Featuring the proven 80/20 intensity balance described in Matt Fitzgerald's bestselling book 80/20 Running, this Ultra Marathon 50 Mile/100 Kilometer Level 0training plan will provide you with the same workout structure used by the most successful runners in the world. TARGET ATHLETE This level is intended for athletes without a running background attempting their first ultra event. You should be able to comfortably run for at least 90 minutes before you start the plan. 100% STRUCTURED ...