It's been sitting there for hours. It might not stay down. But every single bite of that soggy pepperoni slice is worth it. You've been eating energy gels and gummy chews for an entire day, and the salty, fatty carbohydrate goodness of pizza just hits the spot like nothing else. However, after this (and maybe a few more pizza outings during your recovery week) you will go back to telling people things like, "Oh, I'm gluten free so no thanks." Or, "I eat clean, so pizza is a no-go."
Until the next finish line, dearest pizza. It will be waiting for you.