Week 1:
Monday 3 mi
Tuesday XT
Wednesday 3 mi
Thursday rest
Friday 3 mi
Saturday 4 mi
Week 2:
Monday 4 mi
Tuesday XT
Wednesday 5 mi
Thursday rest
Friday 4 mi
Saturday 6 mi
Week 3:
Monday 5 mi
Tuesday XT
Wednesday 6 mi
Thursday rest
Friday 5 mi
Saturday 8 mi
Week 4:
Monday 6 mi
Tuesday XT
Wednesday 8 mi
Thursday rest
Friday 6 mi
Saturday 10 mi
Week 5:
Monday 6 mi
Tuesday XT
Wednesday 8 mi
Thursday rest
Friday 6 mi
Saturday 10 mi
Week 6:
Monday 6 mi
Tuesday XT
Wednesday 8 mi
Thursday rest
Friday 6 mi
Saturday 12 mi
Week 7:
Monday 5 mi
Tuesday XT
Wednesday 5 mi
Thursday rest
Friday 5 mi
Saturday 12 mi
Week 8:
Monday 3 mi
Tuesday XT
Wednesday 1 mile walk
Thursday rest
Friday 1 mile walk
Saturday 13.1 mi
Essentially, every Tuesday is a cross training day. These are low impact activities that exercise the heart, build endurance, and strengthen opposing running muscles.
Thursdays and Sundays are rest days.
If you feel radiating pain in your shins, R.I.C.E it and switch to XT only for a week. Shin splints will knock you out of the game, so don't push it. Just train your legs and heart differently. When you do get back in the game, cut back the weekly mileage. Too much too soon, bad shoes, and hard running surfaces can all be a part of this. Take it seriously, when I didn't, I was out of running for 8 weeks....and I couldn't jump, walk down stairs, or get out of bed without feeling like me legs were broken (because they pretty much were). Painful.
This plan is for an athletic person who likes a challenge. Originally I got a beginner plan and over the years it has gotten more and more challenging. If you can run two miles without stopping and want to make sure you will cross that line confidently, this is your plan. Alternatively, one could cap the Saturday runs at 10 mi and be just fine. I like them at 12 so I can be SURE I can run 13 :)
Be safe, run at a steady pace, and get sweaty people!