Yes, I know of after-exercise headaches but this is different. I'm really not active but I do have times where I use the treadmill to shed off a few pounds. Last week, I started up the routine and noticed that I got a pounding headache which lasted for about 1-2 minutes and then completely went away. Now, this usually happens when I run on the tredmill. It even happens if I run briskly to the door or something. Is this something really serious? Btw, I'm a person that really never gets headaches, I've never had a problem with them (in general I meant).