Endurance

kingkong123

Bear Grylls Interview - http://www.runnersworld.com/article/0,7120,s6-243-544--13910-1-1-2,00.html

I read you did a lot of running to get ready for climbing Mt. Everest. What was your routine?

...There's no magic to running far or climbing Everest. Endurance is mental strength. It's all about heart. It's about having balls.