Jake Gyllenhaal Did 2K Sit-ups a Day for Movie

Jake Gyllenhaal plays a prizefighter in Southpaw, out this summer—and he went to great pains to bulk up for the role. He started with three hours of workouts per day and worked his way up to six hours a day; those workouts were split between boxing and strength training/conditioning/cardio. One example of his daily to-do list: He worked his way up to 2,000 sit-ups each day, half in the morning and half at night, his trainer tells Yahoo News.

Gyllenhaal had lost 30 pounds for last year's Nightcrawler, so he had to get back to his normal weight and then add 15 pounds of muscle—plus he had to learn how to box—which explains why he trained for six full months before beginning filming. By the end, he was decent enough to spar with actual pros, though his trainer notes that they weren't exactly "trying to take his head off." (Click for a slideshow of actors who've lost a lot of weight for their roles.)