Kris Stallenberg 60-min Z2 (Endurance) Medium #08 This pyramid workout varies interval duration to keep the session mentally stimulating while accumulating valuable time in Zone 2. You'll build up to a peak 12-minute interval and then work your way back down. This structure helps in learning to pace longer efforts. The entire working portion of this ride adheres to the aerobic endurance principles of the Coggan Power Zones, building your base for future, harder efforts. bike