Writing from both the cutting edge of scientific discovery and the front-lines of elite athletic performance, National Magazine Award-winning science journalist Alex Hutchinson presents a revolutionary account of the dynamic and controversial new science of endurance.

In 80/20 Running, respected running and fitness expert Matt Fitzgerald introduced his revolutionary training program and explained why doing 80 percent of runs at a lower intensity and just 20 percent at a higher intensity is the best way for runners at all levels - as well as cyclists, triathletes, and even weight-loss seekers - to improve their performance. Now, in this eye-opening follow-up, Fitzgerald teams with Olympic coach Ben Rosario to expand and update the 80/20 program to include ultramarathon training and such popular developments as the use of power meters.

David Clark is a formerly obese alcoholic and fast food junkie who found a new life in running. Now, 13 years after his transformation, he shares his inspiring story of taking running to the extreme edge of his physical and spiritual breaking points. Having run more than a hundred races, including the Leadville 100-Mile Trail Run and the Hardrock 100, David has achieved unimaginable success in the ultramarathon world, considering his humble start.

There is a new revolution happening in sports as more and more athletes are basing their success on this game-changing combination: health, nutrition, training, recovery, and mindset. Unfortunately, the evidence-based techniques that the expert PhDs, academic institutions, and professional performance staffs follow can be in stark contrast to what many athletes actually practice. When combined with the noise of social media, old-school traditions, and bro-science, it can be difficult to separate fact from fiction.

Long distance running is much like any other fitness training. If you want to improve, you need a good plan that has a progressive nature. If you are new to this game, you need a solid foundation to build on. Having a running program is not the only thing that you need. Sound advice and running tips should be taken from someone who has "walked the walk", or in this case, "ran the run".