Oh for sure his heart/cardio is still in great nick I'm certain - especially with his weekly training and undiminished love of football. I'm sure his performances in training are as enthusiastic as anyones.
But it's a bit like when you're in a gym and see a 40 year old man with a beer belly who can run for an hour on the treadmill without stopping or any apparent discomfort - physically fit compared to most of society but never optimal. Or maybe that was friends' dads that I knew.
Some see it as harsh and it's United's own fault for paying him what he gets, but for his wages you'd expect a Cristiano Ronaldo -esque athlete at least in terms of his physical appearance - regardless of any technical regression. I don't think we expect anything special either - as someone alluded to earlier, we're just talking about him being lean and making the small lifestyle choices with his diet (or
sacrifices if you want to be overdramatic) that his role and pay check demand.