While looking through a stack of Wall Street Journals the other day, I ran across two articles that I found interestingly enough to read in their entirety. One is on adventure racing and the other is on ultramarathon running.
I figure that cyclists are probably aware of these disciplines (especially the first), and if not, then maybe you will enjoy reading about them.
My wife and I used to run, but no longer. But her exercise regimen is more diverse than mine. She has classes at the Meyer Center and works out on a regular basis on their machines. I just ride and try not to bend my elbow too much!