When he's not playing a prisoner in post-revolutionary France and singing about it, Hugh Jackman is getting buff to play the adamantium-filled Wolverine in the 'X-Men' franchise.

To embody Wolvie, Jackman performs almost all his own stunts, bench presses 315 pounds and leg presses 1,000 pounds -- all by not setting goals and using his brainpower.

As he described his workout, "I do an hour and a half a day in the gym and eat 1,000 calories more a day than I would normally. And I train really hard. I crank up the Godsmack and Metallica. I yell and scream, which helps me get into the character and have a bitch of a workout."

And if he's beaten by an invisible man during his work out, that's even better.