I attempted to start a thread here asking for some advice about training for Tough Mudder
The more videos I see of participants from Tough Mudder the less I'm worrying about it too much. See the video here
where there is a line for the obstacle.
I'm going to get a pair of Vibram Trek Sports to run in. I've been running in Vibrams for almost 2 years now, but I need to build some distance in them. A couple of miles are ok, I'm concerned hitting close to 12 miles in one day would leave me debilitated. I've been following a strength and conditioning program recently that focuses on the big lifts plus some assistance and then some prowler work. After that I hit some runs in my Vibrams to get some distance and mix in some sprinting in the middle of the run, basically a fartlek run.
There is a track nearby and I've thought about hitting that up for some 300m and 400m repeats to build up some endurance, but I'm not sure that will do more than what the prowler does for me.
Edit: Reason for the Vibrams is I've rolled my ankle several times on rough terrain in running shoes with a thick sole. The thin to no-sole of the Vibrams really helps me with ankle stability. Basically you reduce the length of the lever arm so when my ankle rolls with the rough terrain there is not as much force on the ankle joint as with a thick soled running shoe. Go from a severely rolled ankle to a slight roll that does not leave you injured and in agony. Also, the easy cleaning of the Vibrams makes them an ideal choice for after the race. I think several people just throw their shoes away after the race or are planning on doing that.