Matt Hart is a freelance journalist whose writing covers sports science, human-powered adventure and exploration, performance-enhancing drugs, nutrition, and evolution. His work has appeared in The New Yorker, The Atlantic, The New York Times, National Geographic Adventure, and Outside magazine, among others. His reporting on the investigations into Salazar appeared on the front page, above the fold, of The New York Times in May 2017. In addition to his access to the Gouchers, other sources for the book include former Nike employees, athletes, and coaches; famed sports-scientist and Oregon Project whistleblower Steve Magness; and Olympic marathon gold medalist Frank Shorter, among many others.