Originally Posted by
RichardInSF
Run Pit, eh? Great name. Maybe the competition was called "Runner's
Armpit."

(Above link added by me

)
Many Japanese associate the word "pit" only with the pits for car races. This may be the reason why they named it so.
I am looking up "pit" in an dictionary, oh, I understand what you mean.
They should have had the naming checked by native speakers.