Matt Bomer knows what it takes to change his body—whether that's dropping 40 pounds for his role in The Normal Heart, packing on slabs of muscle for both Magic Mike films or—for one of his latest challenges—flashing between a lean-but-ripped vampire to a strung-out heroin addict in American Horror Story: Hotel. Here, in this exclusive behind-the-scenes video from his MEN'S FITNESS cover shoot, he opens up about the discipline all that takes, plus his go-to workout, what it's like to work with Lady Gaga, and more.
