This morning at the start of pt we took off on our run at a dead sprint. About 300 yards later they had us do 50 elevated pushups. So I put my feet over the wall and began. At 35 I began to feel funny. At 40 i got a bit dizzy and at 45 I had to stop because it felt like the back of my brain was going to blow out of my head. It got somewhat better as the day went on but here I am 10 hours later and I can still feel a dull throbbing pain in the back of my head. What gives?