HELP! What can I do to stop my nipples from bleeding on long runs (over 10 miles). I have no trouble on my training runs of up to 10 miles but anyhing over this and I'm in trouble. I've tried vasaline, plasters, corn things(?!) to knoe affect - it doesn't seen to matter what top I wear either - some advise please.....(Matthew - first time marathoner at NYM 7 November)