Sport-related migranes

I have been getting migraines for about 18 months now, and they only occur after playing or training for soccer. They have been more frequent in the last three months ( I have gotten about seven in total) but I was wondering if anyone else has had experiences with a sport-related or exertion-related migraine. They have all occurred after my running (anywhere from 20 to 40 minutes afterwards) and always start with very blurred vision, so much so that I have a hard time walking, and then quickly move on to a throbbing pain on top of my head an behind my eyes. I also become nauseated and begin throwing up. I also hydrate properly so I know this is not a trigger. Does anyone have any ideas about what the triggers could be?

If you look on the thread about over heating you will see that many of us seem to find this triggers migraines. That could potentially be the problem.

http://www.headachedrugs.com/archives/exercise_induced.html

Great article.

Just my personal experience. If I exercise so hard that (some of) my muscles ache from lack of oxygen, I tend to get a migraine afterwards. If I take it a bit more easy, and do not create this oxygen deprivation I can go pretty much forever and have mo problems.

I realize that this may not be possible in soccer :-)