Here's a question, don't know if it's worth to open a whole thread about it. Superman basically has strength of plot, right? If he needs to lift an entire continent, he can, if he needs to fly faster than light to travel through time, he can. His heat vision can burn through any material in no time if the plot requires it.
But does any of that exhaust Superman? Will he get breathless/weak after an hour of flight and needs to take a sunbath?
It would be kinda cool if they made an effort in the movie to keep it consistent (at least inside the movie). In Superman Returns he did need to take a sunbath, but because he was stabbed. And then it looked like lifting the crystal island took him just as much power and effort as lifting the airplane in the first act.