I was a 46.0 guy. I always trained with the CC team during the summer in my home town as my school was on quarters and started a whole month behind. With that one month of CC training, running a 4:50 was pretty easy. I'm certainly no Usain Bolt and I'm sure he could do much better than that if he wanted to. I'm sure he could easily break the 400m record if he wanted to as well, but that is a whole different discussion.