The act of taking a marathon finishers shirt that is too big for you for no good reason (ie. I can "sleep in it" or my kids would like this shirt), leaving only smaller shirts for the later, chubby runners.
WRM race worker: what size shirt do you want?
skinny/fast runner: Give me an XL, I can sleep in it.
chubby/slower runner: Can I get a finisher shirt?
WRM race worker: All we have left are Small and Mediums
chubby/slower runner: Those twigs shirt blocked me!