"Total Recall" star Colin Farrell took a decidedly low-rent approach to getting in Arnold Schwarzenegger-style shape for the action classic reboot.

He watched "The Biggest Loser."

"One of my favorite shows on television is 'The Biggest Loser.' When people that size can lose weight and get healthy again, it is possible for anyone," he told FOX411's Pop Tarts column. "I ate lots of greens and chicken, I didn't order dessert for four months. I stayed off the sugar and got myself on the treadmill. It's just discipline and not that hard when you apply the science to it."

Co-star Jessica Biel, who's one of the fittest actresses in Hollywood, and who previously starred in action flicks like "Blade: Trinity" and "The A-Team," didn't have to do much of in the way of body transformation. She did however have to remind herself all of the movie fighting is make believe.

"The best thing about being an action star is getting to learn really cool martial arts and you feel like you can kick ass in life, but you cannot.