How I Ran a 2:40 Marathon | Chicago Marathon 2025

Thank you to Runna for providing my training program! Try Runna for FREE for two weeks: https://web.runna.com/redeem?code=JMILLER In this video, I attempt to run a 2:39 marathon as I take on the 2025 Chicago Marathon! Welcome to the 2:39 marathon prep series! On October 12, 2025 I'll be running my 15th marathon at the Chicago Marathon and aiming to run a new personal best of 2 hours and 39 minutes. In this series, I'...