Duncan LarkinDuncan Larkin has covered the sport of running for more than a decade. He's a certified Army Master Fitness Trainer and was a top-300 American marathoner back in 2006. He has won the Himalayan 100-Mile Stage Race and the Mohawk-Hudson Marathon His first book, Run Simple, was published in 2012. Duncan writes about fitness for Outside Magazine, Competitor Magazine, Runner's World, ESPN, and Running Times. Read More Read Less