This is my exact training plan for my first 50k!

If you are thinking about running your first Ultra trail run this is for you! This is a progressive training plan to increase your mileage over the course of 10-weeks. 

You will get a variety of workouts to prepare you for this very physically and mentally demanding event. With this training plan, you will not need to run more that 18 miles in one workout session.  The program is built from the perspective of TOTAL weekly milage. It is very important you are doing the workouts in the specific sequence given. Cross-training, short incline intervals, long runs, agility work, upper body muscle endurance, and long brisk hikes/trail runs are the basic structure of this program.

You get 4 workouts a week to:
+increase VO2 MAX
+increase power, agility, stability
+increase muscular endurance
+increase cardiovascular endurance 

FYI: week one of this program starts with a 7mile run... if you are going to be running an ultra-running event in 10- weeks you should be ready to start around this level.