unnecessary add-on, and more clever ways could have been used in the fight scenes.
And what about his post "captivity" physical condition. Unless he'd actually tied himself up for weeks (doubtful), the absence of dehydration, pebble indentations in his butt, chafed wrists from the restraints, etc. were all something a medical exam would reveal as bull.