This 100 mile Ultramarathon Trail Running Plan assumes an athlete that has intermediate experience with running ultramarathons. Examples could be finishes in the 50k or 50 mile distance. Athletes using this plan are likely to be targeting a finish at the 100 mile distance vs. a competitive performance. This plan assumes a 100 mile race with approximately 14,000ft – 22,000ft of gain, such as, but not limited to, Leadville, Western States, Superior, Angeles Crest, or Massanutten. This plan will start with weekly milage of 35 miles per week across five days of training per week, with a 10 mile first long run. The plan will top out with a 75 mile week and six days per week of training, two focused workouts per week, and a 25 mile long run. This plan integrates three night runs and includes an alternate set of weeks to allow for a practice/tuneup race in the latter half of the plan. Each fourth week is a scheduled recovery week with a reduced workload. This plan assumes access to trails that offer rolling or hilly terrain.