No pain, no gain – this cliché is especially true for actors suiting up as on-screen superheroes. Many stars have gone the extra mile to fully commit to their character. They’ve hit the gym and packed on the pounds in order to take on the persona of their on-screen superhero. Just like many of their superhero alter egos, these stars alter their bodies and go from boy next door to a buff & bulked up leading man – but it doesn’t come without hard work. Whether they’re shedding pounds, toning up or gaining muscle, AccessHollywood.com counts down the Top 10 stars that have undergone massive body transformations for their super-powered roles!