I think Hatton sets a good example in the ring...
Not such a good one outside of it

B-Hop and Mayweather live the lives of Monks outside the ring and are always in tip top condition.
Mayweather's has some starnge ways though, or so ive heard...

Im not so sure about Ouma though, its just as hard to sustain upperbody and head movement as it is to move your pitta patta hands.