Kris Stallenberg 75-min Z2 (Endurance) Medium #06 A workout of patience and control. This session features a single, long, and gradual build across the entire endurance zone. Starting at the bottom of Zone 2 and finishing at the top, this workout challenges your focus and aerobic system. It's a great simulation for negative-splitting a long effort, all within the foundational endurance range of the Coggan Power Zones. bike