"I am not a human. I'm a piece of machinery. I don't need to feel a thing. Just forge on ahead." (Haruki Murakami)
In 1996, Haruki Murakami ran a 100 km marathon around Lake Saroma in Hokkaido, Japan. He devotes a chapter of What I Talk About When I Talk About Running to it and to its consequences, which he calls, somewhat understatedly, "runner's blues". When I read it I thought something like "post-exhaustion stress disorder" might have been more fitting.
As he describes it, the first half of the race gave him no particular difficulties. Although he had run further than he'd ever run before, he remembers it simply as "silently running". But then it begins to get hard. He runs for thirteen miles in constant pain, telling himself that he is not a living being but a machine. (Even this cannot explain his ability to go on, actually. The machine should have been breaking down. Seizing up.) Then he "passes through" into a meditative state, in which he is himself and at the same not himself. "The mind just wasn't that big a deal," at this point.
He had started running in the early morning and it was late afternoon when he finished the race.* He had been running for almost twelve hours. Although he was happy, another emotion took priority. "At this instant relief outweighed happiness. It was like a tight knot was gradually loosening, a knot I'd never even realized, until then, was there."
While he does not diagnose it this way himself, this feeling of a loosening knot, this relief which was stronger than happiness at completing the race, was really a kind of undoing. He had pushed himself too hard and, as a result, was now just relieved. Keep in mind that I think happiness is knowing you will doing something (like writing) the next day. "After this ultramarathon," writes Murakami,
I lost the enthusiasm I'd always felt for the act of running. Fatigue was a factor, but that wasn't the only reason. The desire to run wasn't as clear as before. I don't know why, but it was undeniable something had happened to me. Afterward, the amount of running I did, not to mention the distances I ran, declined noticably. (116-7)
It took ten years to fully get over his "blues". And yet, by the end of the chapter, he writes plainly of himself as "a writer who knows his limits". If so, it seems to me that he has learned it the hard way.
*Update: I had originally written this as though he finished with a time of 4 hours 42 minutes. In fact, he finished at 4:42 pm. His time was 11 hours and 42 minutes.