I usually expierence headaches after runs for two reasons. One, if I change tempuratures quicky after, like running outside where it's cold and then going straight inside. Also, sometimes I will clench my jaw when running, so I conciously try to keep my mouth slightly open. Hope that helps!

Thank you very much for the reply! :-)

I agree, but it could also be from dehydration! I stay hydrated by using nuun :)

Great advice, thank you very much!

It's good to push yourself, and headaches are common when you put a lot of strain on your body. Like See Bri said, just make sure you stay hydrated. You definitely do not want to get to the point where you feel light-headed. That can be especially dangerous when running on a treadmill. 

 Keep pushing yourself and your body should get used to the stress you put on it when you run. If you've been a runner for a while and are getting headaches, you might want to tone it down a notch. Otherwise, keep up the good work! :)  

Thank you! :-)

STOP! Headaches are not common!! Ask your doctor and please stay HYDRATED! What a oxycotton world you people live in where headaches are common! The human body can operate without drugs, pain is your body saying hey I have a problem...that is unless you have purposly stressed muscle tissue but that does not hurt your brain.

Thank you!

I get headaches or lightheaded sometimes after a long run. Proper hydration and fueling is so important. I also usually eat protein pretty quickly, and I feel better. I don't eat snacks during a run that some runners like (just haven't gotten into that), so I sometimes feel a little sick from so my fluid. Something solid usually settles my head and stomach right down.