I used to run when I was younger, but gave up about six years ago when I entered high school, when suddenly it was a draining and painful for me to go for endurance...
I recently took jogging outdoors back up. I can't go very far at all-- generally, I'll go for a mile on the pavement, two at most. (I actually find it easier to work out in the gym... I have no problem doing the elliptical for about an hour, finishing with 5 or 6 miles under my belt). For the longest time, I've been trying to figure out what it is about running that got me. My legs are strong, so it wasn't that... While my lungs aren't the best, they manage to feel alright after I keep persisting and fall into my rhythm.
But I realized the real pain from running, once my body has gotten used to the beat of the movment, remains in the veins/arteries (I'm no doctor) in my neck. They throb and ache insanely when I'm running.
I know my family on my mom's side has a serious history of high blood pressure and heart disease... I try to consciously eat with cardiovascular health in mind, but is this an early warning sign?
I always recommend that people speak to medical professionals for medical issues. It's good to at least get the all clear for you own piece of mind.