Kris Stallenberg 45-min Z2 (Endurance) Medium #06 This session builds your muscular endurance and mental toughness by progressively extending the time spent in Zone 2. Each block gets longer, challenging you to maintain focus and form. This method is a great way to apply the Coggan Power Zones framework to build true long-ride stamina. The short rests are just enough to regroup before the next, longer effort. Finish strong! bike