The first African American heavyweight boxing Champ Jack Johnson certainly earned his title inside the ring and out. When he did finally get his shot he had lost only two of his previous 63 fights going back almost a decade prior.
As far as preparation for the ring, Johnson’s condition bears the unmistakable mark of physical training and the old photos from the training camps in his era certainly back it up.He threw the medicine ball performed calisthenics, jumped rope, chopped wood and generally engaged in exactly the kind of physical training he would have needed to in order to compete for (and Win!) the Heavyweight championship of the world.
The tale of the tape from the Johnson/Jeffries fight indicates that Johnson had a 7-7/8 inch wrist, 15-1/4 inch flexed forearm and 17-inch flexed upper arm all at a 210-pound bodyweight. You may not realize this but Jack Johnson also was a performing strongman after his boxing days were over and one of his favorite feats was the human chain.