On Sunday, 20 September, I ran the Kassel Half Marathon. It was my third time at this race, after 2024 and 14 September 2025. In 2025 I also ran a test half marathon organised by Kassel Marathon, so this was my fourth half marathon.
Last year was sunny, and I finished in about 2 hours 37 minutes. This year it rained, and my watch stopped at about 2 hours 51.
So this year was slower by roughly a quarter of an hour. My instinct as a physicist is to explain that number, and I can't, at least not honestly. Two runs a year apart, on different days, in different weather, after a different year of training and of life: every variable changed at once, and one pair of measurements cannot separate them. In the lab I would not draw a conclusion from data like that, and I won't draw one here.
What the times leave out: both of the last two years began with weeks of training, and both ended in the same stadium with a medal.
I run along the Fulda and the trails around Kassel through the year. Long runs take the same sustained effort and discipline that experimental research does.
The last two Septembers at this race: one sunny, one wet.