Chris Hemsworth eats 16 meals a day when he's training for 'Thor'.
The 32-year-old actor admits his preparations to play the hammer-wielding superhero are "extreme" and as he's getting older, he can't withstand the rigours of training the way he used to.
He said: "When I'm in the normal weight range it's fine and I do enjoy training but for 'Thor', everything is to the extreme.
"I'm eating 16 meals a day, I'm lifting as heavy as I can and, over the years, you notice your shoulder can't lift what it once could, or your back feels a bit weaker. Maybe I'm just getting old..."
Chris lived on just 500 calories a day to play a starving seafarer in 'In the Heart of the Sea' and he admitted it made him feel "like s**t" and he was constantly "moody and agitated".
He told Gay Times magazine: "I feel good when I train. When I shot 'The Huntsman: Winter's War', I wasn't getting huge, it was just a functional strength and I was well fed and healthy.
"But if I stopped training for two or three days I'd feel lethargic and lacked energy.
"For something like 'Heart of the Sea', I lost all this weight and felt like s**t the whole time. I was moody agitated. So the more I train, the more energy I have and the happier I am."