Kris Stallenberg 30-min Z2 (Endurance) Pushing #08 Build your endurance base with a twist. This workout combines solid Z2 (Endurance) blocks with short, controlled surges into the Tempo zone. This improves your ability to handle changes of pace without burning out. It's a dynamic application of the Coggan Power Zones, focusing on aerobic fitness while teaching the body to quickly recover from harder efforts. bike