I've found that when I've run, for say two hours, I have terrible chafing just below both armpits, to the point where I have bled. It's not so much my clothes (I've worn many different running tops) but it doesn't make any difference. At the moment I'm simply applying vaseline all the time and also Germoline to try and heal as much as possible before the next run. Trying to change my running technique to more like the style of Paula Radcliffe (arms out to the side) but it feels quite unnatural. Any bright ideas?