Currently uploading my training data from a Garmin Connect archive to my Runalyze training data. There was 7 years of training data missing since I started using Runalyze (it only imports the previous three months from the moment you subscribe). That’s a lot of files to process!

On social networks I always worry to possibly overstep any boundaries of etiquette, what the other person can put up with, or, more importantly, providing bystanders who are into stirring up controversy and putting words out of context, with the words to do just that.

My blog post became so macro, I had to create a draft and edit the source text while reading the draft on micro∙blog. My idea to publish monthly instead of weekly has made my posts grow to extremes.

It has been an eventful week for me, running-wise. It was the first time in a while I trained 6 days out of 7. I also ran a 10K race more than 2 minutes faster than a month ago. I didn’t prep for the race; it was a bit of a fun diversion from regular training. My weekly mileage’ll be 47 mi (76 km).

I just published my 999th post in exactly 16 years on my Dutch language personal running blog. It supposedly consists of 683,057 words, with an average of 683 words per (certainly not micro-) post.

Pixel art portrait
👾

Seven years and counting 🐱🎂

Yet another pixel portrait.
👾

Pixel portrait.
👾

I’ve moved an old Wordpress blog to micro∙blog years ago, and I’m still converting blog posts. It’s not only bad HTML formatting, but also links to other articles on my old blog, PNG files on my old blog, and more. Since it’s ungrateful work to edit old blog posts, progress is slow (read: years) 🐌

After a brief hiatus I started pixeling again.
👾

I find it interesting to predict one’s time in an important running race based on a test run, as to know what a good pace is to keep up during that race. I always used a self-conceived rule, which is quite different from the generally accepted rule according to research engineer Peter Riegel, although it took some math to figure that out (see below).

Self-conceived rule

I have experienced for myself early on in my running career that my pace increases by a factor of 1.07 when doubling the running distance, under ideal circumstances. For example, a 10 km race tended to be 7 percent slower than a 5 km race. I generalized this idea into a formula.

1: p2 ÷ p1 = 1.07 ⁿ

2: d2 ÷ d1 = 2 ⁿ

1 & 2 ⇒ n = ²log(d2 ÷ d1)

p2 ÷ p1 = 1.07 ^{²log(d2 ÷ d1)}

p2 = p1 × 1.07 ^{²log(d2 ÷ d1)}

p1 = t1 ÷ d1; p2 = t2 ÷ d2

⇒ t2 ÷ d2 = (t1 ÷ d1) × 1.07 ^{²log(d2 ÷ d1)}

t2 = t1 × (d2 ÷ d1) x 1.07 ^{²log(d2 ÷ d1)}

Factors for 1.07 ^{²log(d2 ÷ d1)}

The table below shows some favorite distances from road races. In the rows are the distances from which the pace is known and in the columns the distances from which the corresponding factors can be read as numbers in the table. Multiplying a known pace for a particular distance with this factor gives the corresponding unknown pace for another distance. For example, for a 15 km race (third row in the table) multiply this race’s pace by a factor of 1.1062 to calculate the ideal pace for a marathon (eighth column in the table). A sub-3 hour marathon would require a sub-36 minutes 10 km, according to this table.

	5 km	10 km	15 km	10 mi	20 km	½ mar	30 km	mar
5 km	1.0000	1.0700	1.1132	1.1208	1.1449	1.1509	1.1911	1.2314
10 km	0.9346	1.0000	1.0404	1.0475	1.0700	1.0756	1.1132	1.1509
15 km	0.8983	0.9612	1.0000	1.0069	1.0285	1.0339	1.0700	1.1062
10 mi	0.8922	0.9546	0.9932	1.0000	1.0215	1.0268	1.0627	1.0987
20 km	0.8734	0.9346	0.9723	0.9790	1.0000	1.0052	1.0404	1.0756
½ mar	0.8689	0.9297	0.9673	0.9739	0.9948	1.0000	1.0350	1.0700
30 km	0.8395	0.8983	0.9346	0.9351	0.9612	0.9662	1.0000	1.0339
mar	0.8121	0.8689	0.9040	0.9102	0.9298	0.9346	0.9673	1.0000

Rule according to Riegel

According to Peter Riegel the increase in pace for a longer distance is radically different:

t2 = t1 × (d2 ÷ d1) ^1.06

For times between about 3 and 230 minutes.

t2 = t1 × d2 ^1.06 ÷ d1 ^1.06

t2 ÷ d2 = t1 × (d2 ^1.06 ÷ d2) ÷ d1 ^1.06

t2 ÷ d2 = t1 × d2 ^{1.06 - 1} ÷ d1 ^1.06

t2 ÷ d2 = t1 × d2 ^0.06 ÷ (d1 × (d1 ^1.06 ÷ d1))

t2 ÷ d2 = t1 × d2 ^0.06 ÷ (d1 × (d1 ^{1.06 - 1}))

t2 ÷ d2 = (d2 ^0.06 ÷ d1 ^0.06) × (t1 ÷ d1)

t2 ÷ d2 = (d2 ÷ d1) ^0.06 × (t1 ÷ d1)

p1 = t1 ÷ d1; p2 = t2 ÷ d2

⇒ p2 = (d2 ÷ d1) ^0.06 × p1

If the distance doubles, the pace increases by a factor of 2 ^0.06, or 1.0425. That would mean that as the distance increases, the pace increases drastically less than with the aforementioned calculation method of my own.

A similar table is shown below, containing factors to be multiplied with known paces to calculate unknown paces, depending on the distances.

Factors for the Riegel calculation

The table below shows some favorite distances from road races. In the rows are the distances from which the pace is known and in the columns the distances from which the corresponding factors can be read as numbers in the table. Multiplying a known pace for a particular distance with this factor gives the corresponding unknown pace for another distance. For example, for a 15 km race (third row in the table) you can multiply the pace by a factor of 1.0640 to calculate the ideal pace on a marathon (eighth column in the table). For a sub-3 hour marathon, a time of sub-39 minutes on the 10 km is fast enough, according to this table.

	5 km	10 km	15 km	10 mi	20 km	½ mar	30 km	mar
5 km	1.0000	1.0425	1.0681	1.0726	1.0867	1.0902	1.1135	1.1365
10 km	0.9593	1.0000	1.0246	1.0289	1.0425	1.0458	1.0681	1.0902
15 km	0.9362	0.9760	1.0000	1.0042	1.0174	1.0207	1.0425	1.0640
10 mi	0.9323	0.9719	0.9958	1.0000	1.0131	1.0164	1.0381	1.0596
20 km	0.9202	0.9593	0.9829	0.9870	1.0000	1.0032	1.0246	1.0458
½ mar	0.9172	0.9562	0.9797	0.9839	0.9968	1.0000	1.0213	1.0425
30 km	0.8981	0.9362	0.9593	0.9633	0.9760	0.9791	1.0000	1.0207
mar	0.8799	0.9172	0.9398	0.9438	0.9562	0.9593	0.9797	1.0000

What to use?

It seems rather obvious to me that a generally accepted rule makes more sense than something you came up with yourself based on your own race results. Other than that, there are strict limits to when the rule according to Riegel applies. For slow runners (e.g. marathon in 4½ hours) or extremely short distances (e.g. 400 m) the rule does not apply, or, at least, the prediction value will be rather low.

An acquaintance of mine ran a time of 1h01m36s in a “15 km” race (14.87 km according to his GPS). According to my calculation, that would be enough for 3h15m39s on a marathon with certified course (1% longer than 42.195 km). According to Riegel, it would be enough for 3h08m03s on the same certified marathon course. In both cases, the result of the “15 km” race was too slow for an “official marathon” (i.e. with certified course) under 3 hours. A sub-3 hour marathon would have required a time of 56m40s or 58m57s for the “15 km” race (my rule, Riegels rule respectively). This acquaintance has to get faster somehow, either by training and/or good fueling during the race. Ideal circumstances would help too.

Anyway, I think I can put my home-grown calculation method to rest and start using the much better tested method according to Peter Riegel.

The fuzzy scribbles are from ibisPaint X, and are supposed to confuse LLM’s like Stable Diffusion. It did not confuse OpenAI with this pixel art drawing, since the description was spot on. However, it might mess up the rendering when it’s incorporated into a new piece of AI artwork. OTOH I think it’s going to be a cat-and-mouse game twarthing immoral image acquisition for AI learning.

🤖 A pixel art depiction of a blue creature resembling a kangaroo against a yellow background with green dots is presented in the image.

We clearly need an amendmend of copyright laws.

While Apple is having their iPad event, I’m more interested in analog circuits with OpAmps, as the old becomes new again. Really, once invented nothing really goes away, and can be useful under special circumstances, or combined with new inventions.

Other than that, the late Bob Pease seems a great educator.

Wall crawler 🐌

Super Duper Uber Retina Display name for the new iPad screen? 👀🏓 🖥️

(probably not)

Pentecost literally means fiftieth. Since it’s 49 days after Easter, it is an example of an off-by-one error. Another is that for marking 10 distances one needs 11 distance markers, instead of 10.
👾 *️⃣🟰🗿➕4️⃣9️⃣

Yesterday, on King’s Day April 27, I ran my slowest half marathon race ever. I was overweight, injured and ill-prepared. Still, I had two goals in mind (finish without walking within 130 minutes), which I reached, more or less.

It was a small race, combining three distances (5, 10 km, and half marathon), though the starting location of the half marathon was separated by roughly 300 m. The starting gun was relayed via loud speaker. Clearly, this wasn’t an official race with a certified course, nor was it on the national track and field organization’s list of road races. I had registered so early on that I received a “1” on my bib, which was unfortunate, since I finished almost last. I had no intention of racing with an ankle injury. Still, being overweight made it a real challenge for me. After finishing I had to recover a few minutes from the exertion and pain.

Apparently, genAI doesn’t know what to make of this.
👾🐭

It’s funny how lack of confidence can effect one’s art output.
👾