Arnold Schwarzenegger's Training Program for Muscle Mass Who knows how to gain lean muscle mass better than Bodybuilding King Arnold Schwarzenegger? Probably a few people or we can say almost no one. Arnold Schwarzenegger is Bodybuilding, he is Lean Muscle Mass and Strength. We can almost say that he popularized Bodybuilding and Fitness. One of the biggest icons of bodybuilding was never always big you must know, he was also skinny young kid, but that was before he was 15.  Take a look how big and aesthetic was Arnold when he won Bodybuilding Tournament in Germany when he was 15: \ He was huge back then and he was huge all his life and he actually still is. So, do you know what program for muscle mass gain Arnold recommend? Here it is: Monday - Chest and Back: Exercises Rep Range Sets Bench Press 8-12 3-4 Incline Dumbbell Press 8-12 3-4 Dumbbell F...