Add Yahoo as a preferred source to see more of our stories on Google. WHEN I FIRST started running long distances, I had one goal: go as fast as I could for as long as I could. I ran the same 5k route ...

WHEN I FIRST started running long distances, I had one goal: go as fast as I could for as long as I could. I ran the same 5k route a few times a week, always aiming to go faster. Every time out needed ...

Maybe you’re lucky enough to have felt a runner’s high, when the breeze, sun, and your mood make it clear that humans were born to run. On the other hand, maybe you’ve also logged time in waiting ...