Bryon Powell has written Relentless Forward Progress, the first how-to manual for aspiring ultrarunners. Powell covers every aspect of training for and racing ultra distances. Along the way, more than a dozen elites and experts, including Geoff Roes, Krissy Moehl, Michael Wardian, Dave Mackey, and David Horton, provide invaluable advice on running ultramarathons. By its conclusion, this encyclopedic volume prepares runners for going farther than they have ever gone before and, in the process, sh...