Excellent series of 9 videos on utube demonstrating practical and extremely tough physical and mental conditioning. Some of the most pragmatic obstacle course training I have seen. Suspect we wouldn't be allow to run these today, but then again they were training for combat with peer competitors and the outcome was uncertain. You can get the jest of it in the first three videos, but recommend looking at video 9 also.

https://www.youtube.com/watch?v=98G_xIPSgXA