Sisu

Definition: http://www.finlandia.edu/sisu-our-finnish-identity.html

Wikipedia: http://en.wikipedia.org/wiki/Sisu

Article from Runningtimes.com: http://www.runnersworld.com/elite-runners/finding-sisu?page=single

Article from Washingtonpost.com: http://www.washingtonpost.com/wp-dyn/content/article/2006/03/22/AR2006032201943.html