Michael Crawley is the author of the brilliant new book on Ethiopian running, Out of Thin Air. A 2:20 marathon runner and an anthropologist, Michael spent 15 months embedded with a group of top Ethiopian athletes, running with them, eating their food and sleeping in the lodgings. Out of Thin Air is a fascinating exploration of one of the world's most incredible, yet largely unknown, sporting cultures. Michael is on Twitter @mphcrawley. Produced by @IAmTheHow. Music: Starfrosch.