John Davis is a coach, writer, and scientist with a passion for marathon training. His new book, "Marathon Excellence for Everyone," combines practical wisdom and the most up-to-date scientific findings, creating a modern marathon training system. The book's plans are thoughtful, scalable, and digestible. It's a must add to your running library. John holds a PhD in Human Performance from Indiana University, and he regularly contributes to our body of evidence-based marathon understanding on his website: runningwritings.com marathonexcellence.com runningwritings.com columbusrunning.com