Kris Stallenberg 90-min Z2 (Endurance) Easy #02 This session breaks down the endurance work into manageable intervals. By structuring the ride this way, we can maintain focus on quality and form. According to the Coggan Power Zones, maintaining Z2 (Endurance) power promotes aerobic adaptations. The short recovery periods allow for a mental reset without dropping the physiological stimulus. Concentrate on hitting the power target consistently for each interval. bike