Henry Cavill (Theseus) refused all assistance from the make-up and visual effects departments to achieve his eight-pack for the movie. He told them, "I do not want you to draw abs on me." Cavill said it was "a pride thing" for him, and he "actually wanted to have that body for real, and show it in the film."
Henry Cavill did not do any weight training for his preparation for this movie. His physique was achieved through a tabata-style training regiment, consisting of only body weight exercises. This training methodology was chosen, because the goal was to not put on much mass, but to develop a very lean, highly defined physique.
When the project was set up, the financing was still being negotiated, even though filming was set to begin just six months down the line. Henry Cavill began his intense training regimen for this movie right away, even though the producers said that they did not have money for the trainers yet. Cavill elected to pay the trainers out of his own pocket, until funding could be acquired, and he continued training. Six months later, as the filming date approached, the producers told him the financing had fallen through, and he should stop training, so Cavill stopped his physical prep then. Another six months later, the producers told him they had now acquired alternate financing and he should start training again, and so Cavill set out to achieve the required physique for the character a second time, only for the financing to fell through yet again. The producers again asked him to stop for the moment. After some time, the producers finally acquired concrete financing, and when they called Cavill the third time to tell him to start his training, they realized that he had not stopped since the last time. He had maintained his physique and was ready to start filming. They said that Cavill effectively ended up building his body three times over three separate six month periods for this role before filming finally began, and they saw this as the best demonstration of his commitment to the role and the movie.
Henry Cavill (Theseus) noted that there was a healthy competition on-set amongst all of the male actors, as all of them had to appear shirtless, and all wanted to look his best in front of the camera. He said that they would have friendly "best abs contests" to determine "who had the best abs". Luke Evans (Zeus) said that Cavill was definitely the one to beat.
Director Tarsem Singh told Henry Cavill after their first meeting that if he got the role of Theseus, he would have to develop an "eight pack", not a "six pack". He could have very little body fat on his body because his wardrobe would be very revealing. Cavill trained for six months and developed his abdominal muscles into a full "eight pack", which was then displayed throughout the movie in numerous shirtless scenes. He brought down his body fat percentage to six percent, which he subsequently maintained throughout the shoot.
Henry Cavill, who is naturally hairy, had to shave his torso for this movie. He said that shaving had its advantages, as he was able to see all of the muscle definition that he had achieved for the role.
The filmmakers stated that they chose to change many aspects of the ancient Greek stories to reflect the fact that the Greeks often revised their mythology to conform to new ideas and knowledge. One aspect of this movie, which is specifically addressed in the special features, is having Zeus (Luke Evans) and Poseidon (Kellan Lutz) appear as young men rather than old men.
Henry Cavill said he felt very stressed out leading up to the filming of his shirtless scenes for the movie. He would wake up every morning and look into the mirror and think "Can I still see the veins in my abs?" He said he did look good enough, but felt a lot of pressure because he wanted to completely deliver on the shape for which Director Tarsem Singh had asked (a full eight-pack of abs).
There was a big breakout of chest acne amongst the male cast members, due to the waxing of their chests for the shirtless scenes. Stephen Dorff (Stavros) said he preferred to use an electric razor instead.
In one scene, Theseus consecutively fires four arrows, which then go on to hit their respective targets simultaneously. This is a one-to-one re-creation of a scene in House of Flying Daggers (2004), directed by Zhang Yimou.
When he was editing, Tarsem Singh set his action to a guide track from The Pillars of the Earth (2010). He felt that the score seemed to blend in very well with his vision, so when it came to choosing a composer for this movie, Trevor Morris was the natural choice.
The castration of Lysander (Joseph Morgan) was not meant purely for shock or even dark humor, but to symbolize his lack of courage and virility. King Hyperion (Mickey Rourke) chastised Lysander for being a coward and decided to make it as literal as possible by taking away his ability to procreate, thus further reinforcing that he is not a real man.
Despite Frida Pinto's use of a body double for the sex scene, the scene still caused some controversy in Pinto's native India, where such scenes are considered taboo. She laughed off the criticism as she is still relatively unknown in India, choosing instead to work on projects in the US and Europe.
When Theseus touches the Epirus Bow pretending to shoot an arrow, an arrow of light magically appears. It's a nod to Dungeons & Dragons (1983). In it, Hank was turned into the archer by Dungeon Master, giving him an arrow which shoots light arrows that appear magically as many times as the archer wants.
The trivia items below may give away important plot points.
The story is very loosely based on Greek mythology, combining elements of various myths. In the myths, Theseus was King of Athens (the capital of Greece) and (in some versions) a son of Poseidon (Greek god of sea and Zeus' brother), although his legal father was King Aegeus of Athens (namesake of the Aegean Sea). Theseus killed the Minotaur (a creature with the body of a man and a head of a bull imprisoned in a labyrinth, depicted here as a man with a helmet made of wires and horns) with the help of Princess Ariadne, whom he later married. King Hyperion is from a different myth, and was the name of one of the twelve Titans. There were only twelve Titans in the myths, and they were immortal and unkillable. There was a war in the heavens, and the Titans lost. Zeus then threw them into Tartarus, which is represented as a mountain in this movie, but in the old myths, was a cave at the center of the Earth with minor similarities to Hell, to be imprisoned for all eternity. Epirus Bow doesn't exist in any mythology, but it might be inspired by the bow of Heracles, a.k.a. Hercules, which was used by the Greeks to defeat Troy in the great war. (Epirus was a Greek kingdom in what is now Albania, and was home to King Pyrrhus of "pyrrhic victory" fame.) The movie's version of Theseus might be partially inspired by Heracles, a.k.a. Hercules, a son of Zeus who was the only hero to ascend to Olympus to rule with the Gods. Phaedra was the sister of Princess Ariadne, and the second wife to Theseus. She was not a seer. Acamas was the son of Phaedra and Theseus, but wasn't a seer either. Theseus was murdered in his old age, but not in a battle, and he did not ascend. Hoplite was the ancient Greek title for soldiers in ancient Greek states. Heraklion is a capital of the Greek island of Crete, and there were never any military formations with that title. In the Theseus story, Crete had its capital at Knossos, and its ruler was the cruel King Minos (father of Ariadne and Phaedra), who was the basis for this movie's Hyperion. Sibyl was the ancient Roman title for prophetesses. There were twelve Olympian gods and goddesses, and they were immortal and unkillable as well.