This morning, before I started my run, I saw something that’s a sure sign of fall. Something that without a doubt means summer is over and my absolute favorite time of the year — for running and otherwise — is finally here. It wasn’t a swath of colorful leaves or a pumpkin on a doorstep. It’s much more subtle, and I almost missed it because I was in such a hurry to get going. As I stood in the morning sunlight, pulling my long-sleeves down over my hands, there it was, right in front of my face…my breath.