UTMB 2022: How Did GPS Watches Compare?
Posted on August 31 2022
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We found this great blog written in French comparing the performance of this years top UTMB runners GPS watches. We think you might also interested and so translated it to English for your quick reference.
Much credit to Mon Comparateur for putting this together.
Original Blog Click 👉🏻 HERE:
Each year, the UTMB offers a huge opportunity for GPS watch brands (among others) to show what they are capable of.
Each brand highlights the results of their sponsored athletes. This year, Coros did very well, winning the first 2 places in the UTMB, with a total of 4 men out of the first 10. I had fun studying how the GPS watches used on the UTMB 2022 performed.
Do you want to know how many use an Enduro 2 or a Vertix 2? If women prefer smaller watches? How does the accuracy of GPS tracking compare?
This is my analysis.
What was my methodology?
For starters, there are brand-sponsored athletes such as Kilian Jornet who moved this year from Suunto to Coros which caused a stir. We know he runs with a Coros Apex Pro. We also know the first woman, Katie Schide, is sponsored by Garmin.
Then there are those who talk about it on social networks, like Mathieu Blanchard who also runs with a Coros Apex Pro.
But hey, if we only proceeded like that, we would not progress very quickly, so what are the alternatives?
What is the biggest sports database? Strava of course.
When you view a sports activity on Strava, in the preview, the model of the GPS watch usually appears. The difficulty is that Strava prohibits the downloading and use of its data to create statistics on a large scale. It's a shame, because it would have been interesting to do the usage statistics on this kind of race (or Kona's Ironman), just to get a good idea of the market at the moment.
So we did this by hand. Well, I limited myself to the first 30 men and the first 10 women, plus a few specific profiles (to get Polar in particular). On this sample there are still blanks, because some do not have a Strava account, or it is private, but this is what we found.
Let’s first look at the Men
GPS watches for trail runners on the UTMB 2022
For this 2022 edition of the UTMB, Coros is the big winner. It's impressive to see the place that this young brand has made in a few years on the trail running market.
That said, this analysis is only focused on the elites and is distorted due to sponsorship. It’s very likely that something like 80% of amateurs wear a Garmin…
Did you expect to see Enduro 2s and Vertix 2s everywhere?
After all, these are the 2 GPS watches with the longest battery life, perfect for ultra trail running, right?
Well no… I looked at the first 100 and there was 1 Enduro and zero Enduro 2 (probably too recent). It must also be said that for these elites, the UTMB is somewhat shorter in time than for the majority of participants so they don't necessarily need a huge GPS watch with extremely long battery life.
On the contrary, they favor lightness. This is what made Kilian Jornet favor the Apex Pro (40 hours of autonomy and cartography) when Coros presented its entire range to him. He also changed the strap for a nylon one to gain a few more grams. However, Kilian also uses the Vertix 2 to measure his heart rate variability. Very interesting to see how Kilian Jornet uses science and his GPS cardio watch to train.
The outlier is Jim Walmsey with his Wahoo Elemnt Rival.
Perhaps not a huge surprise as this year, Wahoo was sponsoring the UTMB. So a great catch for them to attract Jim Walmsley. The Element Rival was therefore the official timer on the finish line, just under the arch. As a reminder, the Garmin Fenix 6 held this place 3 years ago.
Note the presence of a good old Suunto Ambit3 Peak in the list. A GPS watch that has demonstrated its reliability and GPS precision (even without the dual frequency), sold at the time for €299. It leaves you wondering… Further down the rankings, I even found an Ambit3 Run, a GPS watch without alti baro.
GPS watches for Women trail runners on the UTMB 2022
For a long time, women trail runners struggled to find a GPS watch that was both small and had good battery life. Even a few years ago, all GPS watches were big, and all small watches were more entry-level, with fewer sensors and sports features.
Fortunately, technological progress has greatly improved performance in terms of autonomy (more efficient batteries and less energy-consuming electronic components).
At the same time, some brands have started to offer their GPS watches in 2 or 3 formats, with the same level of functionality.
It is therefore hardly surprising to find more Garmin on the wrist of women in UTMB 2022. The Fenix 7S with 37 hours of autonomy (+9 with solar charging) for a bezel size of 42mm. They opt for the Suunto 9 Peak (smaller than the 9 Baro) and Coros for the Apex (smaller than the Apex Pro).
GPS Accuracy Comparison
When analyzing the GPS tracking recorded by the GPS watches of these champions it must be kept in mind that we do not know the different settings used by each. The Fenix 7 Sapphire, Forerunner 955 and Vertix 2 are not necessarily being used in dual frequency GNSS multi mode.
Nevertheless, I will show you some interesting details.
It only took me a few kilometers, barely out of Chamonix, to identify the GPS track of the Fenix 6X. Look at the orange trace, it is worse than the others in the turns. The Fenix 5 and 6 immediately have poor GPS accuracy as soon as you pass under trees.
As soon as the trail rises in the mountains, this problem is even more visible.
At the Contamines supply point, we see 2 things:
- Rod Farvard went to pee
- Blue and green traces made balls of yarn
These balls of wool are a typical behavior of Garmins when hiking. More generally, each time you take a break without cutting off the GPS recording (that's why you notice it more when hiking than when running). We stop but even when stopped, the watch continues to record small movements around our position (GPS errors) which in the end will distort the calculation of total distance.
To avoid this problem at refreshments, I explained several adjustment tips in a video (published 3 weeks before the UTMB).
The pink trace does not have this problem. I deduce that the Fenix 7X Sapphire may be in dual frequency multi GNSS mode (my tests showed that this setting also solved this problem). Or else Thomas Evans and Maxime Grenot passed almost without stopping at this aid station.
A little further into the mountains, we see once again that the tracks of the latest generation GPS watches (Forerunner 955, Fenix 7 and Fenix 7X) are much better than those of the Fenix 6X.
Refueling of Courmayeur. Thomas Evans' Fenix 7X is also starting to make balls. It is therefore probably not in dual frequency multi GNSS. The Forerunner 955 totally freaked out. Another proof, if it were needed, of the interest of cutting off the GPS during refreshments. If this ever happens to you, I have published a tutorial to explain how to correct this kind of GPX trace afterwards with GPX.studio.
Just for the record, this is the moment when Rod Farvard obviously took a wrong turn.
Overall, the Garmins do a group assessment of around 175.3 – 175.5km. The Forerunner 955 displays 175.9, probably due to the big GPS error of the Courmayeur ravito. And finally, despite the multitude of GPS errors, the Fenix 6X manages to give us the correct total distance (the errors are canceled).
In terms of elevation, all Garmin GPS watches display an arrival altitude almost equal to that of departure. But the d+ varies between 9700 and 9900m, with a tendency towards 9700 (and knock, now you can trick your colleagues who have finished the UTMB by proving to them that they have not done 10,000m of d+). At this stage, 200m is not much.
The GPS tracks of the Coros remain fairly accurate at the Contamines refueling point. We could almost point to the location of the table at which the trail runners stopped. Difficult to say if Jimmy Elam made a small turn or if it is a GPS error.
All GPS tracks are fairly close to each other. The least precise is that of Kilian Jornet!
From a distance, it could look like a big GPS error. But it still seemed curious to me that 2 GPS watches suffered the same error in the same place. So I zoomed in and changed the basemap. We then realize that Mathieu Blanchard and Santos Gabriel Rueda simply cut on the descent (they had to have confidence in their quadriceps). And I remember very well during the Live transmission
Otherwise, good general GPS accuracy.
Mathieu Blanchard still cuts the turns downhill.
Have I already told you that Kilian Jornet's Apex Pro made a lot of GPS errors?
Overall, for the measurement of the total distance, the Coros make a less grouped assessment. A few are placed 175.5km or so (the same grouping as Garmin). The 2 extremes are at 174 and 177. But we must not forget that if Mathieu Blanchard's Apex Pro displays 174.3km instead of 175.5, it is also because he cut turns on the descents . Despite his many errors, Kilian Jornet's Apex Pro manages to get the correct final distance (the errors cancel each other out).
In terms of elevation, the precision seems much better, with watches that all agree around 9700 – 9750m of d+.
Very quickly, the GPS track of the Suunto 9 shows many GPS errors.
The Suunto GPS watches manage the passage to the Les Contamines refueling station very well, there is no noticeable difference. We can clearly see Juuso Simparen going to the toilet.
Afterwards, in some climbs, the GPS tracks are sometimes very irregular. Can the multiplication of these small errors explain the error of 5-6km on the total distance? It still seems like a lot to me.
This is a problem really specific to certain climbs because on the descents the GPS tracks are smooth.
Just before Champey, the Green Cap Suunto 9 Baro began to trace straight lines in the turns. I don't think it's related to the FusedTrack algorithm because on this downhill section, it's an algorithm that should have worked well.
The Ambit3 Peak is unanimously recognized as a particularly precise GPS watch.
However, on the ravito (here Champey-Lac), it loses the GPS like the other GPS watches (normal). Except that afterwards, it takes several kilometers to re-attach the GPS, which results in an erroneous GPS track.
The Suunto 9 Baro also went into a bit of a spin. Here, the Suunto 9 Peak, the most recent GPS watches, performed best.
Here is the moment when the Ambit3 Peak has reached the end of its battery. Yes, in maximum GPS precision, the Ambit3 Peak only has a range of 20 hours (which was already great at the time). Over time, the battery has lost its capacity over recharging and on the UTMB 2022, it only lasted 16:43. Thibault Marquet then took out his smartphone to record the end of his race with the Strava app.
Barely further, here is the moment when the track of one of the Suunto 9 Peak stops. The Suunto 9 Peak is given for 25 hours of battery life.
However, if certain features (route tracking, various alerts) are used, or you have made incorrect settings (leaving the backlight activated) the actual battery life will be lower than this theoretical value.
Here, I think Juuso Simpanen realized this and switched to a power management mode in which the GPS is muted. It allowed him to save the battery and go to the finish: the time and the total elevation are correct but he does not have the GPS track to the end.
Overall, can the irregularity of the GPS tracks in certain climbs explain the total distances of more than 180km where the GPS watches of others mark suggest that there was rather 175.5km? The analysis of the GPX Polar traces made me think of another explanation. See at the end of the Polar tracks.
Personally, I'm disappointed that no Suunto athlete used Snap to route. It is an algo which makes it possible to ensure, during a race, that the watch will always indicate the correct distance. It's a shame not to use it anyway... In terms of elevation, the Suunto readings coincide with the others, in the 9800m. Finally, it is the Suunto 9 Peak by Juuso Simpanen, less affected by GPS errors, which measures the drop closest to the Coros (the watch then only relies on its alti baro).
I dug all the way to the 35th man to find Polar's first GPS watch, a Grit X Pro. Frankly, the GPS track is very clean.
So I'm puzzled. It displays 182.4km and yet I see no problem explaining these 5-6km too much (if we refer to the majority readings of other watches).
Ah yes, there, Roberto Mastrotto must have lost something and went back to look for it. But hey, according to the scale it must have been 2 x 100m. That doesn't explain the 5-6km difference.
The only explanation I can see for the Polar/Suunto having such a different average than the Garmin/Coros for no apparent reason is that I pulled this data from Strava.
These are not the original GPX tracks taken from the watches. Strava is known to redo its own small calculations from the files it receives (it is not uncommon to observe differences between the Strava data and those of the application of your GPS watch).
We understand everything by going to read the explanations of the Strava support on the calculation of the total distance:
- If the file transmitted to Strava includes the GPS points and the distance between each point, then Strava will take this distance into account
- If the file transmitted to Strava only includes the coordinates of the GPS points but not the distance between each point, then Strava will do the calculation itself
So I think Suunto and Polar files fall under the 2nd technique and Strava does the calculation taking into account the 3D distance. On the other hand, Strava must process the Garmin and Coros files according to the 1st technique.
I'm waiting for Jim Walmsey to upload his track to Strava.
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