Someone scanned a book from 1952 called, How to Perform Strong Man Stunts. This is the kind of thing you could buy from the end pages of comic books. This throwback has the best intro:

One of the truest statements ever made is, “All the World Loves a Strong Man.” Every man, woman and child admires strength, and there is not a man who does not crave it. To be stronger than your friends is to be looked upon as a natural leader, and an invincible defender. Strength is the biggest hallmark of manhood. It demonstrates true he-man masculinity.