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thedoc46

macrumors member
Original poster
Sep 22, 2015
81
28
Apple Watch 4 / Watch OS 5.2 / Paired to an iPhone XS iOS 12.2

Anyway every morning i get up and do a cycle. Boring ol' me same route every day more or less the same pace. I have a bike computer which is calibrated by the wheel diameter. I basically do the same 10.40 miles every morning. I throw on my airpods, some Spotify, reset my bike computer, start a cycle workout and go at it.

Except, my workout is cheating me and sometimes its a lot. Like today, the speed and distance wasn't showing and at the end of my 10.40 mile cycle, it showed only 7.48miles, which of course reduces the speed by a substantial amount. Pretty much making the workout app useless to me.

Weird thing is i had an original launch day Apple Watch, which started selling me short, but i though ok it doesn't have its own GPS, so i'll let it off, but then when i got my new Apple Watch 4 when they came out, it was working great. Giving me more or less the same as my bike computer. I thought it had finally was not cheating me anymore. But it just seems to be getting worse and worse now.

I really shouldn't care. I'm not exactly getting any faster with age. Its just that where i work, actually collects our data and gives us financial incentives like gift cards and so on, for being active. So its probably costing me $100 here and there.

I've hard reset the watch, always closed down any background apps on the phone and watch, restarted the iPhone even though that shouldn't have anything to do with it given the watch has its own gps.. But its just so hit and miss, more miss recently.

I can't imagine it being a hardware issue. But then again, anything is possible. Am i the only one who has this issue. I know some runners and cyclists take their exercise a lot more seriously than i do, and this must annoy the heck out of them... Unless i am an isolated case ?

Any advice ?
 
Apple use some intelligent distance Computation based on more sensors. I am not sure anybody but Apple knows in details how it works. Workoutdoor app can disable this and use gps distance. But when looking the exercise in activity, Apple may still use their own intelligent distance, since it differs from what workoutdoor says. E.g yesterday I Went for a 9.2km walk (with intelligent distance disabled) according to workoutdoor, but activity says it was 9.82km.
 
Not sure if this applies, you might check:
Settings > Privacy > Location Services > System Services and turned on "Motion Calibration & Distance"

and while you're there in Location Services, ensure Apple Watch Workout is set to While Using
 
Thanks, all the settings are as should be. I've reset the phone and watch. The thing i'm noticing is when i go into activity, and see the completed activity, where it shows you the map on the route you've completed, its scattered with grey dots here and there, instead of being a stead green/yellow/orange line, showing how fast you were going. Basically showing me that the watch is losing its GPS calibration and just making it up. Problem for my particular workout is i'm going up and down the same roads, so if i was just going in a straight line i'd probably be ok, but if it looses the gps while i'm going up the same road, and doesn't re-connect until i'm going down the same road, then it thinks he's gone no-where, and that's where i believe the problem is.

Kinda annoying. Wondering if i should go to the Apple store or just wait and hope for an update that'll fix this.
 
go to the health app, find "cycling distance" (it's in my favorites, can't remember exactly where it is but probably under "health data") and select "show all data", for me it shows 10-12 entries per minute, and it shows the watch on every entry for device it got the data from ... check that data
 
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Apple Watch 4 / Watch OS 5.2 / Paired to an iPhone XS iOS 12.2


I'd update my Watch to 5.2.1 and my phone to 12.3. If the problem persists, I'd take it to an Apple Store and show them the data.

I've personally never had any GPS issues with the Apple Watch. If anything, it overestimates straight-line distance by about 1%.
 
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OK today i decided to do away with the airpods, and wear just regular ear pods.. The problem goes away. So i think the phone is probably struggling to run GPS and all the transmitting it does via the W1 both at the same time. Or at least since one of the updates it has. Never was a problem in the past using Air Pods.. Seeing that i do the same' ol same ol' route every day, i'll have some more definite answers in the next coming days. Like i'll cycle tomorrow without any music to see today wasn't just a day it decided to work.. Today i just wore ear pods and no grey dots on the map ! So i think i'm onto something here.
 
Today i left the phone at home entirely. So just the watch. No streaming off the internet, no music to process, just the watch and it was pinpoint accurate !!!

Matched my cycle computer exactly. So we know the problem. I'm surprised i'm the only person noticing this.
 
Hmm tonight or tomorrow maybe try it again with the airpods and phone and see if you have any luck?
 
That is all very odd. I seldom run with my iPhone, but when I do I see no difference. (I do bike with my phone, and I also see no difference in tracking efficiency.) And when I do run or ride, either with or without my phone, I am listening to music, audiobooks, or podcasts on AirPods. If the Watch by itself can handle music, bluetooth audio, HR tracking, GPS, and workout tracking at the same time, I don't see why an iPhone would have issues.
 
Hey @thedoc46

Can you compare the maps from the two rides that were accurate against the ones that were inaccurate?

Are there spots in the map that are missing? Truly very interesting.

ft
 
Yes, i'll be testing more scenarios. Is it Spotify streaming data that's making the GPS hangup ? Easy to rule out. I'll just run with local music. Is it the extra W1 connection knocking out the GPS ? again, i'll use wired headphones. With everything on, its a different result every time.. It gets anywhere between 80-90% of the cycle. Whereas today, 100% no phone, no airpods. Just the watch and its gps.

I do the same route every day so easy to divide and conquer !
 
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