Hello.. I used to have push ups with 10-25 repetitions. But, one day I want to reached more than 25, so I pushed my body more and accidentally lifted my head, so my head was in the looking-forward position. By the time i changed the position of my head I got a heavy headache. It felt like my head being stabbed and throbbed. It happened approximately 20 minutes. The next day i did the push ups again, and my headache occurred again (i didn't even reach 5)... any ideas? Thank you before