In case you hadn’t guessed, I’m a runner. But first and foremost, I’m a mother. Trying to explain why mommy leaves for hours at a time to run or having to justify why I’m too tired to keep up after doing a 50k can be difficult for my children to grasp. The book My Mommy Runs, written by Matt Sorenson and illustrated by Andrew Langston, was a great addition to our library for many reasons.…