Mud Run

I've signed up for the Camp Pendleton Mud Run in June. The website describes it as a "challenging 10K run with hills, tire obstacles, river crossings, two 5-foot walls with mud on both sides..." etc, etc. My friend and coworker encouraged me to sign up with her and I figured, why not? I really haven't started training for this thing yet, other than my typical 3 day a week workout. I need to step it up a notch, and fast, otherwise I will be hurting come competition time. Now that I've put it out there, I will feel more compelled to train for it!