Zone 4 / Threshold

Zone 4 running is where performance begins to sharpen. Known as the threshold zone, it’s the intensity level where your body learns to manage fatigue, clear lactate efficiently, and hold a faster pace for longer. Training here builds both speed and endurance — making it essential for runners aiming to break through plateaus. Zone 4 is tough, but with the right structure and recovery, it becomes a powerful tool in your training arsenal.