How Jake Gyllenhaal Became a Fighter for 'Southpaw'

Jake Gyllenhaal made a startling physical metamorphosis for the upcoming boxing drama Southpaw, about a widowed prizefighter looking for another shot in the ring. But the 34-year-old actor, seen in this exclusive poster above as fighter Billy Hope, didn’t just get righteously ripped: He also had to learn the technique of a pro brawler. Gyllenhaal’s trainer, former professional boxer Terry Claybon, insists that the actor wasn’t just fake fighting for the camera. “I wanted Jake to learn how to box so he wouldn’t be out there on the set trying to act like a boxer,” the 52-year-old trainer tells Yahoo Movies. “I pushed Jake to the limit.”

Gyllenhaal trained for six months before filming even began last June in Pittsburgh, PA. As Claybon recalls, Gyllenhaal was nowhere near fighting shape when he started training. First off, he was still fairly thin following his well-documented 30-pound weight loss for last year’s crime drama Nightcrawler. For Southpaw, Claybon confirms that Gyllenhaal returned to his normal weight and then gained 15 pounds of pure muscle.

Secondly, the actor didn’t know much about boxing. “I was blown away over how much work I had to do because of his rhythm, coordination, and timing,” the Los Angeles-based trainer recalls of the first time he saw the actor shadowbox, adding with a laugh that it appeared he’d received some bad coaching prior to their first meeting. After a week though, Gyllenhaal’s sheer determination shined through. “Every day, he was eager to learn more and more about the sport,” says Claybon.

Here are five steps Gyllenhaal took to turn pro:

1. Get on a serious diet and exercise program.
Gyllenhaal was burning so many calories through rigorous workouts that his diet didn’t need to be terribly strict. He did stick to carbs in the morning and protein in the evening. Claybon started him off with three hours of workouts a day: An hour-and-a-half in the morning and an hour-and-a-half in the evening. After two months, the workouts got pushed to six hours a day: Three hours of boxing in the morning and three hours of strengthening, conditioning, and cardio at night. Among the physical feats, the actor would do 1,000 sit-ups in the morning and 1,000 at night. “Gradually we built up, day-by-day, to 2,000. It takes time to do that,” says Claybon.