Originally Posted by apollack
Today Sullivan would be a heavyweight, no doubt, and he'd knock most of these guys out without problem. He mostly weighed 200-230 pounds, at his best was in the low 200s, and only got below that for fights to the finish where he might have to fight for 3 hours, so he intentionally got down to be efficient, and also when you are running 10-20 miles a day and training for 2 plus hours a day, you tend to lose weight. If the lard asses fighting today did the same, they would slim down too. Also, if Sully had the nutrition and weight training they have today, he'd be a rock solid 230 with no problem.
With his rather dissolute training practices, I could see Sullivan going the same way as many modern contenders in trying to substitute weights and a little sparring for real training.