Has anyone here ever done one of these?

[Glassunion]

I'm signed up for the Tri-State in November.

http://toughmudder.com/

I'm in average shape. To toughen up and get in shape I'm doing the following:
Running about 10K a week and adding 2K every week. I.E. I'll be running 12K next week.
Cardio, cardio, cardio... P90X
Added rusty nails to my breakfast.
Hitting a heavy bag filled with thumb tacks and kittens.
Drive to Chuck Norris' house for a punch in the face from his beard-fist every morning.
Having my wife taze me when I step out of the shower.

Has anyone ever done one of these? If so... How hard was it?