Kris Stallenberg 75-min Z2 (Endurance) Medium #09 Challenge your endurance with a set of descending intervals that climb in intensity. As the intervals get shorter, the power target nudges toward the top of your Zone 2. This structure, guided by the Coggan Power Zones, teaches pacing and helps you stay strong as fatigue begins to set in. It's an excellent workout for building mental toughness alongside your aerobic capacity. bike