4 Exercises for Tough Mudder / 5 for Spartan

I had a discussion with a guy about Tough Mudder and training for it and to boil everything down, there are 4 exercises that you need to do as much as possible to train:

1 - Run

2 - Pull Ups

3 - Sit Ups

4 - Push Ups

If you are training for a Spartan, insert Burpees into the #2 position.

I am the first person to over analyze and complicate a workout routine. I have developed it over time, research and experience. Anyone reading this will have great suggestions as to how to improve the four exercises listed above. 

But to keep things simple: You need leg strength and endurance, upper body strength and core strength. Those four exercises can be done by anyone, anywhere. Do them as much as you possible can.