Acting is an inherently physical profession. A large part of the job deals with memorizing lines, tapping into extreme emotions, and bringing complex stories to life, but there's no denying that much of a thespian's life is spent physically embodying a wide range of characters. To convincingly portray another person, many actors spend a great deal of time perfecting the mannerisms, speech patterns, and physical charm of their roles, hoping to persuade the audience to suspend their disbelief and embrace the on-screen fantasy.

Occasionally, this transformation is as simple as a costume or a well-made wig. Other roles require a total body transformation, causing actors to spend months in intense training to build a physical framework that will allow them to fully tell the story. Christian Bale is known for these chameleon-like transformations and seems to remake his body for every new role he takes on. Though he has become...