Kris Stallenberg 90-min Z2 (Endurance) Medium #08 This workout follows a pyramid structure, building intensity through the lower to upper ranges of your endurance zone before stepping back down. This simulates the effort of a long, rolling hill, demanding sustained power and control. By spending time at various levels within Zone 2, as defined by the Coggan Power Zones, you'll develop a well-rounded aerobic base and improve muscular stamina. bike