I wish to express my heartfelt thanks to the following men and women who made this book both possible and better than I could have made it alone: Iris Bass, Kevin Beck, Rochelle Cuff, Desiree Davila, Christine Dore, Fred Dufner, Anthony Famiglietti, Nataki Fitzgerald, Sean Fitzgerald, Shalane Flanagan, Mario Fraioli, Gabriel Gastelum, Brett Gotcher, Kara Goucher, Ryan Hall, Kevin Hanover, John Heusner, Libbie Hickman, Asker Jeukendrup, Scott Jurek, Deena Kastor, Meb Keflezighi, Linda Konner, Joe Lemel, Annie Lenth, Irit Levy, David Morken, Kim Mueller, Dave Munger, T.J. Murphy, Tim Noakes, Kate Percy, Robert Portman, Ben Rapoport, Kristian Rauhala, Pete Rea, Dathan Ritzenhein, Stephanie Rothstein, Jonathan Sainsbury, Mark Sands, Renée Sedliar, and Ross Tucker.