Just like the rest of his workout, Henry Cavill’s dumbbell curls were tailored to him and his specific needs. The actor had to have forearms that were capable of taming big, strong horses for extended periods of time (Geralt is an experienced rider and goes through many horses, all of whom he names Roach, in the source material). Dave Rienzi had his client doing dumbbell curls alternating from a static hold, which helped sculpt those huge forearms you see in the show. “With horse riding this can make a difference,” Cavill said during his Train Like a Celebrity video. “If you have a particularly powerful horse — whether it be a stallion or anything else — which is really, really going for it, to have that necessary heave back on the bit, it does help.”
Having muscular endurance in the forearms was also essential for the show’s complicated swordplay. According to Cavill, just hanging onto his sword is enough of a challenge come the end of a long day of shooting. “When you’re holding a sword, the first few takes are fine,” the Brit explained. “When you’re into take 16 of the day and you’re doing very complex movements with your wrist, your forearm does start to die, and you end up throwing swords across the room rather than making a swing.” Luckily, Cavill put the work in, and (as far as we know) nobody was impaled by a flying sword.