Ryan Hall left the pro running circuit in 2016. The U.S. half marathon record-holder and unofficial American marathon record-holder has a new passion these days — bodybuilding. From running a sub-2:05 Boston Marathon in 2011 to putting on 40 pounds of muscle, Hall found a new fulfilling way of expressing himself after his body told him his competitive long-distance running days were over.

The two-time Olympian joins Dirk to discuss the process of shifting disciplines, the challenges and benefits of coaching his wife Sara, and the coaching lessons he's learned throughout his 20-year career and beyond.