That heart-pumping, give-it-your-all feeling is one of the reasons many of us run in the first place. And a ramped-up heart rate during any type of exercise is not only normal, it's necessary. But ...

Sally Kipyego, marathoner and Olympic silver medalist in the 10,000 meters, can hold a sub-5:00 minute pace in the 10K. Achieving that requires Kipyego to log plenty of hard track sessions and tempo ...

Add Yahoo as a preferred source to see more of our stories on Google. Want to become immortal? Get on a treadmill. Set it to an easy pace. Then do your typical one-hour run. Everyone you care about ...