Primal Endurance shakes up the status quo and challenges the overly stressful, ineffective conventional approach to endurance training. While marathons and triathlons are wildly popular and bring much gratification and camaraderie to the participants, the majority of athletes are too slow, continually tired, and carry too much body fat respective to the time they devote to training. The prevailing "chronic cardio" approach promotes carbohydrate dependency, overly stressful lifestyle patterns, and ultimately burnout.

Mark Sisson, author of the 2009 bestseller, The...