By the time he was starting, he was already at 247 lbs.
While his best time while he was a pro was around 4.68, I had never seen any power back that size have that kind of a quick burst, and get to top speed like he did. I still remember the Sugar Bowl, where he just blew by the vaunted 6th ranked rushing defense of the Florida Gators, that supposedly had a half dozen starters who could run a 4.5 or better, and seeing them hunched over, gasping for air towards the end.