Practice running 3.5 miles up a hill, sprinting another 1.5 miles off of it, running over muddy undulating hillocks for 8 miles, along a road for another 1.5 miles, then up an effing great steep, and ever steepening, hill for 2 miles, (be sure to practice getting cramp at this point), then a fast descent over broken boulders for 1 mile, then another 1 mile of track and road running, then 2 miles running on limestone crags and slabs, then a steep 0.5 mile climb to the top of a third hill before the best part of a 6 mile run in to the finish on rocks and mud
