Run Oregon invited Marc Larson to share his thoughts on the book Training Essentials for Ultrarunning by Jason Koop. Larson has run a few 50ks and is training for his first 50-miler (ORRC’s Autumn Leaves 50 Miler), and is at a place in his running where he can appreciate how slight changes in his training, nutrition, and mental preparedness can make an ultra more enjoyable. This book, available in paperback from VeloPress, covers these topics such…