Workout distance awful!

[Andy in Embsay]

I keep seeing people saying that the watch uses the accelerometer for distance measurement - I'm almost 100% certain that IF the phone is present it uses the GPS for distance - and that's what's odd here. The GPS in my phone when I use the Strava app is pretty much spot on with my Garmin. When I use the Workout app (which I do cos I want the activity logged in Activity app) it's always short.

I've had my AW sinve launch day and have probably run c150 miles with it, always with the phone with me and always with a Garmin on the other wrist - and it's consistently short of what the Garmin says by c0.05 miles per mile - that's not a huge amount but for it to be consistently wrong (and always the same way - short) then this isn't GPS inaccuracy, it's something more fundamental.

 

[Andy in Embsay]

http://www.apple.com/uk/watch/health-and-fitness/ - this says (at the bottom):

"Along with its accelerometer, Apple Watch uses GPS on your iPhone to more accurately measure distance and speed during workouts you do outside — like walking, running and cycling."

 

[iPhysicist]

First you have to run at a consistent pace for a good calibration. That's quite difficult for not so active runners. I run 40km per week and I don't call myself an active runner but I tried my best to stay within strict boundaries to achieve the best result possible.
I did my run on a cycleway along the river Elbe. No high buildings and no traffic lights and only little turns. Unfortunately there are some bridges I crossed. I mapped the run with google maps beforehand and knew the distance between my starting and endpoint. I did this distance 4 times with 3 speeds and hit the measured distance +/- 50m. I also tried to run the exact path every time but that's not possible aus you can imagine.

My first attempt to calibrate the watch was a complete failure as I wrote before. I did the run in my neighborhood with traffic and 4 to 6 level buildings lining the street, crossings an a lot of turns. It doesn't take a psychic to to foresee the result.

Maybe running watches (never used one) have a better gps reception and signal interpretation than the iPhone. That would explain the big differences some see here.

I'd like to ask someone with a well calibrated watch (without phone) and a running watch to do a comparison.

 

[swordfish5736]

Errr I have calibrated it, it's racked up over two hours tethered to the I phone!


Oh and garmin has proven accurate to with about 0.02 of a mile on IAAF measures courses that's a hell of a lot better than Apple watch.

People need to stop defending the watch, until it uses actual GPS and not the accelerometer it will be rubbish for running

But just being connected to your phone while running isn't "calibration"

Here is apples guide to properly calibrating your watch
https://support.apple.com/en-us/HT204516

 

[exxxviii]

But just being connected to your phone while running isn't "calibration"

Here is apples guide to properly calibrating your watch
https://support.apple.com/en-us/HT204516

Logging more than 2 hours of running probably meets all of the criteria in these instructions. Apple does not really tell us to do anything special for calibration other than to run or walk for at least 20 minutes. The only minor hitch is the instruction to run or walk at multiple speeds with the watch & phone if this is normal practice for the runner. However, that is also likely met by 120 minutes of running.

 

[mush10]

I did a run yesterday. Apple Watch (with iPhone in Spibelt pouch) showed 7.94. Garmin 620 showed 8.07. To me that is too big of a discrepancy to use for training. I am going to continue to use both since I usually bring the iPhone along for music and to have a phone if I go in a long run.

As I said in another thread, for 90% of people this is a great solution. If you are running, training, working on pacing, etc. it is probably not the perfect solution just yet.

 

[Julien]

Just finished a 6 miler and I'll list a few of my last runs and accuracy. Distance in miles.

Garmin 620 w/HRM - Watch - iPhone 5S running Nike+

6/22 G620 6.15/AW 5.88/Nike+ 6.21
6/20 G620 8.06/AW 8.02/Nike+ 8.52 (stopped at LA Fitness and it somehow added about ½ mile)
6/18 G620 5.26/AW 5.05/Nike+ 5.47
6/15 G620 6.36/AW 6.32/Nike+ 6.48
6/13 G620 10.02/AW 9.68/Nike+ 10.0

 

[exxxviii]

My hunch is that the Workout app is as good as it is likely to get. In its current state, it is not useful for a runner managing performance. You cannot get map, elevation, or cadence data or see the run's splits. The only driving reason to use the app today is that it is the only way to get a workout into the Activity app. However, I bet that apps like Nike+, Runkeeper, Strava, MapMyRun, etc. will have native integration in the near future that will let them push accurate run data directly into Activity. When that happens, people will simply quit using Workout.

I only have three runs so far, so not a lot of data or calibration time. My reference is a Garmin 910XT.

6/22 G910 5.06 miles vs. AW 5.00 miles (exact same course as the 6/19 run)
6/20 G910 8.28 miles vs. AW 8.01 miles vs. 8.27 on RunKeeper
6/19 G910 5.04 miles vs. AW 5.14 miles

 

[Julien]

Just for kicks here is my first 4 Watch runs:

4/25 G620 12.02/AW 11.62/Nike+ 12.1
4/27 G620 6.06/AW 5.74/Nike+ (didn't use)
4/30 G620 6.20/AW 6.23/Nike+ 6.48
5/02 G520 10.09/AW 9.68/Nike+ 10.6

 

[r0k]

I use runkeeper on my iPhone with my AW merely acting as a display. There was one spot where I doubted runkeeper when it showed a slightly shorter distance for a (supposedly) USATF certified 5k course. Then I realized the cops were turning runners back at the wrong intersection. I'm pretty sure they were supposed to be set up about 1/10 a mile further north so everybody had great times that day and runkeeper on my iPhone wasn't so far off after all.

As for a watch with GPS, I don't care so much. My friend has a Garmin wristwatch and it fails to get a signal on many of our runs while runkeeper on my iPhone works every time.

 

[swordfish5736]

Logging more than 2 hours of running probably meets all of the criteria in these instructions. Apple does not really tell us to do anything special for calibration other than to run or walk for at least 20 minutes. The only minor hitch is the instruction to run or walk at multiple speeds with the watch & phone if this is normal practice for the runner. However, that is also likely met by 120 minutes of running.

it could meet the criteria but it could just as easily not meet the criteria. It specifically asks to run/walk in an open flat area at a consistent pace. So it sounds like running in a hilly area could alter the calibration, or even somewhere where you are slowing down/stopping at intersections for traffic could have an effect.

 

[exxxviii]

it could meet the criteria but it could just as easily not meet the criteria. It specifically asks to run/walk in an open flat area at a consistent pace. So it sounds like running in a hilly area could alter the calibration, or even somewhere where you are slowing down/stopping at intersections for traffic could have an effect.

The OP can chime to confirm, but realistically, this met the calibration criteria. He is running with a Garmin 620, which is the top-of-the line running watch, and he knows what an IAAF certified race is. His run that started the thread was 7 miles-- not a trivial distance. Finally, he got the watch last Wednesday, which means he logged 120 minutes of running in 5 days. These are all indicators of a regular runner who is probably running at a steady pace and stride length that is not heavily influenced by terrain. Additionally, his inaccuracies align with the others in this thread.

Apple's instruction to run in an open area is an awkward way of saying that you need to run in an area that has good line of sight to the GPS satellites. And, if you read further in, Apple is instructing users to run at a varied paces to give the calibration a variety of cadences and stride lengths to use for calibration. So, after 120 minutes with an advanced runner, the AW should have more than enough quality data samples to calibrate very well.

 

[firewood]

Simply run with your iPhone. It will auto calibrate every time you have your iPhone with you.

You might also have to run with both the Watch the iPhone over extended periods covering the full range of your normal running speeds and cadences.

People with accuracy issues might either not have finished enough calibration runs BEFORE using the Watch to measure a running distance. Or not have calibrated the Watch while running at a very different speed or cadence then their measured run.

 

[Andy in Embsay]

You might also have to run with both the Watch the iPhone over extended periods covering the full range of your normal running speeds and cadences.

People with accuracy issues might either not have finished enough calibration runs BEFORE using the Watch to measure a running distance. Or not have calibrated the Watch while running at a very different speed or cadence then their measured run.

Am i missing something here? Everything I've read from Apple says that if you have your phone with you the watch will use its GPS to measure distance. Calibration is to allow the watch to measure distance when there's no GPS - either no phone or indoors. Why do people keep banging on about calibration when the AW consistently measures short when it has a GPS signal. The "calibration instructions" linked to above say:

"You can calibrate your Apple Watch to improve the accuracy of your distance and pace measurements during walking or running workouts when GPS isn't available (such as when you walk or run outdoors without your iPhone, or use a treadmill).". The key phrase being "...when GPS isn't available..."

Why all the posts about calibration when I (and everyone else, pretty much, who have a problem with distance measurement) is running with a GPS receiver ie an iPhone?

 

[anez]

I have to agree that I've noticed some inaccuracy lately, especially since I updated to 1.01.

I do the same walk a couple of times a week-- it's literally the same path, so the distances should be more or less identical every time, especially since I rarely do the walk without my phone.

Except they aren't. The difference isn't as huge as what the OP has posted here, but it can be up to 300m in a ~3.5km walk (i.e., reporting 3.3km one day, and 3.6km the next)-- a difference which is closer to 8% than 3%. I deliberately calibrated the Watch when I got it first, though I haven't done anything else to fine-tune its distance tracking beyond taking both Watch and Phone with me every time I go out, and even Apple says:

You don't need to do anything specific to start this calibration process. It can be done during a regular outdoor walking or running workout in the Workout app when you have your iPhone with you.

Then again, perhaps it's just getting more accurate over time? The Apple site also says this:

And, whenever you use Apple Watch and iPhone to walk or run outside in the Workout app, it will continue to calibrate the accelerometer by learning your unique stride length at different speeds, and get more accurate over time.

I'll have to do it a few more times and see.

 

[Julien]

Am i missing something here? Everything I've read from Apple says that if you have your phone with you the watch will use its GPS to measure distance. Calibration is to allow the watch to measure distance when there's no GPS - either no phone or indoors. Why do people keep banging on about calibration when the AW consistently measures short when it has a GPS signal. The "calibration instructions" linked to above say:

"You can calibrate your Apple Watch to improve the accuracy of your distance and pace measurements during walking or running workouts when GPS isn't available (such as when you walk or run outdoors without your iPhone, or use a treadmill).". The key phrase being "...when GPS isn't available..."

Why all the posts about calibration when I (and everyone else, pretty much, who have a problem with distance measurement) is running with a GPS receiver ie an iPhone?

I originally thought this also. However Apple doesn't say the Watch is using GPS point to point mapping data. Here is a good description of how it works by a developer and a link to the post.

https://forums.macrumors.com/threads/apple-watch-gps-issues-during-workouts.1877989/#post-21227759

This is incorrect. Location for all apps and the AW since its tethered to iPhone is provided by CoreLocation, a framework on the phone for gathering location data. No app has direct access to the GPS. When you want location info you make an API call and the phone returns the data. You can have 5 apps open all using GPS and the AW. It doesn't affect accuracy as it's just asking phone to return positional data.

OP, the AW doesn't actually use GPS to determine position. If you select outdoor workouts from the workout app (run walk cycle), it will use GPS data to improve the accelerometer. This improvement is through better calculation on your stride length. While Apple says calibrate through one run/walk logically to me this will take 5 or more data points for most people whose stride is not consistent every run. For professional runners perhaps less.

I would do a few workout runs on various terrains and then see if the AW accuracy improves.

 

[mush10]

I posted a run from this weekend above, but I actually did a calibration run on a prior day. I specifically spent the first twenty minutes on an outdoor track before continuing my run elsewhere.

On that run my Garmin 620 was 5.37 and Apple Watch was 5.21.

I actually have a Fenix 3 on the way that should be even more accurate as it taps into Glonass satellites as well. I will post some comparisons with that as well.

 

[firewood]

How anyone can say the distance difference is "not that bad" is beyond me it's quarter of a mile!!! That's huge!

Whether it's huge or not in terms of percentage error depends on the ratio of that quarter mile to the total distance. Over a marathon, it's less than 1%. 1% to 3% error is not uncommon for non-differential consumer GPS units (ever priced a GPS suitable for professional surveying?!). Try your other GPS watch or handheld unit multiple times over the exact same closed course at different times of day, different temperatures, different paces, different directions on the same course, and you might be surprised to occasionally see a few percent of difference or error as well.

Am i missing something here? Everything I've read from Apple says that if you have your phone with you the watch will use its GPS to measure distance. Calibration is to allow the watch to measure distance when there's no GPS - either no phone or indoors.

The Apple Watch does not have a GPS chip, and the iPhone is not guaranteed to use its GPS receiver to measure distance. The iPhone uses Core Location, which "occasionally" uses the GPS receiver, but not always, to in order to minimize battery usage. Other times, both the Watch and the iPhone use Core Location and Core Motion to estimate distance from nearby cellular tower and WiFi access point triangulation, and from cadence.

So you need to calibrate the Watch so that the latter speed and distance estimate from cadence is accurate enough during the times while the Watch and iPhone are trying to minimize battery use (which is likely more often that you might think, even while running).

 

[Andy in Embsay]

Whether it's huge or not in terms of percentage error depends on the ratio of that quarter mile to the total distance. Over a marathon, it's less than 1%. 1% to 3% error is not uncommon for non-differential consumer GPS units (ever priced a GPS suitable for professional surveying?!). Try your other GPS watch or handheld unit multiple times over the exact same closed course at different times of day, different temperatures, different paces, different directions on the same course, and you might be surprised to occasionally see a few percent of difference or error as well.



The Apple Watch does not have a GPS chip, and the iPhone is not guaranteed to use its GPS receiver to measure distance. The iPhone uses Core Location, which "occasionally" uses the GPS receiver, but not always, to in order to minimize battery usage. Other times, both the Watch and the iPhone use Core Location and Core Motion to estimate distance from nearby cellular tower and WiFi access point triangulation, and from cadence.

So you need to calibrate the Watch so that the latter speed and distance estimate from cadence is accurate enough during the times while the Watch and iPhone are trying to minimize battery use (which is likely more often that you might think, even while running).

Ok, that' helpful (but not what Apple's own stuff leads you to believe) - odd that Strava (on the iPhone and presumably watch) DOES use GPS constantly - and I also struggle to see how AW measures cycling without using GPS more or less constantly as there's no cadence as such. In my experience Strava and cycling are far more accurate than running on AW.

 

[Encoder]

Ok, that' helpful (but not what Apple's own stuff leads you to believe) - odd that Strava (on the iPhone and presumably watch) DOES use GPS constantly - and I also struggle to see how AW measures cycling without using GPS more or less constantly as there's no cadence as such. In my experience Strava and cycling are far more accurate than running on AW.

I'm noticing similar issues. I use the AW app, and Nike+. I'm going to start using Map My Run as well to see how that works. I used to use MMR for iPhone before the AW came out. If I use AW start the apps, does it use my iPhone for GPS? I always take my iPhone on runs.

 

[FSUSem1noles]

Hmmm. This is strange. I've been doing 2 mile walks, jogs/runs around the neighborhood and the watch has been surprisingly accurate as far as distance. At first I was skeptical so to make sure I checked it against google maps distance and my wife's fitbit sure enough all three are within .01 of each other.

Used it yesterday on the treadmill and the distance matched what the treadmill calculation was. The only difference was the heart rate monitoring which was a little higher on the treadmill but I'm not entirely sure the treadmill monitoring is completely accurate as to measure your heart rate you have to grab and hold the 2 bars.

For what it's worth I have taken my phone with me on all the walks, jogs/runs. Even yesterday on the treadmill I didn't put the phone on the holder but left it in my pocket.

P.S- I've only used the built in workout app on the watch. I'm not currently using RunKeeper or Nike+

 

[exxxviii]

If I use AW start the apps, does it use my iPhone for GPS? I always take my iPhone on runs.

It probably depends on the app. I have been using RunKeeper for my long weekend runs on the iPhone before I got my AW. This past weekend, I used the AW RunKeeper app to track instead. It used the phone's full GPS to track and map my run, just as if was started on the phone. From what I have read, I think Nike+ does the same, and probably MMR too.

 

[ninethirty]

Mine's been awful too. I went for a 2 hour ride on both Saturday and Sunday and it barely clocked me in as having gotten 30 minutes of exercise (I was not biking slowly). Plus, it literally took that 2 hour ride, and a 4 miles of walking to get to the 650 calorie mark for the day. Something seems seriously off to me. I can burn 650 in the gym on an elliptical in 50 minutes.

 

[MrMoonUK]

The OP can chime to confirm, but realistically, this met the calibration criteria. He is running with a Garmin 620, which is the top-of-the line running watch, and he knows what an IAAF certified race is. His run that started the thread was 7 miles-- not a trivial distance. Finally, he got the watch last Wednesday, which means he logged 120 minutes of running in 5 days. These are all indicators of a regular runner who is probably running at a steady pace and stride length that is not heavily influenced by terrain. Additionally, his inaccuracies align with the others in this thread.

Apple's instruction to run in an open area is an awkward way of saying that you need to run in an area that has good line of sight to the GPS satellites. And, if you read further in, Apple is instructing users to run at a varied paces to give the calibration a variety of cadences and stride lengths to use for calibration. So, after 120 minutes with an advanced runner, the AW should have more than enough quality data samples to calibrate very well.

Thank you! My point exactly, I am a regular decent level runner and accurate distance matters, my Apple watch is not good enough.

People keep banging on about calibration, it's calibrated according to apples instructions. Apple need the workout app to use GPS as my garmin uses its internal GPS, for now the Apple watch stays in the gym

 

[Newtons Apple]

Thank you! My point exactly, I am a regular decent level runner and accurate distance matters, my Apple watch is not good enough.

People keep banging on about calibration, it's calibrated according to apples instructions. Apple need the workout app to use GPS as my garmin uses its internal GPS, for now the Apple watch stays in the gym

They have excellent running apps for people who are really into running but they are for you phone with GPS and are VERY accurate. The watch is not what I thought it would be in this category. It would be nice if the watch would use the GPS from the iPhone but . . . . .