When you're running long distances, self check-ins help you keep it together. I usually start from my feet and move up. In addition to passing the time, monitoring the parts of your body that are liable to fall apart makes you better equipped to self-medicate and make good decisions at upcoming aid stations.
But on a metaphysical level, these check-ins deepen the connection between body and mind. Of the many aspects of trail running I enjoy, it is the deep bond within the body that brings me closer to myself.
One of my check-in mantras is "How good does my water taste?" The better my water tastes, the more dehydrated I probably am. I'll check to see how much water I have left, when the next aid station is, and adjust my rationing strategy accordingly.
Sweeping the trails at Armstrong Redwoods, I was on my own in the sweltering heat. Arriving back at the bottom of the hill, aid station cleaned and gone, concerned the next one would be too, water rationing took on a new meaning. Ascending that hill, again, my water tasted really, really good.