When I sat down at the computer today, my intention was not to provide an in-depth analysis of running tethers and how I use them, but my mind goes where it goes.

I became increasingly lost in thought. I imagined the elation of capturing a new PR at the Greater St. Louis Marathon. I recalled the relentless hills of Bowling Green, Kentucky, scene of my worst marathon finish to date. I remembered the physical and mental challenge of running six loops around Forest Park in preparation for my first 50-miler.

Once doubt infiltrates my consciousness, it doesn’t just kick back and put its feet up. It goes to work, generating thoughts of negativity that feed off each other and multiply, until I am convinced that the task at hand is impossible and it’s okay to quit.