A great (but very hot) 10 km race around the Lotus Test Track. Find out how the heat affected my performance.
A bit late on this race report, but better late than never…
On 16th June, and unusually for a Friday, I ran the Lotus Test Track 10k. As per my pre-race article, this was hosted by Harling Athletics Club, this was a 10 km race around the test circuit located at the Group Lotus headquarters near Hethel, Norfolk, UK. It was race number 8 of the 2023 Sportlink Grand Prix.
The full test-track circuit is 2.2 miles (~ 3.5 km), but the race was configured to run four times around a 2.5 km lap. It is a flat circuit, however the forecast 21° C was not looking entirely favourable for a fast run time. With the race beginning at 19:00, my hope was that the heat of the day would be rapidly dissipating and it would be cooler than forecast. I was wrong….
The sane person in me would have adjusted my racing strategy.
Throughout the drive to the event, my car read 26° C, dropping a degree upon arrival. At 18:45 I completed my final preparations and left the car, with its temperature reading at 24° C. It was going to be a hot one, with a clear sky and beating sun. The sane person in me would have adjusted my racing strategy, i.e. aim for a slower time than originally planned. However, I was only here to do one thing – attempt a 40 minute PB. If I failed in that due to the heat, so be it.
My Race
I quickly got into my stride and knew I was just faster than my target 4:00 min/km pace
The starting corral was quite narrow and I positioned myself about 10 metres from the start line. After a short pre-race speech and countdown, we were off. I had positioned myself well as the runners in front went off faster than me and the runners behind were not jostling to overtake. Consequently I quickly got into my stride and knew I was just faster than my target 4:00 min/km pace. A quick glance at my watch displaying 3:53 gave confidence to my subjective calculation, and I allowed myself to relax and ease off a little. I was soon around the first 180° (but very gentle) bend and could see the 1 km marker ahead. I crossed it, 3 minutes 55 seconds.
At 1.6 km the chicanes were another story…
At 1.35 km there was the first of many chicanes. It was relatively benign and had little effect on my pace. At 1.6 km the chicanes were another story, with 4 turns, 3 of which were sharp 180s. As I exited the last of the set, I could see the 2 km marker. I put some effort in to compensate for the recent twists and turns, reaching the marker at 7:50 – another 3:50 min/km split.
As soon as the 2 km marker was behind me, it was another 180° turn. And then another. I was now approaching the 2.5 km point and the end of my first lap. I knew that with all the decelerations and accelerations due to the chicanes, that tonight was not going to be easy. And I could already start to feel the impact of the heat.
My head and hands were throbbing with the heat
Knowing that I still had 3 laps to do and that I was 10 seconds ahead, I allowed myself to ease off a fraction. I reached 3 km at a pace 4:03 min/km. By the time I arrived at the 4km point in a similar pace of 4:02, it was the turn of the chicanes again. Turn after turn of… decelerate… accelerate… As I left them behind and ran to complete my second lap my legs were feeling their effects, made ten times worse by the heat. I crossed the lap point. 5 kilometres done, half way, bang on 20 minutes. My head was beginning to pulse with the heat.
The heat and knowing that I still had 2 laps to go, made kilometre 6 extremely tough. I completed it in 4:11 min/km, and I was 11 seconds behind schedule. I kept telling myself ‘only 4 kilometres to go’, and forced my legs to pick up the pace. I completed kilometre 7 in a time of 4:06. I was now 17 seconds behind, and worse of all back in the chicanes. My legs were beginning to fail me and my hands now starting to throb in unison with my head. I crossed the lap marker with very heavy legs.
It was with great relief that I crossed the finish line
My final lap. I was behind schedule and knew that the 40 minute time was beyond my grasp. It was now an issue of ‘damage limitation’ and finishing as quickly as possible to put an end to my pain. As such my last 3 kilometres were each ran at about 4:15 min/km pace – not too bad, considering how I felt. It was with great relief that I crossed the finish line. Official time, 41:04.
Analysis
My 3rd fastest 10 km performance ever
41:04 may have been 64 seconds (2.7%) over my target time, but it is still my 3rd fastest 10 km performance ever, and around 4 minutes faster than I was running 7 months ago. So not all bad.
Below is a table illustrating the various predictions for my race, along with their error from my actual performance.
| Algorithm | Predicted Pace (min/km) | Predicted Time (mm:ss) | Error (seconds) | Error (percent) |
| Riegel (6 min Assessment) | 4:27 | 46:10 | + 310 | + 12.6 % |
| Riegel (3.2 km Assessment) | 4:20 | 43:20 | + 140 | + 5.7 % |
| Running Watch | 4:12 | 42:04 | + 64 | + 2.6 % |
| Athlete Data Analysis Platform | 4:11 | 41:50 | + 50 | + 2.0 % |
| Riegel (10 mile Race) | 4:01 | 40:10 | – 50 | – 2.0 % |
| TrainAsONE | 4:01 | 40:05 | – 55 | – 2.2 % |
Once again, the Riegel estimates based upon my assessment runs were highly inaccurate, predicting much slower finishing times than performed. All the other predictions had an error of around plus or minus 2 %.
Each prediction was assuming ‘ideal racing conditions’
It should be noted that each prediction was assuming ‘ideal racing conditions’. In general this means a flat and fast course at a temperature of between 10 to 16° C. For this race, whilst it was a flat course, as illustrated above there were many tight turns to hamper speed, and it was raced under hot conditions.
When I returned to my car after the race, it was still reading 22° C. Consequently, one can assume that it was an average of 23° C during the race. Adjusting for this temperature, one would estimate that under cooler conditions I would have ran a time of 40:10, i.e. 54 seconds quicker.
…taking it down to 40 minutes dead… My target time!
I would go further to say that there were five 180° turns on each lap. That’s a total of 20, and I would estimate that they cost around half a second each. This would take another 10 seconds off my time, taking it down to 40 minutes dead… My target time!
The temperature adjustment I used in the above calculation is from TrainAsONE. Out of interest, I also ran the numbers through a couple of online calculators. These gave me a much smaller difference at 16° C. For my 41:04 at 23° C, they were estimating a time of between 40:36 and 40:44 at 16° C, i.e. a 20 to 28 second difference.
Consequently, I thought that it would be interesting to collate the published data for the runners in my racing category and compared their recent best 10 km race time against their result in this race. The data is presented below.
| Recent Best 10 km Time (h:mm:ss) | Lotus Test Track 10k Time (h:mm:ss) | Difference (mm:ss) |
| 0:36:41 | 0:36:55 | 00:14 |
| 0:44:06 | 0:47:45 | 03:39 |
| 0:42:01 | 0:42:41 | 00:40 |
| 0:36:59 | 0:37:27 | 00:28 |
| 0:44:59 | 0:48:06 | 03:07 |
| 0:43:45 | 0:46:25 | 02:40 |
| 0:37:17 | 0:38:19 | 01:02 |
| 0:41:06 | 0:41:50 | 00:44 |
| 0:54:24 | 0:54:07 | – 00:17 |
| 0:50:15 | 0:51:00 | 00:45 |
| 0:46:35 | 1:00:36 | 14:01 |
| 0:37:16 | 0:36:50 | – 00:26 |
| 0:42:00 | 0:42:31 | 00:31 |
| 0:46: 48 | 0:43:39 | – 03:09 |
| 0:43:54 | 0:47:07 | 03:13 |
| 0:44:45 | 0:47:25 | 02:40 |
The table illustrates that there is quite a big range in differences, from -189 seconds to +219 seconds, with a mean of +112 seconds. It’s not a large sample and there are some obvious outliers. Consequently, the median is probably a better indicator of the effect of course conditions. The median for the data is +44 seconds.
My recent best (my all time personal best!) is 40:20. That’s + 44 seconds. Not a bad fit…
Finishing Up
Naturally it was disappointing not to obtain my elusive 40 minute time, but this race nicely demonstrates the effects of heat (and chicanes) on performance – both for me and other similar runners.
I ran the first 5 km in 20 minutes. Something I have not achieved in over 15 years
Maybe I could have ran the race smarter (i.e. set out at a slower pace) to have obtained a slightly quicker time. But I am positive this would only had squeezed out 5 or maybe 10 seconds. And I know I can run sub 41 minutes, so where would the fun in that be. 😀
The additional positive to come out of my approach is that I ran the first 5 km in 20 minutes. Something I have not achieved in over 15 years. So I’m happy with that.
My next race is the ‘Humpty Dumpty 10k’ this coming Sunday, and so I’ll be having another attempt. The current forecast is 18° C…
As ever, a big thank you to the race organisers, volunteers and all those involved. A great race. Thank you.
Till next time.
