About the Author

Jim Gourley is an endurance sports journalist whose work appears in various publications and is regularly featured on the website of Foreign Policy Magazine. He is the author of Faster: Demystifying the Science of Triathlon Speed. He lives in El Paso, Texas. Hillary Biscay is the Ultraman World Champion and one of the most prolific iron-distance competitors in the professional women's racing circuit, having completed over 60 Ironman triathlons. She lives in Tucson, Arizona.