Sold out, in November!

On 11 November 2026, I looked at next spring’s races on EuroSlam, my race calendar. Lisbon Half: sold out. Prague Half: sold out. Vienna, Hamburg, Rotterdam and Barcelona: sold out too. And spring is still four months away.

To be honest, for me that’s not all bad news. I ran Lisbon and Prague in 2024, and both got hot. In Lisbon, the sun came out after 10:30, and my Garmin showed an average of 28°C (82°F). I finished in 1:46:46. In Prague, I poured a glass of water over my head at every hydration point, let the 1:45 pacers go after 7 km and finished in 1:50:25.

My two fastest half marathons were both at 15°C or cooler: 1:41:09 in Bucharest in 2025, and 1:42:05 in Valencia in 2024, in steady rain.

Long story short: if your spring PB plan was Lisbon or Prague, a cooler race might be the better plan anyway. So I sorted everything that’s still open by how warm race day usually gets.

What’s already gone

On 11 November 2026, EuroSlam showed 18 spring races in nine countries as sold out:

• 7 Mar: Lisbon Half
• 14 Mar: Barcelona Marathon · CPC Loop Den Haag (half)
• 21 Mar: Venloop (half) · Frankfurt Half
• 3 Apr: Prague Half
• 11 Apr: Rotterdam Marathon · Zürich Marathon and Half · Linz Half
• 18 Apr: Vienna City Marathon and Half · Manchester Marathon
• 25 Apr: Hamburg Marathon and Half
• 2 May: Belfast City Marathon
• 22 May: Göteborgsvarvet (half)
• 29 May: Stockholm Marathon

Göteborgsvarvet I can live with. I ran it in 2023 at 21°C, which felt like 32°C (90°F) in the sun, and finished in 1:48:38. My report started with “Sorry, Göteborg, I won’t be coming back.” I meant it. 😊

For 2027, I’m going to Zagreb: the ZAGREB21 Spring Half Marathon, on 21 March. It’s a smaller race, fast but without all the show of the big ones. But I want to keep filling my EuroSlam passport, and Zagreb gets me the Croatian stamp.

How I sorted the rest

Every race page on EuroSlam shows a typical race-day high: the usual daytime high on that date in past years. It isn’t the temperature at the start. Most races start in the cool of the morning, but the high tells you how warm the second half can get.

It doesn’t tell you about the sun, and as you can see above, the sun is what got me in Lisbon and Prague. So treat it as a first filter, not a forecast.

On 11 November 2026, 50 spring races in 23 countries were open for entry, all but two with dates confirmed by the organisers. Thirteen of them usually stay at 15°C (59°F) or cooler.

Still open, and usually cool (15°C or less)

• adidas Premiärhalvan, Stockholm (half), Sat 24 Apr: typically 9°C · about €63
• Helsinki City Half, Sat 8 May: typically 10°C · €65
• Bergen City Marathon (half and full), Sat 24 Apr: typically 10°C · €76 half, €85 full
• PKO Gdynia Half, Sat 24 Apr: typically 11°C · about €40
• Energa Gdańsk Marathon, Sun 25 Apr: typically 12°C · about €52
• Kaunas Marathon (half and full), Sun 25 Apr: typically 13°C · fee on the organiser’s site
• Swansea Half, Sun 21 Mar: typically 13°C · fee on the organiser’s site
• Düsseldorf Marathon (half and full), Sun 18 Apr: typically 14°C · €100 half, €120 full
• Cluj-Napoca Marathon (half and full), Sun 11 Apr: typically 15°C · €42 half, €47 full

I ran Helsinki in May 2024 and finished in 1:47:13. The wind kept me cool from start to finish, but I found the course too hilly for a PB.

I’ve never run Cluj-Napoca, but it’s on my to-do list for Romania.

A little warmer (15 to 18°C)

• Riga Half, Sun 16 May: typically 16°C · €40. The only open spring race that EuroSlam rates Fast.
• Luxembourg Night Half, Sat 8 May: typically 16°C, but it’s a night race, so the daytime high matters less · €50
• Enschede Marathon (half and full), Sun 11 Apr: typically 17°C · €45 half, €75 full

I ran the 5K at the Enschede Marathon in April 2026: 25:11, at 11°C and overcast, three weeks after an adductor strain. In my report, I said I’d come back one day for the 10K or the half.

Also open in this band: Geneva (9 May, half and full; the half’s date isn’t confirmed yet), Milton Keynes (3 May, half and full), the Gozo Half (25 Apr), Bratislava (11 Apr, half and full), Leiden (9 May, half and full), the Linz Marathon (11 Apr; the half is sold out) and the Edinburgh Half (30 May).

The warm end (18°C and up)

If heat slows you down the way it slows me, I’d book these as trips, not PB attempts.

• 18 to 20°C: Radenci (15 May), the Chișinău Half (25 Apr), Thessaloniki (4 Apr, date not confirmed yet), the Madrid Half (4 Apr), the Crete Marathon in Chania (11 Apr), the Vilnius Half (22 May), the Milano Marathon (4 Apr), Padova (18 Apr), the Dubrovnik Half (25 Apr) and the Belgrade Marathon (18 Apr)
• Above 20°C: the Belgrade Half (17 Apr), Salzburg (23 May), Würzburg (23 May), the České Budějovice Half (29 May), the Athens Half (25 Apr), the Jesolo Moonlight Half (22 May), the Axios Half in Greece (16 May) and the Prague Marathon (2 May)

My quick picks

• Coolest race day: Stockholm’s Premiärhalvan (typically 9°C)
• Best value among the cool ones: Gdynia (about €40)
• Fastest rating: Riga
• My pick: Riga. It’s fast, it counts toward the Baltic Slam in my EuroSlam passport, and I really like Tallinn, which isn’t far away. To be honest, I think all three Baltic countries are lovely places to visit.

Before you enter

• Check the organiser’s page. Everything above is what EuroSlam showed on 11 November 2026. Each race page links to the organiser’s registration page.
• Fees often go up in steps, so the fee above may already be out of date.
• 51 more spring races don’t show an entry status yet. April has its own page, and March and May are linked from it.

Where the list comes from

EuroSlam is my personal project: I turned my race-planning Google Sheet into a website. It’s a free calendar of marathons and half marathons across Europe, with dates from the organisers, past race-day weather and hotels near the start. Some hotel links on the site earn me a small commission, at no extra cost to you.

I’ll do the same list for autumn 2027 once its entries open. Follow me here if you’d like to see it. And if you’d rather have it in your inbox: once a month, EuroSlam sends one short email with the European races that open entry, the ballots coming up and the ones that have sold out. It’s free: euroslam.run/#newsletter

If you’d like to read more about weather and racing, here’s where I ranked Europe’s 10 fastest half marathons for 2027:

Where Should You Run Your Next Half Marathon PB? I Ranked Europe’s 10 Fastest Courses for 2027

Which one would you pick? Tell me in the comments 👇

Good luck, and see you on the course!

After finishing the SuperHalfs in Berlin, my running friend Adrian and I needed a new challenge. So we looked at what other race series there are around Europe, and we found two: the Polish Crown, in Poland, and the Circuito Nacional de Running Plátano de Canarias, in Spain, with races in Seville, Barcelona, Madrid, Valencia and San Sebastián. We decided to take on the Polish one.

Adrian was working in Poland, so it was much more convenient for him, and for me, to fly to Poland. That’s why we chose the Polish Crown. Poland is also a lovely place to visit, with a lot of history and many beautiful cities, like Kraków and Gdańsk.

What the Polish Crown Is

The Polish Crown, officially Korona Polskich Półmaratonów, the Crown of Polish Half Marathons, has been organised since 2013 by Polskie Stowarzyszenie Biegów (PSB), a running association from Piła. To earn it, you have to finish at least 5 of the 11 half marathons on its list within one calendar year.

Everything starts on the PSB website, which is hard to find. From there, you get to the 2026 rules (in Polish), with the list of races. Then I created an account on Datasport, the registration site, and paid the fee, 125 zł in 2026. Once you’ve finished your five races, they send you the Crown.

The difficulty of the Polish Crown is that you have to run all five races in a single year. For a runner who’s just starting out, that could be a big challenge.

These were the 11 races in 2026. We had to choose five, and we picked the five biggest city races, in bold, each with a link to my report:

• Warsaw, 22 March
• Sobótka, 28 March
• Poznań, 19 April
• Białystok, 10 May
• Wrocław, night half marathon, 6 June
• Grodzisk Wielkopolski, 14 June
• Szczecin, 30 August
• Wałbrzych, 6 September
• Gniezno, 20 September
• Gdańsk, 27 September
• Kraków, 11 October

In your Datasport account, each race you finish should be marked automatically once the results are in. If one isn’t, you have to go in, add the result by hand, and ask for it to be validated.

Another important step is choosing where the Crown should be delivered. They send it to an InPost parcel locker in Poland, which you pick on a map in your account.

Why These Five

Warsaw was an easy choice: it’s a very big race, in Poland’s capital, easy to get to, and there’s plenty to see over a weekend.

Poznań, in April, was an easy choice too: it came a month after Warsaw, and it’s a historic city, so we didn’t have to think about it for long.

Wrocław, in June: I’d kept May for the Bucharest Half Marathon, so for June the choice was simple, between Wrocław and Grodzisk Wielkopolski. We chose Wrocław because it’s another old city, with plenty to see.

Gdańsk and Kraków, in the autumn: once we’d chosen the first three races, there was no doubt that the last two, to complete the series, had to be Poland’s most beautiful cities, Gdańsk and Kraków. The only challenge was that they’re just two weeks apart. But it turned out that if you run the first one more easily, you can push harder in the second.

How the Year Went

Warsaw, 1:42:08: the best start to a season since I started running, 4:38 faster than my first races of 2024 and 2025. It made me believe I could run under 1:40 later in the year.

Poznań, 1:47:04: four days after Warsaw, on my first easy run after a speed session, I strained my adductor. I came to Poznań still recovering, and I ran it too fast. It felt like a missed opportunity.

Wrocław, 2:03:59: the night race. At around km 10–11, I felt a slight pain in my left knee, and it got worse with every kilometre, until I had to walk almost the last 5 km. Afterwards, I found my mistake: I’d been pushing off the ground with my foot as hard as I could, which put a lot of pressure on my knee.

Gdańsk, 1:48:25: after 16 weeks without racing, I tried something new. I didn’t let my heart rate go above 167, and I consciously lifted my feet. I ran the same steady pace from start to finish, and the second 10 km were 13 seconds faster than the first. What I was missing was speed.

Kraków, 1:45:25: two weeks later, with the same low heart rate and the same foot lift, my speed started to come back, and that reassured me. It was my best time in the series after Warsaw.

In total: five races, 105.5 km, in 9:07:01.

The Crown

All along, I thought I’d get a real crown. I’d seen lots of photos of people running with crowns on their heads, and I’d even seen it with my own eyes at some races. So I waited eagerly for my crown, which in the end turned out to be a more festive medal, as you’ll see in the photo below.

Even so, it was a beautiful experience. I saw Poland, I saw a lot of history, and I have even more respect for the Polish people. They’re an example for my country to follow.

Final Thoughts

I warmly recommend the Polish Crown. You’ll get to discover a wonderful country, with a beautiful history and beautiful cities to visit. 👑

Running them yourself? Plan these races with euroslam.run: Warsaw Half Marathon → Poznań Half Marathon → Wrocław Night Half Marathon → Gdańsk Half Marathon → Kraków Half Marathon. Date, race-week weather and hotels near the start. EuroSlam is my own free side project. Some hotel links on the site earn me a small commission, at no extra cost to you.

Picking next year’s races? Once a month, EuroSlam sends one short email with the European races that open entry, the ballots coming up and the ones that have sold out. It’s free: euroslam.run/#newsletter

Originally published at therunningcat.blog on November 4, 2026.

21.1 km · 1:45:25 · 13°C, overcast

HR cap, with a tweak!

Gdańsk left me with a mystery: why had I lost speed but kept my endurance? While training with Norwegian Singles before Kraków, I tried to find the explanation, and it turned out to be nothing special. Because I trained through the summer, my heart rate was a bit higher, so training by heart rate meant I was actually running slower. That’s why I lost speed but gained endurance.

So after Gdańsk, I did only speed workouts to try to get it back before this race. Still, I had three half marathons in a row, one every two weeks, which is too close together to recover much in between. But I didn’t let that discourage me.

About the Race

The Kraków Half Marathon (PKO Cracovia Półmaraton Królewski, the Cracovia Royal Half Marathon) was the fifth and last race of my Polish Crown, and its 12th edition. The start is right next to TAURON Arena, on ul. Lema, and the finish is inside the arena itself, on the main floor.

The course follows the Vistula boulevards, goes through Podgórze and around Błonia, the huge city meadow, and passes the Main Square, Rynek Główny. The organisers don’t publish elevation figures, but my watch measured 66 m of climbing.

There’s a 3-hour time limit, and you have to pass 10 km within 90 minutes. The course records are 1:01:33 for men (Chichir, 2024) and 1:09:44 for women (Benedek), set this year.

This year, a record 16,148 runners finished, and in 2027 the race will host the Polish half marathon championships.

Planning and Arrival

I flew with LOT again, with a connection in Warsaw, and everything was flawless: no problems at all, and I arrived in Kraków without a hitch.

On a friend’s suggestion, I stayed near the centre again, in a place I really liked: Browar Lubicz Residence, a residential complex right next to the centre, a 10-minute walk away. Because it’s a residential complex, I had a two-room apartment, with plenty of space and everything I needed, which is just how I like to travel.

The downside was breakfast: I had to make it myself or go out and buy it at a café outside the complex. But that was fine too. I found a café where I could have an omelette and a really good breakfast.

Exploring the City

Kraków is an old city that escaped the destruction of the Second World War and has been very well preserved. In a way, it competes with Gdańsk for the title of the most beautiful city in Poland. I was convinced I’d like Gdańsk more, but now I’m not so sure. I couldn’t say which one I’d pick.

The centre of Kraków is very big, comparable to the other two I’ve seen so far, in Wrocław and Poznań. In the middle of it is the Cloth Hall (Sukiennice), often called the oldest shopping mall in Europe. It’s in quite good condition, and you can still visit it and buy things there.

What I liked most about Kraków is that there’s so much to see around it. I had the chance to visit four medieval castles on the Trail of the Eagles’ Nests (Szlak Orlich Gniazd): Bobolice, Mirów, Ogrodzieniec and Rabsztyn. Two of them, Bobolice and Mirów, have been restored and are open to visitors. It was a really beautiful trip.

Race Day

Right from the start, the organisation felt much better than in Gdańsk. Kraków is used to big races, and it showed.

The climbs seemed bigger (my watch agrees: 66 m of climbing, against 57 m in Gdańsk), but I found the course much better, because the climbs came in a few places instead of being spread over the whole course. Still, because the race finishes inside the arena, there’s a fairly big climb at the end. But in the end, it all went very well.

The weather was overcast, so I didn’t need a cap, and I ran really well. I didn’t even need a singlet and ran in a T-shirt. Because it was cool, I felt great in this race.

The finish inside the arena was sensational, against a bright blue backdrop, with lots of people clapping and whistling. I sprinted to the end of a really beautiful race.

As always, the race photo service took lots of photos of me, so I came away with plenty of souvenirs from this race, and photos I can use to analyse my running technique.

The Numbers

• Official time: 1:45:25
• 5 km splits (watch): 24:49 · 24:24 · 24:44 · 25:02
• First vs. second 10 km: 49:13 vs. 49:46, 33 s slower
• Heart rate: avg 166, max 178
• Cadence: 187 steps/min
• Weather: 13°C (55°F), real feel 15°C (59°F), overcast, 87% humidity, light drizzle, 9 km/h wind
• Polish Crown: Warsaw 1:42:08 · Poznań 1:47:04 · Wrocław 2:03:59 · Gdańsk 1:48:25 · Kraków 1:45:25

Final Thoughts

It was a race where I practised keeping my heart rate low again, but this time I also tried to consciously lift my foot more underneath me, without forcing it. That seems to have given me speed. I was surprised to see that, even though I trained for only one week (the first week after Gdańsk was for recovery), I managed to win back some of my speed. Somehow, that reassured me. It means that at my next race, Valencia, two weeks after Kraków, I’ll probably do even better.

Now I’m just waiting for my crown! I’ll wear it to my next 1:1 with our product manager. I promised him!

If you’d like to run it too, you can plan your Kraków Half Marathon with EuroSlam, my personal project: I turned my race-planning Google Sheet into a website.

Picking next year’s races? Once a month, EuroSlam sends one short email with the European races that open entry, the ballots coming up and the ones that have sold out. It’s free: euroslam.run/#newsletter

I’m a recreational runner with an office job, testing running science on my own legs. More about me.

Originally published at https://therunningcat.blog on October 18, 2026.

Whenever I fly, it’s a great opportunity to read a book or some interesting articles because, on the plane, I always have dedicated time — I can’t go anywhere, so the best thing I can do is read.

Recently, I went on a business trip to Seattle, and since the total flight time from where I live to Seattle was around 14 hours, I took advantage of it and read some interesting things. For me, it’s also a great chance to download a whole list of YouTube videos and watch them during the flight.

This time, I chose a series of articles about running and a few videos on the same topic.

To my surprise, I came across an article about a 2023 study titled “Progressive Daily Hopping Exercise Improves Running Economy in Amateur Runners: A Randomized and Controlled Trial.” Researchers had runners perform in-place jumps following a specific protocol and analyzed the impact on their performance.

Study Design

This was a randomized controlled trial with 34 amateur runners (average age: 29 ± 7 years, 27 males). Participants were divided into two groups: the Hopping Exercise Group (HE), which performed 5 minutes of daily double-legged hopping for six weeks, and the Control Group (CON), which continued their regular training without additional exercises.

Progressive Load

The duration of the hopping session started at 50 seconds per session in Week 1 and gradually increased to 150 seconds by Week 6. At the same time, rest periods between sets were progressively shortened to enhance adaptation.

Measurements (Before and After the Study)

• Running Economy (RE): Oxygen uptake per distance at 10 km/h, 12 km/h, and 14 km/h.
• VO₂peak (Maximal Oxygen Uptake): A measure of aerobic fitness.
• Respiratory Exchange Ratio (RER): Indicates fuel utilization (carbohydrates vs. fats).

Key Findings

1. Running Economy Improved at Higher Speeds (12 & 14 km/h)

• At 12 km/h, the running economy significantly improved (p < 0.05).
• At 14 km/h, the improvement was even greater (p < 0.05).
• No significant change was observed at 10 km/h.

2. No Change in VO₂peak

• The hopping exercise did not impact aerobic capacity (VO₂peak remained unchanged).

3. Increased Respiratory Exchange Ratio (RER)

• Higher RER at 12 km/h and 14 km/h: Suggests increased carbohydrate utilization at faster speeds.
• No change in RER at 10 km/h.

4. Mostly well tolerated

• Most runners handled the daily hopping without problems, but two reported pain (shin and ball of the foot). Build up slowly, and stop if something hurts.

Key Takeaways for Performance

• Running economy improved by ~2% at race-relevant speeds (12–14 km/h).
• No change at slower speeds (10 km/h): Benefit applies to moderate-to-fast running.
• Higher RER at 12 and 14 km/h: the body burned relatively more carbohydrate at faster speeds. The authors couldn’t explain why, so I wouldn’t read too much into it.
• VO₂max remained unchanged, meaning the gains come from efficiency, not aerobic capacity.

Conclusions

• Daily hopping exercises improve running economy at moderate-to-high speeds in amateur runners.
• The authors suspect stiffer Achilles tendons are behind it, but they didn’t measure it.
• Short, simple plyometric training (hopping) is effective and feasible, as an additional training component.
• No impact on VO₂peak, meaning it can be added without affecting endurance training.
• Potential applications: Could benefit endurance runners and team-sport athletes.

Practical Takeaways for Runners

• Adding 5 minutes of daily hopping can improve running efficiency at faster speeds.
• Useful for distance runners aiming for small but meaningful performance gains.
• The exercise is simple, requires no equipment, and can be done anywhere.
• For optimal benefits: Focus on minimal ground contact time, explosive movement, and gradual progression.

8-Week Daily Hopping Routine

Format

• Exercise: Double-legged hops
• Goal: Explosive jumps with minimal ground contact time
• Total Time: 5 minutes per session
• Rest Between Sets: Decreases progressively

Execution

1. Stand with feet hip-width apart.
2. Jump as high as possible, keeping knees relatively extended.
3. Land softly and immediately rebound.
4. Keep the core engaged to maintain proper posture.

Week-by-Week Progression

When to Perform the Routine

• Ideal Timing: After easy runs or before strength training.
• Avoid doing it before hard intervals or long runs to prevent fatigue.
• If fatigued, reduce the number of sets but maintain explosive quality.

Final Thoughts

• Running economy (RE) determines how efficiently you use oxygen at a given pace.
• Lower RE = more efficient running, using less oxygen to maintain the same speed.
• VO₂max is your aerobic ceiling, but RE determines how well you use that capacity.
• This small, simple hopping routine could be a game changer for endurance athletes.

Ready to test it on race day?

If you try the routine, you’ll want a fast course to test it on. I’ve been building a small personal project for exactly that: EuroSlam, a free calendar of half marathons and marathons across Europe, with the race-day weather, a speed score for every course and hotels near the start.

Find your next half marathon

(EuroSlam is my own free side project. Some hotel links on the site earn me a small commission, at no extra cost to you.)

I’ll tell the full story of how it started, from a hand-drawn map and a Google Sheet, in my next post.

Happy running, and tell me in the comments if you try the hopping routine!

Also on my blog: Does Hopping Make You a Faster Runner? What a 2023 Study Found

21.1 km · 1:48:25 · 15°C, sunny and humid

Four down, one to go!

I’ve started doing Norwegian Singles, training just under my threshold, at a heart rate of around 165. Gdańsk was the first race where I tried not to go above 167 and to consciously lift my feet for the whole race.

About the Race

The Gdańsk Half Marathon (PSG Garmin Półmaraton Gdańsk) was race number four of my Polish Crown. The organisers describe the course as flat and 100% asphalt. It’s PZLA certified, with a 3-hour time limit. My watch measured 57 m of climbing over the whole race.

This year, the start and finish moved to the streets in front of Polsat Plus Arena, the city’s football stadium. On the way, the course passes the Gdańsk Shipyard and the European Solidarity Centre, where Solidarność began, plus Oliwa Park, the Falowiec and the Baltic Opera.

This was also the biggest edition Gdańsk has organised so far. I think previous editions had under 10,000 runners, and this year they planned for 15,000. Before the race, I hoped the organisation would cope with that. We’ll see!

Elżbieta Glinka set a new Polish women’s record in the same race: 1:08:48, beating the old record of 1:09:18.

Planning and Arrival

I flew to Gdańsk with LOT, the Polish national airline. I’ve flown with them to most of my races in Poland, this year and in the past. It’s quite convenient, and Warsaw is an air hub that’s very well connected to the rest of Europe.

Even though it was a connecting flight, everything went smoothly, with no delays. I was impressed by LOT.

I stayed at the Scandic Gdańsk, right next to the main train station, Gdańsk Główny, and less than a kilometre from the city centre. That was very convenient, because it made it really easy to get into the centre and explore the city.

The hotel was fine and good value for money, and breakfast was decent too. For the first time before a race, I had toast with honey and bananas, and that was my whole breakfast.

The tram to Polsat Plus Arena leaves from right in front of the station, so right outside the hotel. Before race day, I got there very easily, in less than 20 minutes.

The expo was very small. Apart from the gels I always buy at expos, there wasn’t much to see. You can tell the organisers are still learning.

Exploring the City

Gdańsk is a very beautiful, historic city, full of interesting streets and architecture.

One street I have to mention is Mariacka Street, where you can buy amber jewellery. I walked along it two or three times and was fascinated by the beautiful amber pieces. I bought my wife a pair of earrings, and I’m sure she’ll love them when I give them to her.

I also really liked the Old Port on the Motława, with Żuraw, the Crane, Gdańsk’s famous medieval port crane.

From there, I took a boat cruise to Westerplatte, where Polish soldiers held out against the Germans in the first days of the Second World War.

I also visited the Museum of the Second World War, and it’s a very well-made museum.

Race Day

On race day, though, we couldn’t get on the tram. Unfortunately, the organisers hadn’t arranged any extra trams, and the last one that could get us there in time came about 50 minutes before the start, packed full of runners.

So we had to order an Uber and rush to the start. From where the Uber dropped us off, we ran to the bag drop to leave our clothes, and from there straight to the start. There was no way to warm up properly, so I started this race completely cold.

This was where the organisation started to show its weak spots, with the number of runners almost doubling.

By my standards, race day was quite warm. I ran in a singlet and a cap, and I was still hot. That was completely unexpected, since Gdańsk is in the north and the climate is generally cool. But compared with other races where I ran in full sun, the conditions here were OK.

The course had a lot of climbs, and the hard part was that the ups and downs kept coming for almost the entire race. I expected Gdańsk to be a fast race, but the climbs and descents wore me out very quickly and turned the race into a real test.

I put my plan into action right from the start. After the first kilometre, when I hit the first climb, and with the heat, I decided not to go above 167, except maybe in the last few kilometres. Even though it was hot, watching my heart rate meant I could run a consistent race from start to finish.

My new technique of consciously lifting my feet helped on the climbs too: even though they were hard, I managed to keep a decent pace and feel good.

And my watch agrees: my heart rate didn’t go above 167 for the first 14 km, every kilometre was between 4:57 and 5:20, and I ran the second 10 km 13 seconds faster than the first.

Towards the end, the course got quite crowded and difficult. The finish section started before the arena with a hard climb over a bridge, then I sped up on the way down, and there were a few turns around the stadium. I guess the organisers needed a few dozen more metres to make up the official distance.

We also ran through the arena itself, which was a really great feeling. But even with all the adrenaline, it was impossible to overtake in there. Then we came back out, and the finish line was right next to the arena.

All in all, I’m happy with this race: it was controlled, and it’s one I’ll recover from very quickly.

The unpleasant surprise came after the race, when we couldn’t get back to the hotel. Taking the tram was impossible, and so was calling an Uber, because there was no phone signal. I’m not sure whether that was because there were so many runners in the area that you couldn’t get onto the network, or because the stadium is quite isolated. Either way, we had to run 3 km back to the hotel.

At least it meant I hit the 45 km of weekly mileage I wanted!

The Numbers

• Official time: 1:48:25
• 5 km splits (watch): 25:29 · 25:42 · 25:23 · 25:35
• First vs. second 10 km: 51:11 vs. 50:58, 13 s faster
• Heart rate: avg 165, max 183
• Cadence: 188 steps/min
• Weather: 15°C (59°F), real feel 22°C (72°F), sunny, 80% humidity, almost no wind
• Polish Crown so far: Warsaw 1:42:08 · Poznań 1:47:04 · Wrocław 2:03:59 · Gdańsk 1:48:25

Final Thoughts

It was a special race for me, one where I ran the same steady pace from start to finish. What I was missing was speed. I’ll spend a few hours with AI trying to understand why I still have the endurance but not the speed. For now, it remains a mystery.

Judging by the crowds at the end, the organisers still have a lot to learn before this becomes a race with an international reputation, like others I’ve run, such as Valencia, Berlin or Paris.

Running it yourself? Plan this race with euroslam.run → Date, race-week weather and hotels near the start. EuroSlam is my own free side project. Some hotel links on the site earn me a small commission, at no extra cost to you.

Picking next year’s races? Once a month, EuroSlam sends one short email with the European races that open entry, the ballots coming up and the ones that have sold out. It’s free: euroslam.run/#newsletter

I’m a recreational runner with an office job, testing running science on my own legs. More about me.

Originally published at https://therunningcat.blog on October 4, 2026.

21.1 km · 2:03:59 · 18°C, at night

Three down, two to go!

For the third race of the Polish Crown, we wanted a race in June, and the only one that really appealed to us was Wrocław. It was my first half marathon at night. Until then, my only night race had been a 10K, and that one started at around 7 or 8 PM, not at 10.

I also have to admit something: after reading too much about running form, I had tried to change my running technique before this race. That turned out to be a mistake, both during the race and after it.

About the Race

The Wrocław Night Half Marathon (Tarczyński Nocny Wrocław Półmaraton) was race number three of my Polish Crown, and its 12th edition. As the name says, it runs at night: the start was at 22:00 on a Saturday in June.

This year’s course was new. The start and finish moved to Tarczyński Arena, the city’s football stadium: you start on al. Śląska and finish on the stadium pitch. On the way, the course goes through the Old Town, crosses the Grunwaldzki and Młyński bridges with views of Ostrów Tumski, and passes the lit-up university bridges. The organisers called it a “new, faster” course, and it’s certified by AIMS, World Athletics and PZLA. My watch measured 38 m of climbing.

It’s a huge race. The first 22,000 places sold out in 36 hours, 26,066 runners registered in the end, and 21,807 crossed the finish line.

Planning and Arrival

To get to Wrocław, I flew all the way with LOT.

I stayed at the Wyndham Wrocław Old Town, in one of the 3-star rooms (they have 4-star ones too). Being right in the centre, it was very convenient. Getting to Tarczyński Arena was quick too: the tram took me there in 20 minutes. Trams in Poland are very convenient: instead of buying a ticket, you can pay by card right on the tram, which is what I did.

Exploring the City

I don’t know which is bigger, Wrocław or Poznań, but the two are very similar. The centres felt almost identical, with beautiful old architecture and lots of places to sit, talk and have a beer. It’s definitely a beautiful city. I also climbed the tower of St Elizabeth’s Church, for a view over the rooftops of the Old Town, and took a boat cruise on the Odra. You can tell which photos I took from the boat!

Wrocław is full of little dwarfs (krasnale), placed all over the city. There are several hundred of them, like the ones in these photos.

I also visited the University of Wrocław, which looks really beautiful. Its main building is baroque, from the 18th century, and it’s hard to believe it came through the communist years looking this good.

I also visited the Museum of Illusions. It’s small, but it’s good for the day before a race, because it doesn’t tire you out. I wouldn’t go out of my way for it, but if you have nothing else planned, it’s fine.

Race Day

Another stadium start! Like Warsaw, Wrocław starts the race at the city’s stadium, and I think it’s a very convenient way to organise a race.

Being a night race, though, it had a surprise in store: a show of lit-up drones that wrote all kinds of messages and drew pictures in the sky. I had no idea you could actually draw with drones!

The race started after dark, and the start area was quite crowded: we struggled to find a spot where we could warm up. But unlike some other races, I can tell you the organisation was good. There were plenty of trams, so we got there in time, and they weren’t packed.

I think the only downside was that we lined up in the start area quite a long time before the start, so we spent a lot of time on our feet. I could still feel it in my legs when the race started, but I quickly forgot about it, because the whole race was a light show. My adrenaline shot up, and I set off determined to run a good time.

I expected a flat race, with no climbs or descents. The only catch, I thought, was that it was at night, but I figured the city would still be well lit.

In the first 2 km, there’s a stretch with a light show: spotlights set up on the grass, pointing upwards. It looks great, but it makes the asphalt very hard to see. I ran that part a little scared, lifting my feet as high as I could, but that was all, because there was nothing on the road to trip over.

Before this race, I had watched Fredrik Zillén’s online course on running technique, and I was trying to put what I’d learned into practice.

Still, I started the race fairly well, and it looked like it would be a good one, especially as I was holding a steady pace. But at around km 10–11, I felt a slight pain in my left knee. It got worse with every kilometre, and at one point I was afraid to stop at an aid station, because I didn’t think I’d be able to get going again.

That’s exactly what happened at km 15: after I drank some water, it was very hard to pick up speed again. From then on, I ran slower and slower, until I had to stop running altogether. I think I walked from about km 17 to the finish.

If it hadn’t been for the Polish Crown, I would have pulled out of the race. But I had to finish it no matter what, so I did the maths: I would still get a decent time and finish well within the official time limit.

At the end, because the finish was inside the arena and the atmosphere was great, I forced myself to run the last 200 metres, so that I’d appear in the photos running, not walking. That’s exactly what happened, though it didn’t do much for my time.

The Numbers

• Official time: 2:03:59
• 5 km splits (watch): 24:59 · 25:09 · 26:02 · 36:07
• First vs. second 10 km: 50:08 vs. 1:02:09
• Km 16 to 21: 5:33 · 6:08 · 6:35 · 8:42 · 9:09 · 8:52
• Heart rate: avg 158, max 170
• Cadence: about 184 steps/min running, 143 walking
• Weather: 18°C (64°F), real feel 18°C (64°F), overcast, 60% humidity, after dark
• Polish Crown so far: Warsaw 1:42:08 · Poznań 1:47:04 · Wrocław 2:03:59

Final Thoughts

I was surprised that, even though I couldn’t run for almost the last 5 km and had to walk, I still finished in 2:03. I find that remarkable.

Even though the start and finish area was very crowded, I think the organisation was good overall, especially because after the race I found a tram very easily. I didn’t have to squeeze in with other runners to get back to the hotel: the tram was comfortably full, not packed.

I also loved the atmosphere. It felt like an evening celebration, with lots of people coming out to watch the race and to run it. It’s a big race and a beautiful one, and I recommend it.

Afterwards

Obviously, the knee problem took me by surprise, so I started reading more and more to find out what I had done wrong. In the end, I found my big mistake. I had misunderstood part of the course and was pushing off the ground with my foot as hard as I could, which put a lot of pressure on my knee.

It’s wrong anyway: the longer your foot stays on the ground while you push, the longer your ground contact time. So in reality, it made me slower, and it caused my injury.

Running it yourself? Plan this race with euroslam.run → Date, race-week weather and hotels near the start. EuroSlam is my own free side project. Some hotel links on the site earn me a small commission, at no extra cost to you.

Picking next year’s races? Once a month, EuroSlam sends one short email with the European races that open entry, the ballots coming up and the ones that have sold out. It’s free: euroslam.run/#newsletter

I’m a recreational runner with an office job, testing running science on my own legs. More about me.

Originally published at https://therunningcat.blog on June 13, 2026.

21.1 km · 1:47:04 · 13°C

Two down, three to go!

Warsaw had gone very well: I finished in 1:42:08, less than a minute off my personal best. Poznań is known as a fast race, so I told myself I had to train even harder and set a personal best there.

So four days after Warsaw, on the Thursday, I went out for a speed session: 3 × 2 km. On my first easy run after that session, I strained my adductor. I came to Poznań four weeks after Warsaw, still recovering, but I went for a personal best anyway.

About the Race

The Poznań Half Marathon (PKO Poznań Półmaraton) was race number two of my Polish Crown, and its 18th edition. The start was at 9:00 on a Sunday in April, an hour earlier than in previous years.

This year’s course was new. You start on ul. Roosevelta, next to the East Hall of the Poznań International Fair (MTP), and run one big loop through Łazarz and Park Wilsona. For the first time, the course also goes through the Enea Stadion, the city’s football stadium. The old climb on Roosevelta near the finish is gone, and you finish back at the fair grounds. The course is certified by AIMS, World Athletics and PZLA, and my watch measured 45 m of climbing.

It was a record year: 13,500 runners crossed the finish line.

Planning and Arrival

To get to Poznań, I flew with LOT, but only as far as Warsaw, and decided to take the train from there. At first, it seemed like a good idea. But after a race, a train journey isn’t exactly what you want. You want to lie down in the lounge, get on the plane, and that’s it, not run after trains. Still, I learned something new: a connecting flight beats the train.

At the expo, I saw the stand of the 49th Bieg Lechitów, the oldest half marathon in Poland, held every year since 1978. It runs from Ostrów Lednicki, an island on Lake Lednica, to Gniezno, Poland’s first capital. The start is there because, in the year 1000, Emperor Otto III set off from Ostrów Lednicki on foot to St Adalbert’s tomb in Gniezno. The people promoting it were dressed as kings, and it looked like a really nice race. One of them ran in Poznań the next day, dressed as a knight, and finished in a very good time: around 1:31, by my estimate.

Exploring the City

Poznań is smaller than Warsaw, but it feels much older and more traditional, with lots of old buildings. In Warsaw, there isn’t much to see, but in Poznań there were plenty of old places to visit, and I liked them. It reminded me of Sibiu, a city in Romania.

The heart of the city is the Old Market Square (Stary Rynek), lined with colourful merchants’ houses, with the Renaissance town hall in the middle. Every day at noon, two mechanical goats come out above the town hall clock and butt heads twelve times. The last two photos are from the evening.

Not far from there, on Plac Wolności, is the Raczyński Library, with its long row of columns.

I also walked through the Imperial District, around the Imperial Castle and the buildings of Adam Mickiewicz University. It was built in the early 1900s, when Poznań was part of Germany. In front of the castle, I found a monument to the three students of the University of Poznań who broke Enigma, the cipher machine Nazi Germany used in the Second World War: Marian Rejewski, Jerzy Różycki and Henryk Zygalski.

I also visited Poznań Cathedral, on Ostrów Tumski, the island where the city began. It’s the oldest cathedral in Poland, and the first rulers of Poland, Mieszko I and Bolesław the Brave, were buried there. On one wall, there’s a copy of the Sword of St Peter. Legend says it’s the sword Peter used to cut off a servant’s ear in the Garden of Gethsemane. The original is kept in the Archdiocesan Museum.

Race Day

The weather on race day was good, good for a personal best. Maybe that tempted me too, and I started too fast.

The start felt a bit crowded, but the course was quite flat, with fairly few turns. And I think this was the race where I ran my first kilometres the fastest: the first 4 km were all between 4:36 and 4:41, faster than the 4:47 per km I needed for a personal best. For a long time, I was even ahead of the 1:40 pacers, which shows how fast I started.

After Warsaw, I had also watched a course on running technique, and I decided to try it out here. Basically, I pushed off harder with my back leg to make my stride longer. I don’t know if that’s why I ran the first kilometres much too fast, but it definitely tired me out much more than in Warsaw, and my heart rate was much higher too: in the first 8 km, it was 171–173, against 167–169 in Warsaw at about the same pace. That could also be the weather, though: it was a few degrees warmer than in Warsaw.

Of course, at around km 8, I felt I couldn’t hold the pace any more. Once I got tired, my technique fell apart, and in the last few kilometres I was running at 5:20 per km.

The adductor didn’t hurt. It felt tired, but it never told me to stop. Still, I don’t think I was 100% recovered, so I shouldn’t have run this race so fast.

The Numbers

• Official time: 1:47:04
• 5 km splits (watch): 23:24 · 24:43 · 25:59 · 26:23
• First vs. second 10 km: 48:07 vs. 52:22
• Pace: 4:36 at km 2, 5:06 at km 10, 5:20 at km 19
• Heart rate: avg 170, max 180, and 168–173 from km 2 to the finish
• Cadence: about 187 steps/min
• Weather: 13°C (55°F) at the start, 15–17°C (59–63°F) by the finish, overcast, 51–56% humidity, almost no wind
• Polish Crown so far: Warsaw 1:42:08 · Poznań 1:47:04

Final Thoughts

It feels like a missed opportunity. I should have trained specifically for Poznań, not for Warsaw, and set my personal best here.

I’m worried this will ruin my next race, although it’s still a month away, so maybe I’ll have time to recover fully.

Even so, I recommend this race. If you’re doing the Polish Crown, it’s one of the best races for a fast time.

Running it yourself? Plan this race with euroslam.run → Date, race-week weather and hotels near the start. EuroSlam is my own free side project. Some hotel links on the site earn me a small commission, at no extra cost to you.

Picking next year’s races? Once a month, EuroSlam sends one short email with the European races that open entry, the ballots coming up and the ones that have sold out. It’s free: euroslam.run/#newsletter

I’m a recreational runner with an office job, testing running science on my own legs. More about me.

Originally published at https://therunningcat.blog on April 26, 2026.