This role was much more challenging for Arnold than I realized.

Injuries notwithstanding, stunt coordinator Terry Leonard confirms that not only did Schwarzenegger, Bergman and Lopez perform most of their own stunts, they did so admirably and with great stoicism. Schwarzenegger recalls that Milius' standard morale-boosting refrain (in keeping with his personal philosophy) was that physical pain was temporary, but the resulting film would be permanent. The trio trained extensively with black belt and expert swordsman Kiyoshi Yamazaki who forced them to practice routines over a dozen times before allowing them to step in front of a camera.

The physical aspect of the performances was not the sole focus of attention. Schwarzenegger had considerable trouble minimizing his thick Austrian accent and delivering his lines with the required effectiveness. He and Milius figured they could do little about the accent, but proceeded to work hard on the specificities of line delivery. They would retire to Milius' trailer every day before lunch and rehearse the longer monologues over and over, until Schwarzenegger could commit the suitable cadences and stresses to memory. By the time he delivered them on camera, he had rehearsed each speech forty or fifty times. Schwarzenegger also received some help from stage actor James Earl Jones, who demonstrated line reading options for him in return for workout tips.