Preposições usadas com o Verbo Run

Hey, guys.
I need some help with the correct (or the best, if there's more than one acceptable answer) preposition to use the verb RUN in the contexts below.

1) Places - do I use "in" or "at"? I've seen both. I guess "in" would be used in a more specific context, right?
"I'm going to run at the park."
"I'm going to run at Central Park."
"I'm going to run at the club."
"I'm going to run in Central Park."


2) Marathons and races. I've seen examples without prepositions or articles.
"She's going to run the NYC Marathon."
"She's going to run São Silvestre."

Thanks a lot.