Henry Cavill has admitted he had moments during his Superman training in which he wanted to give up.
The British actor steps into the skin-tight suit and cape to play the superhero in Zack Snyder's reboot Man Of Steel, and enlisted the help of Gerard Butler's 300 trainer Mark Dwight to get into shape.
He told Men's Health: "When I first started working with Mark I thought, 'How the f*** am I going to do this?'."
His workouts had to change frequently, from lifting heavy weights to fat-burning intervals, and there were moments when he wanted to pack it all in.
He said: "When you're knackered and you're drained and you just don't want to go on any more, you're still doing it.
"Maybe we were built to stress and challenge ourselves physically, emotionally and psychologically, and all the rest of it. Maybe that's why we survived physically as a race - we evolved so it becomes fun."
:: The full interview is in the Men's Health December issue - on sale Thursday, November 3.