Something to remember is that this is his pace _after_ pit stops, so his actual running pace was faster. Also notable is that this course was kind of terrible, with four 90 degree turns and three 180 degree turns each lap for 209 laps. There's little doubt that he could run > 200 miles on a course with fewer turns.
I downloaded .gpx of the run and it's 6.7MB.
He started with 4min/km pace, held it for 130km(9 hours) and then He "slowed down" almost linearly to 5min/km when he finished.
Strava also shares the latitude/elevation during the run. (Screenshot in case you dont have Strava https://imgur.com/PuuKo5r) What I find interesting and don't really understand is why the elevation keeps going down during the run, even though he stayed on the same track. Anyone have an idea why that could be?
The elevation in this case is just a proxy for storing the barometric pressure, which is because the actual air pressure is the important thing to track if you are trying to normalize against athletic performance. If the watch logged the GPS altitude, it would be a lot more accurate, but less useful as the air density would only be estimated..
All GPS watches already calculate their altitude (GPS uses three dimensional trilateration for computing the position, so you must get the elevation because you must calculate the three dimensional position). The elevation measure is usually pretty inaccurate in Central Europe. Since the satellites are comparably low above the horizon, flat movements of the runner have a large effect on the run time of the signals coming from the satellites, while vertical movements do not really change the run time and are therefore much more affected by any error.
This is why most portals like Strava run a data correction by overriding the elevation data of the GPS track by tracing the path over their internal elevation model.
The barometric elevation calculation is usually much more accurate and is constantly calibrated on the watch. This breaks down a little if you run for over 24 hours and the weather changes a lot. The drift over the 24 hours of this run amounts to about 8m over 2 hours, which doesn't really matter. And while air pressure can be used to normalize performance of the athletes, the absolute values measured by the barometer are usually pretty inaccurate, while the relative changes are quite accurate. Therefore, they can be used to measure climb/descent, but not really for an absolute air density measurement.
Source: I have worked on a GPS wearable (without barometric pressure sensor).
I didn’t know you could get a watch with more than 24 hours of battery life including GPS tracking (COROS APEX Pro). The accuracy is a bit weird though, the elevation chart doesn’t make sense.
I don't think it's that big of a deal for good running watches. I ran the JFK50 with a three year old Garmin 935 with a heart strap (HRM-Tri) in a little under 11 hours. My watch was close to 50%. That was with GPS updates every second. It would have been much better if I left it at the default, not the ultratrac or whatever they call the endurance battery mode.
It's really only been the last few years that running watches could last >24 hours with GPS tracking enabled.
I also have a Forerunner 935 which I've used for 24 hours, but I think I had it in ultra-mode where it takes GPS samples less often.
Before that I had a Forerunner 230 and I had to charge that mid race during a 100-miler, which was fun to do while running (used an external battery, put the watch and battery in a running vest while running one of my laps).
The latest watches which do 36 hours or more with full GPS accuracy are really amazing.
Apparently the reasoning is that what actually matters is oxygen partial pressure in the atmosphere, not true elevation. Measuring air pressure and reporting as elevation is a decent proxy for what athletes actually care about.
High-end Garmin watches as well. The fenix 7 can do 48+h including tracking, the Enduro2 will likely go 3 days.
And yes, elevation is bonkers, because GPS elevation via watch is about as precise as you guessing. (+/- 400 feet on Garmins, but I'm not sure there are any watches significantly better than that. )
I ran for 8:30 with my ancient Forerunner 235 and it still had some batteries left. Modern watches can easily do 24 hours, even the mid range Forerunner 255 can do 30 hours and the larger 955 can do 42 hours.
That's 36 hours of normal use, with a 60 minute workout[1]. My Fenix 6 lasts 8 days of normal use and currently tells me it can record a 14 hour run even with only 42% battery.
My Apple Watch with Cellular enabled is the only electronic doo-dad that I carry on my bike rides, even up to 100 miles. At the end of the night when it goes on the charger, I might have 20% left. That's good enough for me considering I seldom, if ever, leave the house with a phone.
And if one could ever get a cellular enabled watch without an iPhone, I'll be first in line.
Something to remember is that this is his pace _after_ pit stops, so his actual running pace was faster. Also notable is that this course was kind of terrible, with four 90 degree turns and three 180 degree turns each lap for 209 laps. There's little doubt that he could run > 200 miles on a course with fewer turns.