Kris Stallenberg 120-min Z2 (Endurance) Pushing #09 This advanced endurance workout uses very short, high-power 'micro-bursts' to stimulate fast-twitch muscle fibers without creating lactate buildup. The foundation of the workout is a steady Z2 effort, in line with Coggan Power Zones, but every five minutes you'll perform a 10-second burst. This enhances neuromuscular pathways and can improve your pedaling economy and overall endurance. Focus on a rapid, sharp acceleration and a quick return to your Z2 pace. bike