He could be quicker but the squat, muscular build of a middleweight suggests he's never going to have Thierry Henry's pace. However, what he does have is formidable upper body strength. He may not be quick enough to outrun a defender like William Gallas, but if he starts in front he's strong enough to stay there.
He's a bit like Diego Maradona in that his physique means he's able to withstand challenges from the side. He can ride all but the best tackles and once running under a full head of steam, with the ball at his feet, he's very difficult to dispossess.