Scott Adkins's character, King Amphitryon, is seen at two different ages in the film, younger and older, and Adkins created two different looks for the character. He said he wanted to look extremely "lean and ripped" for the younger scenes, showing highly defined eight-pack abs in a shirtless scene, as compared to very "muscular and bulky" for the older scenes, where he just had to show his biceps in sleeveless costumes. He said for the younger scenes, he ate very carefully and trained a lot to achieve the ultra-cut look but for the older scenes, he trained just as hard but ate what he wanted because the focus was on size and not muscle definition, and he did not have a shirtless scene anymore.
Director Renny Harlin required all of the male actors to shave their legs and torsos. The film was shot natively in 3-D, and he said that body hair stuck out when shot with stereoscopic cameras.
This was Kellan Lutz's second Greek mythology movie. Lutz portrayed Hercules' uncle, Poseidon, in Immortals (2011).
Kellan Lutz said his co-star Scott Adkins had the body of a god and that his physique was so great, it looked green-screened. He also said it "did not make his Hercules character look too well."
Due to the heavy armor worn by his character throughout the film, Johnathon Schaech was bitterly disappointed that he was unable appear shirtless in the film. He had been following a punishing bodybuilding and dieting regime to prepare for the role.