Boxers' Training Styles: Trade Secrets?

I’m guessing the coach and staff of boxers like Ali, Frazier, Tyson, Mayweather, etc., kept a sharp lid on just how their boxes trained. Only long after will they disclose. With Ali, he admits to doing lots of sit-ups and curls to toughen his body. Frazier said road works was vital if he was to keep bobbing between head and waist level for 15 rounds. Tyson’s revelation was that he never took weekends off during training, and his training was more on forms (boxing techniques) than basic (strength, speed, stamina.)

Just how much can one’s training be a real winning edge?