He bulked up on purpose. He had just come through a mauling type slugfest with Skelton the first time around. He discovered that he was the bigger puncher and that (without the fouls) he could handle Skelton easily.

He figured, quite reasonably, that if he bulked up, Skelton would not be able to push and maul him, and that he could then use his weight to lean on and bully Skelton, wearing him out by the middle rounds.

Tactical masterstroke by Skelton - come out and box and 'dance'. I never thought he could fight any other way than the all-out assaults we have seen so far!!!

Danny then could not think on his feet and could not stir himself to make a 'shit or bust' assault of his own - so he deserved to lose as he only wanted to survive by that point.