Running versus Going Running

I should have realized there was a difference, but now I have been set straight for good.

Track season is over, and Edward is taking a 2 week break before he can run again. After school yesterday, he stopped home to pick something up and said he was going to play ultimate frisbee with his friends. Oh, I said, you are playing that without running? Can you walk and throw frisbees? He said that he is allowed to run, he just can't "go run." Then like the math professor he is destined to become, he went on to explain that it's like the relationship between a square and a rectangle. All squares are rectangles, but not all rectangles are squares. Oh, I said. So not all running is "going running" then. Yes, he said, we are just not allowed to do constant strenuous physical exercise.

Well, that explains it.