You can't look like you sling down 9,000 calories a day and consider yours a "focused" and "determined" HW champion of the world. Remember people ripped AJ "Boxing is not a bodybuilding contest". Yea but its not an eating contest, neither. Ruiz' lack of discipline, his terrible lack of professionalism create an unnecessary headwind for him. He's an idiot to look like that as a pro boxer who could earn tens of millions in the next couple years.
One very big difference between these two scenarios. Lewis had to make one adjustment to reverse his loss and he claimed he knew what it was after he left the ring following his loss. Joshua has to make a whole bunch to account for all the deficiencies which showed up in his defeat. That, or hope Ruiz has got comfy and lost his ambition. A one-punch KO you can come to terms with - file it under 'one-off' and move on. Being totally dismantled by a short, fat bloke; that's tough to come back from...