T'Challa isn't Boseman's first physically demanding role. In 2013, he portrayed Jackie Robinson—the first African American to compete in Major League Baseball (MLB)—in the biographical drama 42. As well as capturing Robinson's off-field contribution to the civil rights movement, Boseman needed to appear authentically athletic for scenes on the field.
Due to the nature of the game, professionals mix strength, speed and explosive movements, required for throwing or striking the ball at top speeds. To prepare, Boseman trained twice a day for three and a half months, following the same techniques as the pros. In an interview with GQ, he referred to the sessions as "madness" due to the strain such activity places on the body. "Their training," he pointed out, "is all about strengthening the tendons around the bone and the joint so you don't tear the muscles from the bones." Yikes.
Boseman had the opportunity to put the training to the test when recapturing Robinson stealing base by sprinting from first to second. Doing this once is tiring enough, but director Brian Helgeland needed to shoot multiple times for different frame rates. Naturally with fast-paced action, things go wrong. As a result, in scorching heat, Boseman ended up shooting the scene a tendon-popping 50 times. As he later admitted, "I definitely had some moments stealing the bases when my body was like, 'that's it for the day'!"