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Analysis of Apple Watch running data

317 points| maarten3 | 3 years ago |applewatchrunner.substack.com

166 comments

order
[+] PragmaticPulp|3 years ago|reply
> After about a kilometer I have to cross a busy street, I need to pause there regularly. Pausing always fixes erratic mode.

Given that the “erratic mode” only impacts the beginning of the run and disappears suddenly at known locations, this sounds like an issue of delayed GPS lock.

And given that the problem didn’t exist in the past, it could be a software issue due to upgrades. Or it could be a hardware issue that developed over time, such as something impacting GPS receive sensitivity. Or it could even be a new source of RF interference in the GPS range near the author’s start point, which impacts GPS lock until they get far enough away from it.

Interesting issue, but note that this issue appears to be specific to this one specific person, not a general issue with all Apple Watches as some in this thread are speculating. I certainly have not noticed this behavior on my Watch even with the latest updates.

[+] kodisha|3 years ago|reply
Semi related iWatch Rant - if you think running data is bad, try tracking your sleep.

It just doesn't work.

- Sleep for 3h - wake up for 1, sleep for 5 more: records 3h only.

- (being a parent of a small baby) do not sleep at all during the night, sleep 4+3 hours during the day: 0 hours recorded

- sleep trough the night but wake up every 90-100 minutes (baby again): 0 hours recorded

Damn, this is a $500+ device, and it cant even get basic sleep data correctly. Also, it takes anywhere from 1min to couple of hours for data to appear in the Health app.

OTOH my wife has ~3 year old Huawei Fit watch, which was about $120, and that thing records every 10-15min or longer nap. Without a mistake.

[+] icebergonfire|3 years ago|reply
As someone who went through the same process, including using a Huawei watch previously, I encourage you to try Autosleep. It has much better sleep detection magic and exposes a few knobs that enable you to fine-tune the autodetection and also manually correct the sleep records in sensible ways.

It integrates with Health, so it has the bonus of tidying up the sleep data all across the board.

Not related to the developer in any way, just a very happy user.

[+] zx10rse|3 years ago|reply
For anyone interested in heart rate accuracy and sleep tracking accuracy I will recommend to check The Quantified Scientist reviews.

From his latest reviews of the new apple watches, heart rate is pretty much on par with chest strap and sleep tracking is also far better than anything he tested.

Apple Watch : Scientific Sleep Test - https://www.youtube.com/watch?v=LPqtfC70QTU

[+] jupp0r|3 years ago|reply
Regarding sleep: the most important reason why these devices suck for tracking sleep is that you have to recharge them every 24h. That's either not being able to use them during the day for some period or do overnight charging.
[+] Tagbert|3 years ago|reply
You probably want to checkout Sleep++ or Autosleep for sleep tracking. The third-party apps go beyond the basic, built-in feature.
[+] mmh0000|3 years ago|reply
As the other poster suggested, AutoSleep is amazing.

I've found if my watch is too loose it won't record sleep well.

It's also a known problem that Apple watches "backup" bugs (which I've experienced twice now). If the problem still continues, I'd recommend you fully unpair/reset your watch and setup it up as a new watch (do not restore from backup).

[+] Oras|3 years ago|reply
I used Garmin Fenix 5 for sleep tracking and it has similar issues. In fact, if I sleep during the day, it doesn’t recognise it as a sleep! I checked the garmin support forums and some other users reported the same thing but garmin didn’t care to fix.
[+] feross|3 years ago|reply
Ditch the built-in sleep tracking and use Autosleep.
[+] m1gu3l|3 years ago|reply
Sleep tracking always seemed like nonsense to me. You either know you are getting restful sleep or know you are not, and if you are not time is probably better spent taking a proactive approach to establishing healthier lifestyle habits that will lead to more restful sleep. How much is it worth really, to wake up and know exactly how much time you were tossing around not getting rest? I’d imagine you would feel it, statistics or not.
[+] cianmm|3 years ago|reply
I’m part of a running group with a mix of Garmin and Apple Watches and the Apple Watches always have pretty different distant readings according to Strava, maybe 2%-5%. The Garmin devices are generally much closer together.

I wonder if the dual-band GPS on the Apple Watch Ultra is an attempt to fix these problems? I would guess that it’s software, with the author, if for no other reason than I’d be surprised if Garmin were all that much better at putting GPS in a tiny housing than Apple.

[+] mtts|3 years ago|reply
> I’d be surprised if Garmin were all that much better at putting GPS in a tiny housing than Apple.

Given Garmin’s long, long history as a manufacturer of (often very small) GPS devices, I personally wouldn’t be.

(I also know for a fact they do mapping better. This summer I was in the South of Italy and only Garmin accurately distinguished between small public roads and long private driveways while both Google and Apple royally messed this up.)

[+] PragmaticPulp|3 years ago|reply
> I wonder if the dual-band GPS on the Apple Watch Ultra is an attempt to fix these problems?

The author said their watch worked fine in the past. It also works fine after a warm up period, which suggests it’s not getting a GPS lock at the start of the workout.

It’s a new issue of either a software regression, hardware degradation, or RF interference near their start point.

[+] sjkelly|3 years ago|reply
Dual band GPS on my Garmin is certainly amazing. It is mind blowing seeing accuracy down to which side of the street I was on during a run.
[+] oezi|3 years ago|reply
I wonder if author really got a GPS fix before starting to run. I have clocked 100 runs on watch os 8 exactely along one identical path and usually it is within 3-5 meters where I get the 1km announcement.
[+] kadoban|3 years ago|reply
> I would guess that it’s software, with the author, if for no other reason than I’d be surprised if Garmin were all that much better at putting GPS in a tiny housing than Apple.

After "you're holding it wrong", anything seems possible. But yeah that does seem more likely to be software, it's a surprisingly difficult and fuzzily-defined problem.

[+] scott_w|3 years ago|reply
This sounds like my experience of the Apple Watch Series 3—absolute garbage for exercise. I think the problem is the GPS hasn’t locked on when you start the run but there’s no way to know this in the UI. The only solution I’ve found is to “start” early, immediately pause, then wait a bit for GPS to locate you before unpausing.

Most sports watches solve this problem by explicitly telling you your GPS status when you are getting ready to track your exercise.

[+] r00fus|3 years ago|reply
Honestly, Apple Watch series 4 was the real "1.0". So many flaws and shortcomings went away when I upgraded years ago from my series0.

Like the M1 Air, that version was a huge upgrade from the previous one you could consider almost an LTS release.

[+] jalla|3 years ago|reply
The watch needs updated GPS ephemeris data to accurately calculate the position, received by an aGPS (Assisted GPS) server (over IP) or by satellite. This takes at least 30 seconds by satellite.

Solution: Tether with IPhone before leaving until fix is achieved, otherwise keep watch outside or near a window for 10-15 minutes before running so that it can update its almanac from overhead satellites and get a fix.

There is no software solution. Buy a newer watch with cellular connectivity and aGPS-support.

[+] ciex|3 years ago|reply
Do you have an explanation for this being a new issue?
[+] xani_|3 years ago|reply
Why it would need such common updates tho ?

And why it couldn't load that data for say month ahead ?

[+] xt00|3 years ago|reply
I wonder if at some point Apple reduced the sampling frequency of the gps position to save power? Since this sounds pretty important to the guy, I would buy a Garmin watch or similar to compare to and run with both. I also suspect one of the challenges here is that taking a lot of corners like in an urban environment might result in rounded paths — like if you ran around a rectangular city block it ends up being logged as a square with rounded corners. Whereas if the sampling frequency was higher it would capture those corners much better, or if the authors runs were more of a straight line.
[+] loufe|3 years ago|reply
It would explain his shortened distances, as low sampling would round out corners, "shortening" the total distance.
[+] marban|3 years ago|reply
I've clocked thousands of ~20km runs across all Watch generations and have never seen a significant discrepancy when measured against something like Google Maps. Urban area without skyscrapers or the like.
[+] matsemann|3 years ago|reply
Related: DC Rainmaker just released his walk through of the new ultra https://www.dcrainmaker.com/2022/09/apple-watch-ultra-in-dep...

Dc is the gold standard in fitness guides. My interpretation is that if you (like me) want a sports watch, buy a sports watch and not a smart watch with sports features. At least too many deal breakers for me. But they're getting better.

[+] hnburnsy|3 years ago|reply
Second this, his Apple Watch Ultra review is amazingly detailed (like all his reviews), opinionated, and he does his best to participate in the comments.
[+] lifeinthevoid|3 years ago|reply
aside: My girlfriend tracks her runs with Strava through her Iphone 12 mini. Upon zooming in, the "straight" parts never look straight and look a lot more like a triangle wave. She consistently tracks around 10% larger distance than my Garmin watch. I've checked on the map, and the Garmin distance is the accurate one of the 2.
[+] MuffinFlavored|3 years ago|reply
What % inaccurate is the Apple Watch and what % inaccurate is the Garmin compared to what the map says?
[+] jerlam|3 years ago|reply
This would also depend on how she's carrying the iPhone. While putting the GPS receiver on your wrist isn't optimal, putting the iPhone in a pocket or somewhere closer and lower on the body where it sees even less of the sky is worse.
[+] cogogo|3 years ago|reply
I have never seen and cannot find the pace graph the author shows as a screenshot from the fitness app. Would love that data. Just spent 10 min googling and gave up. Reminds me of this thread from yesterday https://news.ycombinator.com/item?id=32965288
[+] nmlt|3 years ago|reply
In iOS 16 it’s tap on the workout, then anywhere under Workout details and scroll a bit. That is really no discoverability issue, because there is even a show more button next to it, that has the same function.

But maybe it changed on iOS 16?

[+] 12ian34|3 years ago|reply
I'm delighted with my Fitbit Charge 5. Costs a fraction of the Apple Watch, don't need to buy into the Apple Ecosystem to make it useful. Tracks my sleep and fitness shockingly well. The official app is surprisingly good, and there's an API that works pretty well and has endpoints for most if not all the data.

That said, I'm a casual exerciser, not a proper hardcore sportsperson. For those I'd say avoid a lifestyle device like the Apple watch or Fitbit watches - it feels like Garmin supports that niche better.

[+] tr33house|3 years ago|reply
Just got this too and I love it so far
[+] mwidell|3 years ago|reply
Only way to get accurate real time data when running is to use a good foot pod like Stryd. GPS just isn't as accurate as people think, no matter if you use Apple Watch or Garmin.
[+] rajman187|3 years ago|reply
That's right, GPS error can be on the order of 10s of meters, worse in urban environments. Google (and presumably Apple) use WPS to enhance location data, meaning a triangulation (simplification here) or location based on known WiFi router and bluetooth beacon positions. They also have a team dedicated to more complex geometric calculations of how the GPS signal may be reflected given the known positions of buildings.

But if you have a clear line of sight that's a different issue. I went cycling on a path next to a river and the GPS trace was buttery smooth.

[+] jupp0r|3 years ago|reply
I used the Strava App to track my runs on my Apple Watch 2. At some point it started crashing and I tried out the built in app. It's really not for me, the data is somewhat locked in, graphs are non zoomable, etc. Most notably I couldn't send friends a url to the run.

I ended up switching to a Garmin Fenix 7 recently and I'm genuinely happy with it so far. Battery lasts more than 2 weeks and it does 90% of what I was using my Apple Watch for.

[+] tluyben2|3 years ago|reply
Since the watchOS 9 update, I am the most unhealthy person ever. I saw on Reddit people have the same results but it really went mental; I walked into the local clinic for a vo2max as the watch keeps warning me; it (the watch) was 15 points off on the negative side, and so was my blood oxygen; 10% off on the wrong side. It’s pretty scary for a software update…
[+] odysseus|3 years ago|reply
As a counterpoint, I saw something similar happen after upgrading to watchOS 8 for 7 months, but then I somehow got my vo2max to go back up by losing 5 pounds in 1 month and eating healthier.
[+] aanire|3 years ago|reply
I'm using new SE, prior to that was using Forerunner 245. I went for a run with watch on each wrists, both almost identical GPS wise, 10k run on Apple watch came as 9.99km on Garmin, heart rate almost same, more calories on Apple watch though
[+] balderdash|3 years ago|reply
A friend has both a whoop and an Apple Watch. One or both of them are wrong. He almost never get consistent results between the two, Apple is almost always higher than whoop (avg. heart rate for a given period) it’s a bit depressing.
[+] michaelje|3 years ago|reply
I’ve just completed a 6 month self comparison of the Whoop v4 and Watch S6 for cycling. I found for long endurance efforts they were surprisingly accurate to each other - but during intervals of intense exertion (eg a KOM/hill climb) often the Whoop would read my HR as ~40-60BPM lower while the watch would reflect an expected reading (160-180bpm). Sometimes after 1-2 mins the whoop would “catch up” but it would leave a giant drop in HR graphing for that interval.

This also lowered the avg HR for the workout on the whoop, as you noted. Happy to share an example comparison graph if you’re interested, just reach out.

For what it’s worth, I ended up cancelling the Whoop this month after trying twice to engage with their data team.

[+] s3p|3 years ago|reply
On the flip side, Apple has FDA clearance to use their device for single-lead ECGs, so I would trust their heart rate reading over a hacky tech startup's.
[+] zorlack|3 years ago|reply
OP should run their route backwards for a week. To see if the effect is symmetrical.
[+] zsolt224|3 years ago|reply
When I was running a half marathon with my Apple Watch 6 ( without a phone) I was getting a 1km notifications within 5-15 meters of the km signs. I was super impressed with the accuracy
[+] samastur|3 years ago|reply
According to my Apple Watch I must be the slowest swimmer in the world. I've just spent 3 weeks on the Adriatic coast, swimming an hour twice a day and I lost count of times my watch reported swimming distance of less than 100m (with an absolute low of 4m).

Luckily for me I use it mainly to see how long I've been swimming and don't care about other data because it is obviously useless.

[+] xani_|3 years ago|reply
Reminds me how Sports Tracker (and really most apps) got wonky every time my phone battery got below 15% and got into aggressive power savings (and no amount of convincing would convince Android to fuck off).

Kinda smells like something similar, some aggressive power savings cutting on GPS accuracy or how much app is allowed to run in background.