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.

Isolated by Mexico's deadly Copper Canyons, the blissful Tarahumara Indians have honed the ability to run hundreds of miles without rest or injury. In a riveting narrative, award-winning journalist and often-injured runner Christopher McDougall sets out to discover their secrets. In the process, he takes his readers from science labs at Harvard to the sun-baked valleys and freezing peaks across North America, where ever-growing numbers of ultra-runners are pushing their bodies to the limit.

The ultimate endurance athlete, Marshall Ulrich has run more than 100 foot races averaging over 100 miles each, completed 12 expedition-length adventure races, and ascended the seven summits - including Mount Everest. Yet, his run from California to New York - the equivalent of running two marathons and a 10k every day for nearly two months straight - proved to be his most challenging effort yet. In Running on Empty, he shares the gritty backstory of his run and the excruciating punishments he endured on the road.

In 2017, world-class ultrarunner Hillary Allen was at the top of her sport - and it felt like she was running on top of the world as she competed in Norway's Tromsø Skyrace. Allen was nearly halfway through the 50-kilometer race when she fell 150 feet off an exposed ridge, fracturing her back and breaking multiple ribs, both feet, and both of her lower arms. Beginning with the dramatic story of her accident and rescue, Out and Back: A Runner's Story of Survival Against All Odds recounts Allen's fight to return to the life she loves.

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.