Whenever I run even the smallest distance in the mornings for required track at school, for some reason, I get really nauseous, and suddenly I get cold sweats, my friends tell me I get really pale, and I always feel dizzy! I cant run very fast and get tired after 30-45 seconds! I cant even run 1/16th of a mile! I am healthy in body weight and everything! What's wrong with me? (does it help if I say I am on my menstrual cycle?) Also, how can i prevent this all from happening??