system
Given the following post, respond as if you're commenting on Reddit:
human
[Superman] How does Superman have such a muscular figure?

I mean, he can bench press the Earth for 5 days straight.  With strength like that, there's no way he could work out the necessary amount to reach the tone and muscle size he has.
gpt
He also is not human. His whole body is different, his cells are different. As we have seen in comics/movies, all Kryptionians have a similar body shape that resembles what we on earth would call a desirable shape.

Superman gets his energy from the sun, not eating. and no matter how long he stays in the sun, he will never get fat.

So, in conclusion, he just looks the way he looks because he is Kryptonian.