There's no length an elite actor won't go to in order to heighten their performance. Most fans make the mistake of presuming that physical stunts or fight scenes are the most demanding — but this isn't the case.
If you were to do a random pole of your favorite actors in Hollywood, the overwhelming majority would say that the scenes they hate filming the most are sex scenes. Mostly, because the actors really do get aroused from time to time — and it's as awkward as it sounds.