Jake Gyllenhaal worked hard for his role as boxer Billy Hope. The actor was seen watching Mayweather fight in Las Vegas last year as part of his preparation for the role. He was also seen spending plenty of time with the fighters in Mayweather’s gym. The actor’s intense preparation will be seen in Southpaw, which will be releasing in theaters on July 24. The actor has been seen gaining weight up to 45 pound. His workout regime is said to be insane as he looks like a monster in Southpaw. He even made a point of learning boxing and maintaining his physique of a world boxer. His transformation was dramatic as he was earlier seen in Nightcrawler where he lost 30 pounds. The actor had to work hard on gaining that lost 30 pounds and then adding another 15 to it. He even had to let go of his girlfriend as he was busy all the time in the gym.