Superman is generally shown in most appearances with a single iconic physique: buff as hell. He's also super-crazy-ultra-mega-strong. But as any fan knows, the two aren't generally related: he draws his strength from the light of the yellow sun, and his strength has much more to do with this effect than with his actual musculature.
But do his muscles come into play at all? In those rare instances where Superman is shown with other physiques (such as his emaciated Flashpoint appearance), is his strength affected at all? Has he ever been shown to benefit from working out, or have different capabilities based on his biological fitness?
Or is his strength and endurance completely a function of his Kryptonian idiosyncrasies, and utterly separated from his athletic status?
Edit: Apparently the site wants me to edit this question to justify why it shouldn't be closed, but Mooz nailed it with his comment: "strength" is different from "physique." I don't care what he looks like, I'm talking about whether his biological strength is at all relevant to his Kryptonian-power strength.