Smokin' Joe Frazier was an Olympic and World Champion, he defeated Muhammad Ali in 1971 in what was called the "Fight of the Century."
This what Joe said about training...
“You can map out a fight plan or a life plan, but when the action starts you are down to reflexes. That’s where your road work shows. If you cheated on that in the dark of the morning, you’re getting found out under the bright lights.”