Running with GPS. Why is the distance so inaccurate?

[plantoschka]

Maybe this was all part of the Apple Health Master Plan <insert diabolical laughter>

By giving us incorrect distances, they hope to make us run/bike/walk/jog farther and farther each day by making every mile longer and longer . . .

Might be

On my last run I made a couple extra meters to get to 10km at the end. Otherwise it was like 9.6 KM (Runtastic 10Km).

 

[SpEe1113]

Today's Test

So I tried a little test today, ran for about 20 mins in my neighborhood on the side of the street and then tracked the EXACT route using the internet version of MapMyRun (not using the iPhone app) where you can drop pins along the way to see how long your route is. The Apple Watch was 0.10mi short of the actual distance. This is my 6th outdoor run using the watch. I'll try the same route for the next 3 runs and will compare the distance again to see if there's any change/improvement. Heart rate and other data seems to be pretty good/accurate or at least par for the course. It would be nice if it allowed you to edit the distance so it would "learn faster" so to say...

 

[Jayne Doe]

My watch has ALWAYS measured somewhere around .10mi short per mile. That is, until yesterday when it was mega off. This morning, it was back to the normal .10 shortage.

I've had mine since the 24th. It's never learned/measured any differently until yesterday. Thankfully, today it forgot whatever it thought was right yesterday. <shrugs>

 

[SpEe1113]

My watch has ALWAYS measured somewhere around .10mi short per mile. That is, until yesterday when it was mega off. This morning, it was back to the normal .10 shortage.

I've had mine since the 24th. It's never learned/measured any differently until yesterday. Thankfully, today it forgot whatever it thought was right yesterday. <shrugs>

I wonder if the "learning" part relies on repeating the same routes/times/etc... I would think not, but perhaps if things remain constant would it "learn faster"??? Haha, who knows... It's just weird that it's a tenth off for multiple people. That's actually a rather big difference when it comes to running...if it was a couple hundredths off that would be more expected...

 

[Jayne Doe]

I wonder if the "learning" part relies on repeating the same routes/times/etc... I would think not, but perhaps if things remain constant would it "learn faster"??? Haha, who knows... It's just weird that it's a tenth off for multiple people. That's actually a rather big difference when it comes to running...if it was a couple hundredths off that would be more expected...

Meh. I take the dog out daily on the same route. Still get the .10 mile differences.

I'm resigned that it will just be this way. Perhaps an update will cure it. But I've taken my watch on walks/runs/rides for six days a week since the 24th. No learning has taken place. However, as long as it is consistently wrong by this .10th of a mile, I can deal with it.

Did I get a dumb smartwatch?

 

[plantoschka]

https://www.apple.com/watch/christy-turlington-burns/

In one of the last pictures you see 26.44 Miles. That's pretty exact. Probably just a rendering. The real watch on Ms. Turlington probably said 24.x Miles ;-)

 

[Jayne Doe]

Latte on keyboard. I bet you're right!

 

[dhy8386]

So I tried a little test today, ran for about 20 mins in my neighborhood on the side of the street and then tracked the EXACT route using the internet version of MapMyRun (not using the iPhone app) where you can drop pins along the way to see how long your route is. The Apple Watch was 0.10mi short of the actual distance. This is my 6th outdoor run using the watch. I'll try the same route for the next 3 runs and will compare the distance again to see if there's any change/improvement. Heart rate and other data seems to be pretty good/accurate or at least par for the course. It would be nice if it allowed you to edit the distance so it would "learn faster" so to say...

Try the same thing with Bluetooth off so it's not using your GPS to calibrate. Just the accelerometer.

 

[SpEe1113]

https://www.apple.com/watch/christy-turlington-burns/

In one of the last pictures you see 26.44 Miles. That's pretty exact. Probably just a rendering. The real watch on Ms. Turlington probably said 24.x Miles ;-)

Haha, good math there! LOL, or maybe hers is the only accurate one on earth right now...

I'm sure this will be addressed in the first Apple update; I can already picture the line: "This release includes improved performance, bug fixes, and accuracy improvements to the workout app."

Wishful thinking???

 

[plantoschka]

I hope Apple knows. Then they will fix that. They should have noted this issue while testing the device. But maybe they tested the workout capabilities only indoors (ABC Video) and never took it out because of fear to loose it or get it stolen.

 

[SpEe1113]

Try the same thing with Bluetooth off so it's not using your GPS to calibrate. Just the accelerometer.

Will do my next run without the phone, same route and we'll see!

It would be great if there were ways to directly report the data from the watch/phone to Apple, as opposed from them just randomly collecting the data from you (if you checked off that option of course). Meaning, you can directly report that the distance is off, how, why, etc. so they can actually use that data in their improvements... I did report my findings to https://www.apple.com/feedback/watch.html

Time will tell...ha...

----------

I hope Apple knows. Then they will fix that. They should have noted this issue while testing the device. But maybe they tested the workout capabilities only indoors (ABC Video) and never took it out because of fear to loose it or get it stolen.

Good point, but you would think they could find an indoor track somewhere that would tell the exact distance to them too, right?

 

[Jayne Doe]

Try the same thing with Bluetooth off so it's not using your GPS to calibrate. Just the accelerometer.

Genius!

I just tried this. Turned off bluetooth on phone. Found corded headphones. Started Workout App on watch and started Runtastic Pro on phone. Results were almost identical over a quick two mile run!

Does this mean bluetooth must always be off or at some point in the future when it has "learned" my stride, I'll be able to turn it back on again?

Thanks so much! (Especially from dog who got in an extra run!)

in the past i've always run with bluetooth headphones. results always at least .10th of a mile off. this was first run ever with watch and corded headphones/bluetooth off.

 

[SpEe1113]

Genius!

I just tried this. Turned off bluetooth on phone. Found corded headphones. Started Workout App on watch and started Runtastic Pro on phone. Results were almost identical over a quick two mile run!

Does this mean bluetooth must always be off or at some point in the future when it has "learned" my stride, I'll be able to turn it back on again?

Thanks so much! (Especially from dog who got in an extra run!)

in the past i've always run with bluetooth headphones. results always at least .10th of a mile off. this was first run ever with watch and corded headphones/bluetooth off.

Very interesting, I'll try the same. Yeah, I usually run with bluetooth headphones too, hate the cord but...LOL, in the name of science?! HAAA, anyway, I'll try the same and will report back. That will be crazy if it's the phone connection that's throwing it off...

 

[dhy8386]

Can't really say definitively but I have done lots of testing and sometimes aw when doing the calibration thing gives results that are a bit off from where they should be vs when it's not able to do that (GPS unavailable). I was under the impression that it's was only using GPS data to refine your stride length after a run/walk but perhaps it's doing it real time which may mess with accuracy a bit since distance measure is always based on accelerometer readings regardless if GPS is being used or not. When I turned it off and did a vanilla route where I knew my movements would be consistent, it was very accurate.

I am pretty sure that you can "disable" the GPS capabilities by going into Location Services/system services and toggling off motion calibration and distance. I think this is what provides the watch with access to the GPS and positional data. Then you can leave BT on. Just keep in mind this does impact accuracy of the m7/m8 chip in iPhone which is doing the exact same thing as watch - calibrating its own accelerometer sensors. But I'm fine with that since I'm not relying on phone for step data.

 

[jday7757]

I haven't gotten my ⌚️ yet but since it sounds like biking is more accurate than running, have any runners tried running with the watch set to biking? If it's true the biking setting samples GPS more frequently then that setting might record more accurate distances while running.

 

[plantoschka]

I haven't gotten my ⌚️ yet but since it sounds like biking is more accurate than running, have any runners tried running with the watch set to biking? If it's true the biking setting samples GPS more frequently then that setting might record more accurate distances while running.

Possible. Did a 40km ride today and watched showed 39.5km. Pretty good

It shouldn't even mess up active calories too bad. Cycling and Running active calories is almost exactly the same (at same workout time). Even at lower heart rates during cycling.

I really don't get Apple's algorithms. Running should be like 1.5x-2.0x more active calories than cycling.

I think the heart rate only plays a minimal aspect in the active calories measured.

 

[SpEe1113]

Try the same thing with Bluetooth off so it's not using your GPS to calibrate. Just the accelerometer.

Ok, I did another run this morning, same route as last time but before turning off Bluetooth I wanted to try one more thing, I set a distance goal to see if this made it more aware of the distance. Interesting findings:

Run 1 (using a time goal): 2.28 mi
Run 2 (using distance goal set to 2.30): 2.32 mi

The actual distance of the route is 2.38mi confirmed via MapMyRun's online pin drop map tracker. So it seems this is heading in the right direction...

I'll do a third run on Monday without my phone to see where that clocks in, will do it with an open goal as well.

Lastly, I also did a walk after my run, typically the same route with my dog, usually it registers as 1.0mi or 1.01 miles. So today I did it without the phone and surprisingly enough it registered right at 1.01.

 

[Alith]

My watch has ALWAYS measured somewhere around .10mi short per mile. That is, until yesterday when it was mega off. This morning, it was back to the normal .10 shortage.

I've had mine since the 24th. It's never learned/measured any differently until yesterday. Thankfully, today it forgot whatever it thought was right yesterday. <shrugs>

This. I had hoped it would calibrate over time as Apple suggest but I've also been running with the Workout app and a phone since the 24th and it's just as inaccurate as it was the day I got it. The instant pace is so ridiculously incorrect I have lost faith in it and the total distance is always short by a random amount. It's not fit for purpose.

 

[SpEe1113]

Try the same thing with Bluetooth off so it's not using your GPS to calibrate. Just the accelerometer.

Ok, so I ran this morning without the phone connected to the watch (airplane mode) and did an "Open Goal" run... My watch was actually less accurate without the phone connected. Here are my findings:

Run 1 (using a time goal): 2.28 mi
Run 2 (using distance goal set to 2.30): 2.32 mi
Run 3 (open goal, not connected to phone): 2.27 mi

Again, the actual distance of this particular route is 2.38 mi confirmed via MapMyRun's online pin drop map tracker.

I'm not quite sure what to make of this...I'll go back to having the phone connected and see if it goes back in the more accurate direction...we'll see...but for now, yeah it seems to be about 0.10 mi off...

Just adding in here that I've recorded well over 10 runs before testing this out as well...you would think that would be enough to "calibrate" the watch a little closer than these findings...

 

[Tylervit]

I ran a half marathon yesterday and used my watch. The half marathon is 13.1 miles and my watch recorded it as 12.86 miles. I think that is pretty accurate, especially because I usually tried to run on the inside parts of the road to make it as short as possible lol

 

[SpEe1113]

I ran a half marathon yesterday and used my watch. The half marathon is 13.1 miles and my watch recorded it as 12.86 miles. I think that is pretty accurate, especially because I usually tried to run on the inside parts of the road to make it as short as possible lol

Well, this just got more interesting! Update 1.0.1 is supposed to address, "Distance and pace during outdoor walk and run workouts"...have you guys installed it yet? I'm doing it now, but won't be going for another run until Thursday morning.

 

[same0717]

Ran a series of tests this evening trying out some of the various different theories and combinations which had been discussed in this tread. For these tests I ran the same know one mile loop in my neighborhood 5 times trying out different combinations each time.

For these tests I used an
iPhone 6 with software version 8.3
Stainless Steel Watch with software version 1.0.1
Headphones both regular wired and bluetooth

The known 1 mile route as mapped from my computer.

#1
Nike Running App on iPhone
Watch Workout - Outdoor Run w/ no goal

iPhone wifi and bluetooth both ON.

Bluetooth headphones connected to iPhone

[#2
Nike Running App on iPhone
Watch Workout - Outdoor Run w/ no goal

iPhone wifi and bluetooth both OFF.

Regular wired headphones connected to iPhone

#3
NO iPhone - powered off and not carried
Watch Workout - Outdoor Run w/ distance goal of 1.0 miles.

Bluetooth headphones connected to Watch

#4
NO iPhone - powered off and not carried
Watch Workout - Outdoor Run w/ no goal

Bluetooth headphones connected to Watch

#5
Nike Running App on iPhone
Watch Workout - Outdoor Run w/ no goal

iPhone wifi ON
iPhone bluetooth OFF

Regular wired headphones connected to iPhone

 

[bluecow]

I've used Run Keeper on my phone and the Watch Activity app for fast paced walks/hikes both at the same time. Over the course of 6-8 miles at a time, they will be only about 1/10th of a mile off so that is a pretty high accuracy rate.

What has seemed odd is that the watch seems to pick up excess distance when just bumming around the house. I am not certain that I didn't walk 2 miles around my small 2 bedroom apt, but the watch seems to think I have.

 

[plantoschka]

@same0717


I hoped Apple Watch OS 1.01 would improve accuracy. Doesn't look like that :-(

 

[dhy8386]

Ran a series of tests this evening trying out some of the various different theories and combinations which had been discussed in this tread. For these tests I ran the same know one mile loop in my neighborhood 5 times trying out different combinations

And you have motion calibration on in location services? I have over 30 runs in parks and streets and have never come close to that level of inaccuracy.