Agree, it is quite remarkable. Those runners obviously train hard but also have some genetic adaptions that help them.on running (not posted in support of my point here, just fascinating a tribe comprised of 0.06% of the worlds population dominates a sport)
View: http://www.npr.org/sections/parallels/2013/11/01/241895965/how-one-kenyan-tribe-produces-the-worlds-best-runners