I thought this was hilarious, facetious, yet worth thinking about – if you are into running marathons competitively, the key to winning is to develop skinny-fat (or the equivalent of ‘ugly asses’). By making your body super efficient, you learn to burn calories slowly. Rather than having muscle mass, aim for lean mass. That said, this is more interesting food for thought than something I would encourage. The downside is you over-optimize: your body is made for conserving energy across ultra-long distances, but not much more. More at
http://barefootrunninguniversity.com/2013/08/02/ultrarunners-boost-endurance-by-slowing-metabolism-the-skinny-fat-phenomenon/
.