Kris Stallenberg 30-min Z2 (Endurance) Easy #07 While the power target remains constant in your Z2 (Endurance) zone, this workout uses cadence changes to challenge your neuromuscular system and improve pedaling efficiency. By altering your pedal speed at the same power output, you'll engage different muscle fibers and improve your ability to ride smoothly across various terrains and conditions. This aligns with the Coggan Power Zones goal of building a robust aerobic engine. bike