Kris Stallenberg 30-min Z2 (Endurance) Pushing #02 This session challenges your ability to recover while still working. By alternating between the top of your Z2 (Endurance) zone and just into Z3 (Tempo), you'll improve aerobic conditioning and learn to clear lactate efficiently. This mimics the variable demands of group rides or undulating terrain, a concept well-defined within the Coggan Power Zones framework. bike