Spider-Man 1 with Tobey Maguire tells the story of how Peter Parker acquired his abilities.
Most of the time he is fully clothed. However, we are privy to at least one scene (the day he gets bit) where we see a super-skinny, ailing Peter Park about to turn into the Webcrawler.
We see a little bit of biceps here, but his chest is flat and he almost looks anorexic.
The next day, we see the new, improved muscular Peter Parker:
In real life, we know there was a lot of diet and exercise that came with this transformation.
My question is this: Did they film skinny Tobey first, let him bulk up and then film the rest of the movie? If so, how long can a movie studio wait while its primary actor works on his character? (e.g. in this case, gets ripped).