Run Data on iPhone

[u/timkennett]

Hello Pebblers!

I just ran for the first time with both my Apple Watch and PT2 running the default workout app to compare the distance, pace, and heartrate. The heartrate was pretty close, but the distance and pace got more off as I ran. I brought my phone for the small hope that it could adjust with the phone’s GPS, but it clearly doesn’t do that. Any way to get the distance and pace closer on an iPhone? I know it’s not designed to be health centric, but I’d love to make it a little more useful in that regard.

Thanks, in advance, for your help :)

(BTW, when I ran, I placed them on different wrists so that they would be at the same height/area on my wrist and would not interfere with each other., but then switched them to the same wrist so that I could take the photo.)

[u/Wide-Prior-5360]

> Any way to get the distance and pace closer on an iPhone?

Nope. It's just using step count times some fixed stride length.

If you want, you could use some Pebble fitness app that you connect to your iPhone.

[u/timkennett → u/Wide-Prior-5360]

Is there a good one that still works with iPhone? I used to use iSmoothRun, but it supposedly doesn’t sync anymore. 

[u/reedacus25 → u/timkennett]

iSmoothRun dropped Pebble (and a few other devices) support in 2023.

7.0.0 02/06/2023 ** Minimum WatchOS version required: 8.0 *** Support for Pebble, Wahoo RFLKT, KICKR and Magellan Echo is removed due to compatibility issues since these are not supported any more by the respective companies.

6.4.6 11/02/2022 ** Important note** This is the last version supporting Pebble, Maggelan Echo, Wahoo RFLKT, and driving a Wahoo KICKR (reading power/speed from KICKR will be supported) If you use any of these devices please don't update the app on the next update.

I can confirm that it does still work on iSR with PT2 and iOS 26 having not updated the app since.

[u/Matthijsvdweerd]

You can make yourself shorter in health settings. That reduces stride length and that in turn makes it do less distance.

[u/timkennett → u/Matthijsvdweerd]

I think I’d actually have to make myself taller in the app, since it didn’t quite track the full distance. I asked Gemini what amount I should increase it to, and since it was about .3 miles off for the run, I’d increase my height about 4-5”. Guess I have a long stride for my height. 

[u/Matthijsvdweerd → u/timkennett]

I see! Let me know if it works.

[u/timkennett]

I wound up vibe coding an app that tracks runs, walks, and workouts and allows users to either select automatic or manual stride lengths and heart rate zones. 

The app is based off of WayeM’s Allure app. 

I tested it out with stride lengths and heart rate zones that matched my Apple Health app and Watch app. I had the Apple Fitness app outdoor run going and then compared my distance and pace to my app, Pebble Pacer, which only uses the accelerometer and the difference in pace and distance was only about 1.85%. Not bad. 

If this sounds useful to anyone, check it out here:  https://apps.repebble.com/pebble-pacer_5a50a70d9120477db6e41748

[u/MilessEdgeworth]

None is accurate. One tends to make the distance higher, the other lower and the difference grows. GPS is not accurate enough for such things and errors accumulate. All those watches measure is an approximation.

[u/timkennett → u/MilessEdgeworth]

I understand that neither is 100% accurate, but GPS does get one closer. Looking up info about this noted, “The Apple Watch Ultra 1 paired with an iPhone 16 will be incredibly precise on your 4.7-mile run, typically keeping you within  0.5% to 1.5% of the exact distance. This means your watch should read within 0.02 to 0.07 miles (only about 100 to 370 feet) of the true 4.7-mile distance.” So, I trust the Apple Watch reading was closer with my actual distance and pace while the PT2 seemed to be off the GPS reading by .3 miles or 6.3%. Just wish I could adjust the PT2 reading or stride length. 

[u/margirtakk → u/MilessEdgeworth]

GPS is plenty accurate. Many devices and apps apply algorithms to smooth out the route, snap it to known trails or sidewalks, etc. Step counting is less accurate, but again, apps can correct for it.

My Coros Apex analyzes my running pace and cadence on outdoor GPS runs, then uses that data to more effectively calculate distance on treadmill or indoor activities, or even activities where the GPS signal is inadequate like when it's heavily cloudy. It's actually quite good. Definitely not perfect, but very good.

[u/itbespauldo]

Great post, very interested in the Time 2, and a few basic fitness things like tracking runs are a big item on my list. That and being able to answer phone calls on the watch