Originally Posted by JB
But he had terrific leg drive and could push the pile when he needed a yard
Sure and so do Ray Rice, MJD, so did Payton. That kind of leg drive is not unique to people over 225 lbs either. I'd even argue what you typically see in 230+ RBs are taller guys with correspondingly longer legs and that shorter legs are better at that kind of leg drive just like huge wingspan guys like LTs struggle in the 225 lb lift at the combine.
As an aside, after the Cowboys 1st SB win Aikman, Irwin and Emmitt had a competition to get to the lowest body fat and Emmitt lost a few lbs. I can't remember which was which but Irwin and Emmitt got to 5 and 7% with Aikman bringing up the rear at 10%.