These 12 Workouts Build Ultramarathon Fitness (#3)

Ultrarunning performance plateaus when athletes rely solely on easy, zone 2 training, necessitating the development of multiple physiological systems through structured interval work. Effective training focuses on three core categories: VO2 max intervals to improve cardiac output and oxygen delivery, tempo intervals to enhance lactate threshold and mitochondrial density, and steady-state running to build high-end aerobic durability. By utilizing twelve repeatable workout structures—ranging from short, high-intensity uphill repeats to sustained 60-minute aerobic efforts—runners can drive specific physiological adaptations without unnecessary complexity. Key to this approach is maintaining strict intensity discipline, ensuring recovery periods remain easy enough to allow for maximum effort during work intervals. Mastering these foundational structures creates a powerful endurance engine capable of maintaining strong pacing during the late stages of an ultramarathon.