When a person need study a lot, we say "tienes que hincar los codos"
go out running: salir corriendo.
for example. You are in a shop, and you see come an old boyfriend that you do not want to see, you go out of shop quickly.
we say:
"salí corriendo" (evidently you do not running., you just go out quickly)
también decimos
"salí por pies"