It was the way things were done until recently. We had triple sessions in the late 60s and early 70s, with little water.. Live hitting at 2 of the 3 sessions. If you were hurt, you rarely got an Xray, let alone a CAT scan or MRI. You got maybe some hot balm put on and told to walk it off. If you were too hurt to practice, you often risked losing your starting position. A concussion then was called getting your bell rung . Guys who stood on the sidelines hurt during practice were called pussies.
Now imagine playing in the 50s. What Bryant did was no different than his peers, except he won more. A whole lot more. Accepted practices have changed, not only in football, but in life.