=Relentless Forward Progress=
[[File:Relentless-Forward-Progress.jpg|right|thumb|200px|The cover of [http://www.amazon.com/Relentless-Forward-Progress-Running-Ultramarathons/dp/1891369903 Relentless Forward Progress].]]
Byron Bryon Powell's book "Relentless Forward Progress", subtitled "a guide to running ultramarathons" is one of the first books that focuses on providing systematic advice on ultramarathon running. The book includes a number of training plans that are mentioned above, but also includes a lot of breadth and depth. While I may not agree with all of the advice, it's a well written book that is well worth reading interested in running ultramarathons. I particularly like the way that Byron Bryon has asked many authors to write up sections of the book to give their perspective. I'm especially impressed the way Byron Bryon gave two different authors the chance to put forward their opposing views on the role of speedwork in ultramarathon running.