In Season 3, Episode 23 Dr. Bubbs interviews Zach Bitter, American and world record holder in the ultra-marathon. In this episode, Zach shares how he first got into racing, how to build up from marathons to ultra-marathons and how far out you should start training for an ultra. Zach also discusses the importance of building an aerobic base for ultra-marathons, his recent win in the San Diego 100-mile race, and common mistakes made by recreational ultra athletes. Finally, Zach shares his fueling strategy during training and competition, common nutrition pitfalls he sees with clients and what’s next for him on the performance front.