I used to teach a form of this to my high school runners in the late 1980’s. The so-called “iron skin” [about 25 seconds into this video of Yi Long….not a Shaolin monk, just practices Shaolin Kung Fu].
Didn’t have them hit me.Just had a couple of them give me their best “indian rope burn” on my forearms, or have them stomp on my foot..The purpose being to show that they can use their brain to dramatically reduce the intensity of incoming pain signals to the brain, and absorb whatever is being inflicted upon them.
Something similar can be done during a distance event race in track and cross-country..They had a good time trying to inflict pain on their coach as payback for some of the workouts I subjected them to.