Kris Stallenberg 30-min Z2 (Endurance) Easy #05 This workout primarily targets your Z2 (Endurance) zone but includes very short 'bursts' into low Tempo (Z3) to keep your system engaged. These brief efforts, based on the Coggan Power Zones model, are just enough to stimulate the system without accumulating significant fatigue, allowing the focus to remain on aerobic development. The goal is to quickly settle back into your endurance pace after each burst. bike