Breaking stones with heads or hands, tearing phone books, performing amazing feats of strength and the like go waaaaaay back. The earliest accounts of martial art tricks/stunts I recall go back to the days of the Roman gladiators.
Today it’s shaolin monks, less recently “no-touch” knockouts, a couple decades ago it was the “unbendable arm” and other ki tricks; a hundred years ago it was the jujutsu invaders entering the west doing pole-on-neck stunts. Physical culturists performed the same feats and you could find carnies, wrestlers, other martial artists, and strong men (and women) all performing similar feats at different places and times in history. The line between the categories was often blurred with some demonstrators seeming to hit all of those descriptions.
I like the following site because it shows how some of the popular tricks are performed and that there is no mystical basis behind them. Some of these techniques may require strength, but, just like good martial arts, proper technique is a strength magnifier, and they show you the techniques that make the stunts possible.
Included are ways to break bricks, bottles, roll up frying pans, resist multiple people, fake powerful punches, tear phone books and other tricks of the trade. I also like that they include some elements from the CQC/CQB/WWII combatives field, such as putting someone in the grapevine and escaping the grapevine yourself. For those unfamiliar, the grapevine was a method shown by Fairbairn to lock a man to a small tree or pole by arranging his legs in a certain way so that he could not escape unassisted.
The site is Kung Fu Do (formerly Bad Kung Fu) and I urge you to check it out if that’s the sorta thing you’re into. The site wasn’t laid out all that well in the past, and you had to poke around a bit, but it looks easier to navigate these days. As for me, I couldn’t get enough!