What Is "Zone 2 Training"?: Experts' Viewpoint on Definition, Training Methods, and Expected Adaptations.

Summary: Everyone in the fitness world seems to be talking about "Zone 2 training" to boost endurance, but definitions often vary. To clear up the confusion, a panel of 14 sport scientists and coaches gathered to create a unified definition. They concluded that Zone 2 training is exercise performed just below the "first lactate threshold"—essentially, an intensity where you can still hold a conversation, just before your muscles start to burn significantly. While this low-intensity, high-volume approach triggers important heart and muscle adaptations that build stamina, the experts noted these benefits aren't exclusive to Zone 2 and can overlap with slightly harder workouts.