He looks in great shape and doesnt look 61. I bet alot of other boxers want to know what his secret is, also only one KO loss in his career!!
He is unique - one out of millions. You can“t set a standard using him as an example. He may be a kind of gym-addict - needing to excercise every day. Old fighters on a comeback usually have to lose a lot of weight, regain musclepower - and as result get tapped of energy.