Kris Stallenberg 45-min Z2 (Endurance) Pushing #08 This session uses two long, gradual Z2 Ramps to sweep through the entire endurance zone. By slowly increasing the demand, you'll challenge your body to remain efficient as fatigue builds. This workout is an excellent way to explore the full range of your Z2, as defined by the Coggan Power Zones, and improve your feel for different effort levels. bike