They don't use any mind altering substances. That's what their talking about. They look at it like the "high" they get from working out the way they do is better than that of pot/alc.
A couple of my friends and I do this type of stuff almost every day(except we still drink our faces off occasionally). It takes a looooong time to get on their level but it doesn't take long to notice a HUGE improvement in strength and flexibility.
Check this guy out. Hands down I'd be willing to bet this guy is one of the most physically fit people in the world.