Jake Gyllenhaal got punched out and trained until he puked in preparation for Southpaw

Jake Gyllenhaal is no stranger to grinding physical hardship in pursuit of dramatic excellence. For his acclaimed turn in neo-noir pot boiler Nightcrawler last year, the actor got into character through what can only be called manorexia—dropping 30 pounds on a diet of chewing gum and kale salads and running up to 15 miles a day. For the reality-based thriller Everest (Sept. 18), Gyllenhaal prepped for his role as an experienced mountaineer by simulating altitude sickness in a hypobaric chamber and trekking in Italy’s Dolomite Mountains.

When it came to portraying a boxer in the sports drama Southpaw (Jul. 24)—a light-heavyweight champion who must assume care for his young daughter after personal tragedy strikes, fighting his way through rage and loss to redemption—the actor hit the gym. Not just any gym. Director Antoine Fuqua had Gyllenhaal doing two-a-day workouts seven days a week for six months at fitness facilities across the country including Floyd “Money” Mayweather’s Mayweather Boxing Club in Las Vegas and Church Street Boxing Gym in New York City.

The upshot? Gyllenhaal’s absurdly rippling abs in the film stand as enduring testimony to his commitment to process but also to a kind of no-pain-no-gain Method acting immersion that resulted in hard-to-fake ring realism.

“I watched him vomit in the gym and almost pass out,” says Fuqua. “I watched him take hits, gut shots in the ribs, get dropped. He took punches and was swollen for real. I’d watch to see if he would stop or drop. He’d keep going. I pushed Jake to the edge and he went right there with me.”

He added: “There was no stunt double. He shot every boxing scene himself. Not only was he really in there, he was calling to do more.”

For his part, Gyllenhaal felt the physical preparation would help present the outward manifestation of his character’s inner ordeal. “I made Southpaw because it was about the idea of anger,” he tells EW. “A man dealing with anger and how it affects your life. And how you overcome anger. How it can be helpful without the hatred in it.”