I recently finished reading Max Brooks’ excellent World War Z: An Oral History of the Zombie War, and in it Brooks makes it clear that zombies move slow - real, real, slow. Indeed, up until the 2004 remake of Dawn of the Dead, there were no fast or quick zombies outside of the Return of the Living Dead series. Now 28 Days Later is often credited with creating the hyper-fast zombie, but this is not the case as 1) the creatures in 28 Days are not dead but infected, and 2) they do not eat flesh and/or brains. The idea of hyper-fast infected was adapted by Zack Snyder for the remake, and really it is with him that this break in the Romero zombie canon lies - one continued by Charlie Brooker in Dead Set.
However, there is one example of fast-moving zombies in Romero’s work. It’s from the helicopter scene in Dawn of the Dead (1978). The zombies in question are children, not exactly the easiest to direct, but still, they don’t move as Karen Cooper in Night of the Living Dead.
By the way, I realise that although we’re talking about zombies, I’m the one who has no life.