Brief - Memoir of Murakami who is a Novelist by profession as well as a long-distance marathon runner.
Summary of the book:
Maybe it's pointless act like pouring water in the pan which has a hole in the bottom, but at least the effort you into it remains. Whether it's good for anything or not, cool or totally uncool, in the final analysis, what's most important is what you can't see but can feel in your heart. To be able to grasp something of value, sometimes you have to perform seemingly inefficient acts.
My time, the rank I attain, My outward appearance - all of these are secondary. For a runner like me, what's really important is reaching the goal I set myself, under my own power. I give it everything I have, endure what needs enduring, and am able, in my own way, to be satisfied.