How historicly accurate was the Farnese Hercules physique?

I saw this really cool question on this subreddit asking this very questions but it looks like it got deleted with no responses. So i would like to reiteriate this and ask if the Farnese Hercules staues physique was even remotely possible at the time of the statues creation with a training routine and diet that they had in those times? (ignoring the staues height of 317cm and assuming a above average height for the time). Considering some of the statues of Zues or Possioden their physique look semi achivible, but the Farnese Hercules statue is just so utterly insanely yolked that i have a hard time imagining how a greek sculpter could even fathom someone that muscualar unless he had seen it for himself and used it as refrence. So i ask you historiens of reddit to help me answer this question!