Kris Stallenberg 120-min Z2 (Endurance) Easy #05 Explore the full range of your endurance zone with this workout. You will alternate between the lower and upper ends of zone Z2 (Endurance), based on the Coggan Power Zones framework. This session improves your ability to handle subtle changes in pace and terrain on long rides, building a robust aerobic base. The goal is to make the transitions smooth and controlled, maintaining efficiency at both intensities. bike