Recently, at a football match between Sheffield United and Aston Villa, the Sheffield supporters were calling Adrian Littlejohn, one of their own players, 'black bastard' whenever he made a mistake. They called the white players by equally derogatory names.
In my experience racism does not disappear because you have reached the height of your sport. You are merely tolerated because of your achievement.
It appears that athletics is the most racially integrated sport in the world, but this is because it would be difficult to avoid picking the best performers and most of them are black.
I have found life in the area where I live very difficult because I am black. It was completely different when I was competing.