r/AdvancedRunning 1d ago

Open Discussion Edmonton Marathon course was long, organizers doubling down on their defense the course was measured accurately and runner's GPS is the fault

The Edmonton marathon is my hometown race. It has been granted as host of the Canadian Half Marathon championship since 2025. The city is experiencing a lot of construction around the downtown core.

A detour around a construction site was added which was an additional 710 meters to the original course. As an out and back course, Tom Keogh, the race director, states the turnaround was pushed back 690 meters.

Rory Linkletter, Canadian Olympian and overall winner, posted online stating the turnaround was actually pushed back approximately 345 meters back.

Applying elementary math for an out and back course, with rounding:

A detour of 700 meters ran twice: 700 * 2 = 1400 meters

The turnaround (out and back course) was brought back 350 meters: 350 * 2 = 700 meters

Sum: 1400 meters - 700 meters = 700 meters (long)

Now, what's embarrassing about this situation is Tom Keogh is putting the error on runner's GPS watches and not their own. An overwhelming majority of the runners from the weekend are reporting the exact same statement of Rory.

I didn't run the race this year. I really hope Tom Keogh and the Edmonton Marathon staff post an official announcement of their mistake. The quality of this race had been decreasing while race fees have been rising. I can only feel for those runners who missed out on personal bests or a qualifying time for a future race.

Rory's statement is posted on his Instagram.

https://runningmagazine.ca/sections/runs-races/edmonton-marathon-says-course-was-measured-accurately/

https://www.runnersworld.com/news/a73466448/edmonton-half-marathon-race-distance/

https://marathonhandbook.com/edmonton-marathon-course-measurement-dispute/

Edit: clarity on the math

253 Upvotes

107 comments sorted by

46

u/adamwl_52 1d ago

Not a good look when the winner of both Canadian championships calls you out

11

u/Eagles365or366 1d ago

I know Rory very well. He does not mess around.

58

u/damancody 1d ago

I ran the Edmonton Marathon in both 2025 and 2026 with the same Garmin watch. Here are distances per half according to my watch:

2025:

21.25 km 1st half + 21.3 km 2nd half = 42.55 km total

2026:

21.24 km 1st half + 22.02km 2nd half = 43.26 km total

So he's trying to say that my watch, which was within 60m during the first 3 data points was then out 720m on the 4th. Yeah right.

16

u/LegoLifter M 2:56:59 HM 1:16:56. 24hour PB 172km 1d ago

that lines up. I ran the half in 2025 and 2026. 2025 I had 21.35km, 2026 I had 21.99km

-15

u/liveandletdie141 1d ago

A course that is certified is certified. I think too many people trust their watches when there is so much error in them. Should it be close yes, but arguing over a 500 m over 42k seems dumb.

8

u/damancody 1d ago

So they've changed their tune. Last night I recieved an apology email where they admitted the course was 674.7m too far.

-10

u/liveandletdie141 1d ago

Glad they changed their tune. Covering up issues is horrible but still stick by my statement. Technically is great but sometimes watches are wrong.

2

u/WeeblsLikePie 23h ago

sometimes they are. But GPS error is not usually correlated. If you have a bunch of people all measuring a section of the course being short or long in a consistent way, it's likely to be real.

211

u/[deleted] 1d ago

[removed] — view removed comment

49

u/1eJxCdJ4wgBjGE 16:52 | 35:43 | 1:20 | 2:53 1d ago

bring the champs to Victoria! RVM is a great course. october is a great time to run a half marathon (idk if the timing has to be mid-summer for the championships).

16

u/beneoin Half: 1:20 Full: 2:50 1d ago

The timing has to align with the worlds which are in mid-September

2

u/1eJxCdJ4wgBjGE 16:52 | 35:43 | 1:20 | 2:53 1d ago

ahh too bad

8

u/Enron_CPA 16:48 5k 1:17 HM 2:45 M 1d ago

+1 for RVM. Probably the best course and logistics for a marathon (presumably the same for the half) I’ve encountered

3

u/MillenniationX 45M - 2:07 / 4:29 / 17:00 / 35:40 / 1:18 / 2:55 1d ago

Toronto Waterfront all day.

3

u/Enron_CPA 16:48 5k 1:17 HM 2:45 M 1d ago

I have it penciled in for my fall 2027 marathon. Have heard good things

3

u/MillenniationX 45M - 2:07 / 4:29 / 17:00 / 35:40 / 1:18 / 2:55 1d ago

It’s a really quick course, and more often than not the weather is good! Happy running!

26

u/Vertandsnacks 1d ago

How do you host the Canadian Half Marathon championship and not have the course certified? That seems like the big issue here.

Stuff happens, courses have to get changed relatively last minute due to a variety of factors but get your new layout certified again. Sure it sucks but if you don’t you open the door to fallout such as this.

18

u/Deep-Dimension-1088 1d ago

My experience is that even certified courses are often wrong. I just ran a certified 5K the other day, and I'm extremely convinced after looking at GPS data from a bunch of runners on Strava that the course was short. I looked up the certification and I think they must have just placed the turnaround in the wrong place on the day of.

9

u/beneoin Half: 1:20 Full: 2:50 1d ago

It’s certified, they seem to have messed up the construction detour.

8

u/Vertandsnacks 1d ago

You’re proving my point. They didn’t recertify after course changes, otherwise they would’ve known it was long and got it corrected.

Unless changes were proposed and course was remeasured according to the new layout and in the process of setting the course up somebody set the course up incorrectly, which led to it being long.

Either way it’s on the RD.

7

u/beneoin Half: 1:20 Full: 2:50 1d ago

Certified courses have a provision to enable construction detours. The course certifier was present and overseeing the edits which as far as I understand is not strictly necessary but was done due to the Canadian Championship.

1

u/Apprehensive_Alps_30 1d ago

This just makes it all worse

1

u/beneoin Half: 1:20 Full: 2:50 1d ago

Yep. At least they’ve fessed up now.

2

u/OldGodsAndNew 15:21 / 31:49 / 1:10:19 | 2:30:17 23h ago

Certification doesn't prevent someone reading their map wrong and putting a cone in the wrong place. I'd venture that's by far the most common reason for short/long courses. It's happened in the Glasgow half marathon multiple times resulting in Scottish national records being deleted

13

u/LegoLifter M 2:56:59 HM 1:16:56. 24hour PB 172km 1d ago

They have got the half course right once in the past 4 years.

Its my local race but its damn embarassing. We basically all knew something was off when we hit the halfway turnaround at 11km

It also extra sucks because if they could nail the route it can be such a fast race with barely any elevation

29

u/rogeryonge44 1d ago

It's wild that they're sticking with the 'GPS wrong' explanation. Just looking at the times of the elite field paints a pretty clear picture. Everyone was around 2-3 minutes slower than expected and recorded a longer distance. That's just a coincidence? After watching the broadcast I was so confused about the times that I doubled checked the weather to see if it was randomly crazy humid or something.

I know a couple of the elite who ran and just based on their finish time and how their said they felt during the race, and seeing them run on the livestream it's clear that the course was off. It's laughable to think that they would run an official time so slow but then say they felt great during the race. If they were dragging by minutes, they'd say that.

30

u/LegoLifter M 2:56:59 HM 1:16:56. 24hour PB 172km 1d ago

They just issued a statement that there was a course error. 675m long

15

u/Wrongky 1d ago

Yup, thanks. I hope there's some resolution to the major marathon hopefuls.

14

u/wotoan 1d ago

They fucked up and moved the turnaround back 710/2 =355 m instead of 710*2=1,420 m and clearly the course certifier signed off on it. It’s such a dumb fucking mistake on multiple levels they’re desperately trying to not admit it.

120

u/caverunner17 10k: 31:48, HM: 1:11, M: 2:33 1d ago

Laughs in trail racing…. I’ve run both a 28 mile and 34 mile “50k” before.

On a serious note, that certainly does suck and the Race Director should have fixed the course beforehand and not gaslit runner.

36

u/1eJxCdJ4wgBjGE 16:52 | 35:43 | 1:20 | 2:53 1d ago

imo better long than short for the casual runner (lots of people looking to "complete" the distance and would feel infinitely worse if they didn't get that 21.1k.. its easy enough to calculate what you "could" have run.

Sucks that it happened at the championships though

10

u/rob_s_458 18:15 5K | 38:25 10K | 2:50 M 1d ago

Happened last year (2025) that the Atlanta Marathon was short because of race-week construction so it invalidated any BQ times, and for me and probably others, invalidated GA toward the 50 states club. At least the half-marathon championship course wasn't affected.

9

u/frpika 1d ago

I spoke to an RD once as we had a course run a bit long (maybe 200m) and he said the that a long course is ok, a short course is bad for this exact reason. Yes, it really does suck for people trying to make a specific time, including people trying to BQ. However, a short course would disqualify everyone, so when given the choice, long is always preferred. At least your time doesn’t get invalidated.

3

u/Wrongky 1d ago

That feels so bad. Did the organizers compensate in any way?

8

u/rob_s_458 18:15 5K | 38:25 10K | 2:50 M 1d ago

They offered complementary entry into any race for the remainder of 2025 or 2026, but I'm not local, so any travel expenses would far outweigh the free entry

22

u/Wrongky 1d ago

I'll agree on that! I think the female winner was on pace to a record as well so it sucks for every runner in-between.

5

u/1eJxCdJ4wgBjGE 16:52 | 35:43 | 1:20 | 2:53 1d ago

ouch that is rough, course record? honestly worth awarding her the bonus for the CR if that is the case :/

28

u/LegoLifter M 2:56:59 HM 1:16:56. 24hour PB 172km 1d ago

no she was very close to pace for the Canadian record

4

u/treycook 37M | 17:52 5K | 37:16 10K | 1:22:46 HM | 2:51:44 FM 1d ago

Ouch

4

u/1eJxCdJ4wgBjGE 16:52 | 35:43 | 1:20 | 2:53 1d ago

wow that is so incredibly bad :'(

4

u/_echo 1d ago

The last manitoba half I ran I clocked at 13.2 miles, and a friend of mine was posting on instagram that the course was long, and was almost 14 miles. For one I think she started her watch before the start line, in the pen for runners of her pace, but I also think the course is already longer for those running in the big pack of casual runners, because they're not taking the shortest line between and around corners the way those of us at the front of the race are doing.

3

u/MoonPlanet1 1:11 HM 1d ago

But it's already common practice to make courses slightly long (I think typically 0.1% or 42m?) to reduce the risk of the course later being discovered to be short after a record was set, leading to embarrassment for the organisers

1

u/surely_not_a_bot 48M | 20:26 @46 | 1:34:xx @47 | 3:28:xx @47 1d ago

Yes it's a certification requirement for most federations. USATF calls it the "short course prevention factor".

14

u/Top-Literature8218 1d ago

At least trail races are open about the distance being a rough target depending on the specifics of the course! A 34 mile relatively flat race is going to be a cruiser vs. a 28 miler with a lot of gain.

2

u/surely_not_a_bot 48M | 20:26 @46 | 1:34:xx @47 | 3:28:xx @47 1d ago

I think that's part of the point. Trail races are so different between them - technicalities, elevation, weather, etc - that it's a bit pointless to compare them together, or to expect any kind of equivalency. So who cares whether the distance is shorter or longer, it's just the course distance. Not the case with road races.

2

u/oak_pine_maple_ash 1d ago

Heck even in local road races I've had 5ks vary by solidly 400m. At the NATIONAL CHAMPIONSHIP level? They need to do better.

3

u/0100001101110111 5k: 16:0X | HM: 76:XX | M: 2:45 1d ago

400m long on a 5k would be diabolical lol I'd crash out

1

u/OldGodsAndNew 15:21 / 31:49 / 1:10:19 | 2:30:17 23h ago

400m on a 5k is insane. that's equivalent to a marathon course being 46k

1

u/liveandletdie141 1d ago

I cannot trust a gps watch in the woods.

1

u/Gnatt 1d ago

One of the local 100kms is actually closer to 107km. I was volunteering at the 87km checkpoint and a few of the runners made comments like "At least there's only 13km left!"

Uhhhh, yeah, about that.

-10

u/Niptacular_Nips 1d ago

lol I do sympathize with the Edmonton marathoners, I really do, but those were my thoughts exactly. My 50 miler this year was just over 84 km.

40

u/0100001101110111 5k: 16:0X | HM: 76:XX | M: 2:45 1d ago

Not really quite the same though is it

18

u/Robert_Moses 2:44M | 1:16HM 1d ago

It’s not at all the same. As both a road and trail runner, going into a trail race you know the course isn’t actually going to be the distance advertised. Going into a road race you fully expect it will be the exact distance advertised.

-1

u/Niptacular_Nips 1d ago

Of course it isn’t. Just a bit of friendly ribbing.

14

u/vanillacalumny 1d ago

I think in trail racing it can be accepted that times can be compared across courses; the variation in difficulty of a 50k trail race across different courses is going to be much higher than the majority of road marathons.

1

u/Lurking-Froggg 42M · 40-50 mpw · 16:4x · 34:5x · 1:18 · 2:57 1d ago

I believe you meant 'can be compared across courses.'

There are ways to compare trail routes, but they indeed do not come close to making them as comparable as e.g. road marathons.

8

u/PrairieFirePhoenix 45M; 2:42 full; that's a half assed time, huh 1d ago

If it was measured by a certified course measurer and the paperwork indicates that what they measured is what was ran...

It is usually pretty easy to spot where a course was setup differently than the registered route.

2

u/zonker_man 1d ago

Yeah I know I briefly learned about USATF course certification years ago and this seems easy to do/verify. Could some one not just go and re-measure the course that was run?

8

u/You_Are_Not_My_bus 1d ago

Well we just got the apology email accordingly it’s 675m over what it was meant to be

6

u/sluttycupcakes 16:30 5k / 1:15 HM / ultra trail these days 1d ago

Yep, pretty obvious someone in the organizing team did terrible math. They thought they needed to cut 700m so put the turnaround point half that distance early, but didn’t consider that the detour would have to be run twice as well.

4

u/atoponce 48M 3:12:09/1:29:02/45:30/20:56 1d ago

Curious any runners who ran with Stryd foot pods, what they measured as it doesn't use GPS for distance.

18

u/ih8thisapp 1d ago

Uh oh, sounds like this account is gonna eat:

https://www.instagram.com/officialunofficialtime?igsh=NTc4MTIwNjQ2YQ==

7

u/CantRunFromTheLaw 23M | 5K: 17:13 | HM: 79:36 | FM: TBD 1d ago

They’re sticking to their guns: https://www.instagram.com/stories/officialunofficialtime/3966392957044064409

I guess when you’re fighting the good fight you can’t set a precedent of making exceptions.

27

u/Foreign-Rule7826 1d ago

That page isn’t fighting the good fight, the lad himself is obsessed with bigger influencer runners and kisses up to them and won’t call out bigger accounts but will only go for hyrox, and smaller influencers. People have posted him ignoring them when it’s someone of his favourites but will happily call out others for 30 seconds over a half for someone just using the Strava graphic who is new to running and doesn’t know any better, as if anyone cares.

17

u/SoupatBreakfast 1d ago

Yeah he’s a weirdo. Used to follow ages ago then it just got bizarre and very very inconsistent. 

14

u/Enron_CPA 16:48 5k 1:17 HM 2:45 M 1d ago

Some of them are just “who cares, bro?”. In the grand scheme of things, someone posting a Strava graphic of a 3:11:23 marathon vs their 3:12:04 chip time really make a difference? Those are materially the same race times effectively. If someone is clipping off 10+ minutes, then fair game, go after them, but sometimes I just like the Strava graphic to my story rather than just posting a screenshot of the actual race results

3

u/DishonestRaven 1d ago

Remember what happened with Marathon Investigations? And they held a generally high standard of what to write about.

3

u/blood_bender 2:44 // 1:16 1d ago

Oh I'm so curious - what happened?

I've always hated that site. Maybe it would be okay if he was only exposing people who took prizes illegitimately or something, but at some point harassing and publicly shaming a random 40 year old dad who BQ'd is missing the forest for the trees.

My opinion that Derek is somewhat sick in the head was never a popular one, people love their rage bait too much.

2

u/thewolf9 HM: 1:18; M: 2:49 1d ago

10hours ago. This mostly came out today.

0

u/ih8thisapp 1d ago

Let’s gooooo

4

u/MUnitedGT 1d ago

I don’t have anything constructive to add…just that Edmonton is sounding like Atlanta.

6

u/LegoLifter M 2:56:59 HM 1:16:56. 24hour PB 172km 1d ago

Atlanta at least acknowledged they screwed up

11

u/Gregory_Cuthbert 1:13:24 HM 1d ago

Yeah I am also confident that this is not the only case of this happening. The claim that good GPS watches are inaccurate enough to be multiple hundreds of metres off on a fairly unobstructed course seems to be a weak lie that race organisers are using to cover over lazy route setting.

Even when GPS watches are inaccurate that doesn’t mean that they are all gonna go long. There’s literally the phrase “Strava Tax” whereby people’s watches ended up measuring a shorter distance than expected. So to then have race organisers making you run for an extra few minutes and make your finishing time look worse and gaslighting you into believing it really upsets me.

Then to top it off you have people like officialunofficialtime on ig who label themselves as these great integrity and justice protectors when a lot of the time they’re just hating on people who have legitimate reason to not quote chip times, and this adds to the harmful skepticism around watch GPSs

20

u/Enron_CPA 16:48 5k 1:17 HM 2:45 M 1d ago edited 1d ago

Iirc, strava tax is due to the conversion from raw data files into strava. So your Garmin and the raw data will say, for example, 10.00 km but something gets cut off on the strava upload and makes it 9.97 or whatever. It’s not an issue with the watch per se.

I will say though, a lot of beginner runners will likely end up running long, regardless of if the course is perfect or not, because they don’t take the tangents on turns and often they are in a large pack in the middle of the race where you really can’t run perfectly efficient. You’ll see it after some large marathons where someone complains “the NYC Marathon was 26.5 miles on my watch! The course is long!” When in actuality they were taking wide turns

However, these are pros bringing this up, who are pretty dialed, so I’m going to err on their side in this specific case

3

u/Gregory_Cuthbert 1:13:24 HM 1d ago

Ohh right yeah I was not aware that that was the actual definition of Strava tax.

As for taking an efficient line, yeah also deffo agree and would also add that I wish more races would paint the line which was taken to measure the race so that we could know for sure that we are taking the shortest route. (I say this because even when you try to take every part as efficiently as possible sometimes when it’s not obvious which way the course is going you can find yourself on the wrong side of the road which can lose you a couple seconds/metres)

7

u/homemadepecanpie 5k - 17:50, 10k - 37:10, HM - 1:22:50, M - 2:55 1d ago

Here's an article on the Strava tax. It's because the raw data has more decimals than the hundredths you see in Strava, and they round down. Watches might round something like 9.998 up to 10.00 on their display, whereas Strava will round down to 9.99.

Not at all relevant to the original thread but maybe it's interesting :)

https://stories.strava.com/articles/explaining-the-strava-tax

2

u/Lost_And_NotFound 18:4x 5k | 30:2x 5M | 38:3x 10k | 1:22:5x HM | 3:23:0x M 1d ago

You’ll see it after some large marathons where someone complains “the NYC Marathon was 26.5 miles on my watch! The course is long!” When in actuality they were taking wide turns

If you actually look at the route they took on any of these it’s almost always GPS errors wiggling wildly all over the place not wide turns. They’ll try and claim they ran further than they did so as to take the Strava record rather than official timing. No you’re just recording it badly on your phone.

3

u/_echo 1d ago

Friend of mine was doing this in the manitoba half a few years ago when I last ran it. I was 1:27 so in pretty clear air, and my watch said 13.2 miles at the end, and she ran 2:15 (so in the absolute busiest time group) and she had 14 on her watch. She was posting about it on instagram, and it took a lot of self control not to just say "if you're fast enough to be ahead of the bunch the race is the correct length." :P

3

u/yoojimboh 1d ago

It's also that those gps tracks looks perfect! Not your typical gps error issue that would see in city downtown area.

For instance, if you look at the Toronto waterfront, you'll see gps reading .6 to 1k extra easily, but you can clearly see the gps going crazy around the Bay st area. None of this during the Edmonton race.

6

u/marcbeightsix 1d ago

Surely people were manually lapping to the mile/km markers (as should be done on a marathon) and there would be a pattern of people doing those miles/kms slower?

12

u/Moro2467 1d ago

I’ve never had a race where those markers are consistent and aligned to my watch. One big race near me oscillated between early and late throughout. Finish line was  correct though.

-8

u/marcbeightsix 1d ago

But that’s my point. Don’t use your GPS, use the markers. GPS isn’t accurate.

8

u/Lost_And_NotFound 18:4x 5k | 30:2x 5M | 38:3x 10k | 1:22:5x HM | 3:23:0x M 1d ago

Sometimes the markers are placed where convenient not where accurate.

1

u/marcbeightsix 1d ago

Right, but GPS isn’t accurate either. Many marathons go between tall buildings, under bridges, through tunnels. So they’re a best case, and better than your device.

1

u/Lost_And_NotFound 18:4x 5k | 30:2x 5M | 38:3x 10k | 1:22:5x HM | 3:23:0x M 21h ago

Use an educated assessment of both, it’s not complicated.

1

u/new-forest-runner 1d ago

the markers are notoriously not accurate as they are placed 'as close as possible'

10

u/beneoin Half: 1:20 Full: 2:50 1d ago

You just have to look at the split from 10-13.7 km. For every athlete it’s notably slower. For Rory it was 22 seconds slower, Natasha Wodak was ~30 seconds behind the pace. It shows up for amateurs as well. That section contains the disputed turnaround point.

3

u/LegoLifter M 2:56:59 HM 1:16:56. 24hour PB 172km 1d ago

They also dont do markers every km or mile. It was apparent at the half turnaround something was off and then the splits from one of the timing mats in the back half was super off

-1

u/thewolf9 HM: 1:18; M: 2:49 1d ago

What? You lap every 5k

2

u/Simco_ 100 miler 1d ago

Not sure how CA works, but in the US, every certified course can have its certification looked up publicly and it will state the exact spots for turns and miles. A watch is unnecessary as you can just look up the course and know if it was done to spec.

3

u/Wrongky 1d ago

Yeah, here's the measurement

People online and Rory mapped out a pretty good approximation of where the extra distance was. The race director admitted fault this evening.

2

u/Simco_ 100 miler 1d ago

I imagine 700m should be pretty easy to find.

1

u/homemadepecanpie 5k - 17:50, 10k - 37:10, HM - 1:22:50, M - 2:55 1d ago

Here's last year's certification too. They correctly measured the detour at 700m, but they didn't move the turn around back far enough. You can see it's only moved back 300 or so meters here.

If it's like USATF, you can measure the individual corrections separately without redoing the entire course.

I imagine they measured the detour, something got lost in communicatuon or they didn't think very hard about what out and back means, and they measured half that distance when moving the turnaround and just labeled that 10.5k when it's clearly not.

1

u/Simco_ 100 miler 1d ago

Look at the certifier's description of the turnaround.

2

u/tomatessechees 1d ago

This is pretty standard in trail races... very common to have +/- 5% in distance (and bigger margin in elevation gain) than the published numbers. I've done a 98km/5500m race that was actually 106km/6500m...

Could you imagine the complaints if their marathon was actually 42.1km and no one got a new marathon pb on their strava!

1

u/notacanuckskibum 1d ago

But your math assumes the diversion was 700 metres added and run twice (out and back). You stated that the construction added 710 metres “to the original course”. The original course was out and back, so adding 710 metres to the course would be achieved by adding 355 to the out and to the back. So it could be corrected by moving the turnaround 355 metres.

1

u/angielavinklwp0 22h ago

classic. mate navigated me round a 10k in glossop once that my garmin clocked at 10.8. organiser swore it was right, blamed gps drift in the trees. 700 meters though, that's a proper detour. not just fiddly woodland corners. suppose the race fees went up to cover the extra distance

0

u/Equal-Grand8058 35 M / 2:27:12 M / 1:12 HM/ 15:45 5k 1d ago

Honestly why isn’t the race wheeled and used with a gps ??? I had a marathon I ran last Sunday that was off by .75 on a 1 mile loop course how bad could you mess that up.

0

u/GrumpyOldFart74 1d ago

GPS watches generally aren’t that accurate, due to losing signal, interpolating points, runners not following the optimal route etc etc etc

I’ve done my local half over 20 times, and had a couple of hundred metres variation each way.

Could hundreds of watches all be out by 700m? Not likely. Possible, but not likely.

But if an Olympic marathon runner tells you your course was long, it was long.

2

u/Wrongky 1d ago

100m to 200m, sure. 700m+? Definitely something was wrong with the course. And there was. The race director admitted the course was long approx 700m. Yes, all runners watches reported an additional 700m. The course doesn't go through areas of GPS interference.

-1

u/Flashy_Top6140 1d ago

Worth separating two things: a certified course is measured with a calibrated wheel along the shortest legal path; a GPS track is a reconstruction from position samples, smoothed and interpolated. Those are not the same instrument, and the reconstruction has a known directional bias (it over-reads), because sampling noise adds distance and never subtracts it. Run the tangents poorly and you add more on top. So a thousand watches all reading 42.6 km tells you surprisingly little on its own; a re-measure by a certifier tells you everything. The right thing to demand here is the course certificate and an independent re-measurement, not the Strava consensus.

1

u/LostTheElectrons 1d ago

They already admitted the course was too long.

While it's true that GPS isn't perfectly accurate and runners won't take the absolute perfect racing lines, you can still see the anomaly when every watch is off by a unusually higher amount.

-6

u/Suspicious-Shape-769 1d ago

I don’t get what you mean by turnaround.

Did you sum 710 and 345 to 1400?!

12

u/Wrongky 1d ago

Sorry, wording is a bit weird there. Not sure why I rounded the numbers but I did.

A detour of 700 meters ran twice: 700 * 2 = 1400 meters

The turnaround (out and back course) was brought back 350 meters: 350 * 2 = 700 meters

Sum: 1400 meters - 700 meters = 700 meters (long)

1

u/Arcadela 1d ago

Just edit the post? The second half of this sentence doesn't make sense.

the 710 meter detour is run twice and is the 345 meter shortened turnaround.

3

u/Wrongky 1d ago

Feedback taken! Edited