I hit the back of my head about a month ago and almost immediately experienced extreme exhaustion and a chronic headache. Then I went snowboarding without a helmate...yes I know it was dumb. But I have had a headache for the whole month. About a week ago they've started to let up. I've had breaks between headaches! Well track season's starting up again and I was wondering when it's safe for me to participate. I like to pole vault, probably the most head-hitting-prone event =P