Kris Stallenberg 90-min Z2 (Endurance) Easy #10 This session uses a variety of block durations and intensities all within the Z2 (Endurance) range to keep the body and mind engaged. This approach, grounded in the Coggan Power Zones framework, helps you adapt to the subtle changes in effort required on a typical outdoor ride. By mixing up the stimulus, we can improve aerobic conditioning while preventing monotony. Focus on hitting the target for each distinct block. bike