Weblog Alex Reuneker

Last Friday, my wife and I took our son to Leiden to run the Singelloop – a very family friendly running event. It was fun, although I was used to starting and running in front. Pushing a stroller, I though I shouldn't start in front this year, because that should be reserved for people actually racing. It took around 2 kilometers to get used to running really slow and just enjoying the run as a family activity instead of a running activity.

Stroller-running at the Singelloop 2025

The biggest challenge was to maneuver the stroller around and past other runners, but I kept in mind that I was the 'exception' here and I should watch out, not others. What definitely helped, were all the positive reactions and cheers by other participants and the massive amount of supporters along the route. Thanks, Leiden!

I keep finding myself fiddling with treadmill speeds and the calibration thereof. I am fully aware though, that really exact speeds don't matter that much in running/training, but I just find it fascinating. I also kept finding myself calculating intermittent speeds between two calibrated speeds in a very inefficient way. Now I've come to value inefficiency a bit more in the last couple of years (or, better said, I've come to devalue efficiency...), but this task was just to repetitious and, to be frank, boring. That's why I've added an interpolation function to the treadmill calculator.

Interpolation for calibrated treadmill speeds

With this new function, you can enter two previously calibrated speeds and calculate the 'correct' speeds in between. For instance, when you calculated the true speed of your treadmill at 10 and 16 kph, you can calculate the speeds at 11, 12, 13, 14 and 15 kph. Keep in mind that linear interpolation is used for this, which assumes the deviation of your treadmill is constant. This probably is not an entirely correct assumption, but that's the margins of the margins, I'd say. Anyway, if you find it useful, let me know!

Link: https://www.reuneker.nl/treadmill

Last Friday, 11 April 2025, around 20 linguists from LUCL – the 'LUCL Runners' – ran the Leiden Singelloop. All running linguists completed the +/- 6.5km course along the ‘singels van Leiden’. Afterwards, we enjoyed each other's company during the annual post-run party at Olga van Marion and Ton van der Wouden’s house along the route. Thanks to LUCL for sponsoring and all colleagues who supported us during the run!

The LUCL team of 2025

It was a bit of a challenge to run with our son in his stroller along parts the small, crowded route, but it was fun!