So I'm an out of shape bastard. I haven't ran/worked out in a LONG time. Well, the other day I decided to get my ass on the treadmill. I started out with a fast walk and proceeded into jogging. Not to far in the muscles on the outer edge of both of my legs got really tight to the point that I couldn't keep going. What the hell was that? It hurt like a mofo, and while I wanted to keep going I had to stop. Any ideas to keep this from happening?