I don't know what tough mudder you're talking about, but most of them are 10-12 miles of running with 20-25 obstacles mixed in. I'm doing one in Minneapolis this may. It should be a lot of fun. I did a men's health urbanathlon in chicago last fall and it was a blast. That one was 9.75 miles with 7 obstacle. One of them was running stairs at soldier field which was badass. Tough mudder's make warrior dashes, muddy buddies, etc look like a walk in the park. I want to say the average finishing time of mudders is like 2 hours, but it's a completion race with no formal timing. Spartan races are another one I'm looking into, similar to the tough mudders but they have a longer variations.