The Differences Between Fast and Slow Fibers in Athletic Performance

In our muscles we have two essentially two types of fibers, fast switch and slow switch. We all have a mixture of both, but we have different proportions. Those sprinters would tend to have much more fast switch fibers than someone like myself that runs long distances. So does that mean that you saying bolt would be rubbish in marathons then? I think I was sort of slow over short distances. Yeah, actually slow over long distances as well. But anyway, why is that?