Check the latest Progress Theory podcast as @freddiereadhead and @thepricep set out their first challenge. In this episode: . • Freddie and Phil lay down the rules for the challenge. • Discuss the determinants of endurance performance. What makes some endurance runners better than others? • Introduce potential training zones based on understanding how the body utilises different energy systems. . Follow their journey as they train for this challenge. Want to improve your 5km and 10km? Get involved and join in.