Kris Stallenberg 30-min Z2 (Endurance) Easy #09 This session keeps you on your toes with frequent but small changes in power, all within the Z2 (Endurance) range. These one-minute fluctuations, guided by the principles of the Coggan Power Zones, mimic the subtle variations of riding outdoors. This helps improve your focus and ability to control power output, making your aerobic base more resilient and adaptable. bike