There is the theory about the mind/body connection and how visualization has been used in workouts. Thought it doesn't involve shouting like the bro is doing. It's a deeper mental process. Some Olympic level athletes use this process. Olympic and Pl'ers also...where they see, in their minds eye, their lift becoming successful. Russia and other Eastern European country's pioneered this idea. Some versions involve actually getting mad at a weight, a enemy to your lifting success, as Pl'ers, and others, are prone to do.
Self hypnosis has also been used, though not quite the same as the visualization method. In clinics, the hypnosis thing does not always work the way you would think it would.
Arnold was said to imagine his biceps becoming mountains when he worked them. Zane also. I always believed that working out was a mental process, just as well as a physical one. And there are the stories of a grandmother who picks up the end on a heavy car, that has trapped her grandchild, etc, under it. This without a moments thought before hand. And the grandmother is not unusually sore the days after the lift. .
The mind/body connection, still amajor mystery to science. Must be a good reason for all that gray matter in the brain, yet really not fully understood..Good Luck.