Zach Bitter

Zach Bitter is an American ultramarathoner and endurance athlete who holds multiple world records, including the 100-mile world record with a time of 11:19:13 set in 2019. He is known for his expertise in low-carb, high-fat nutrition strategies for endurance performance and frequently shares insights about ultrarunning training and fueling on podcasts and social media. Bitter has become a prominent voice in the endurance sports community, advocating for metabolic flexibility and challenging conventional nutrition wisdom in distance running.