Two-and-a-half years ago, in the middle of covering the Obama-Clinton race for the Democratic nomination, I found myself in front of a mirror, and not too pleased with what I saw.

Eating and drinking too much, sleeping too little, away from home for too long, I needed to make a bit of a course correction. Long a believer in the idea that "desperate times call for desperate measures," I decided to check off a box that had been hanging around on my life's to-do list a little too long - run a marathon.

The process of training for the marathon turned out to be nothing less than a chase after that most elusive of emotional commodities - happiness. Last November 1st, I ran and completed the New York City Marathon, and I shall be attempting to do it again this year. Here's a column that was first published in the New York Times about a curious phenomenon I noticed on the day after I finished the race last year.