Some of those exercises are tough, tough, tough. When I lived in Pasadena, one of my training partners was a Mexican guy who was like that. Until he stepped into the fight gym, he'd never been in a gym, never even lifted proper weights, but he was strong, strong, strong. He punched harder than some of the light heavyweights, and he would regularly supplex 250 lb guys. He was also sort of crazy, and for some reason, couldn't get the emotional discipline to take him to that next level, but he could easily have been a great fighter. Just goes to show that the guys at the top of the game aren't necessarily those who have the most natural talent, but are those who have a degree of natural talent, plus ridiculous work ethic.