I was on the Science of Sport website and saw this video of an ultra-endurance runner attempting to break the world record ascent of Mt. Kilimanjaro (which he did in a little more than 5 hours). The total time it took him to get up and down this amazing mountain - all 19,340' - was 7 hours and 14 minutes. You can't imagine how difficult that is. It took the group that I went with (Feb. 2008) about 10 days - the shortest route via a travel group is 6 days - you need time to acclimate to the altitude. I have heard of people climbing it in three days but to run it in less time than you spend in the office is simply amazing - great job Kilian and good luck to Ross Tucker, PhD from the Science of Sport who is attempting to run Kilimanjaro barefoot.