Why is the Charge 2 so grossly in-acurate compared to the phone it is (supposedly) synced to?

[pgtr]

I'm not talking about the grossly exaggerated step counter that we know about. I'm talking about the considerably inaccurate mileage. 

For example my Charge 2 is pretty consistent in reporting my 5K races to be about 2.7 to 2.85 miles. The course marshals spec out 3.1 miles. My phone records 3.1 miles. Google maps verifies the route to be, yep, you guessed it, 3.1 miles. 

I thought the CHarge 2 was supposed to get GPS data from the phone - why is it so different?

And of course it displays in real-time a considerably slower pace while running. And 50% of the time the recorded results show both shorter distance and slower pace. (the other 50% of the time no data is recorded due to typical normal sync issues)

The little map display on those occasional runs that are actually synced to the app seem to accurately display the route. 

Strange

[Rich_Laue]

Check your stride @pgtr Fitbit does not use GPS for distance dieting a walk. 

[pgtr]

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@Rich_Laue wrote:

Check your stride  

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Been there done that. Several times in fact using (more) accurate step counters over accurately measured flat 1-mile routes, recording step counts and calculating stride length as well as setting to "Auto". No joy. But IMO one really shouldn't have to go to such extremes to coax the Charge 2 into some semblance of accuracy.

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@Rich_Laue wrote:

@pgtr Fitbit does not use GPS for distance dieting a walk. 

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Interesting. Perhaps you could explain the following two questions?

When it's not in-sync (which is typical) with my smart phone it is merely a glorified timing device + BPM. No route information. Either no distance or a ridiculous wag of a distance as to not make it worth mentioning.

By comparison - On those rare occasions it's actually staying synced with my phone it does in fact display a map in the app with a pink line accurately showing the run route. In fact I can measure that pink line using Google maps and it is pretty accurate as to route AND distance is not a gross wag as above. I'd say on average the distance is off by about 'only' 15% WHEN IN SYNC with the phone.

For further comparison, using the Android built-in Google 'Fit' app for running - it also generates an accurate route map, but it calculates the distance dead-on (as well as pace, splits, etc.). It even records steps. But of course it has no access to BPM.

Question: How does the app generate this map/route withOUT accessing the phones GPS as stated above? Or even know what state I'm running in?

Question: So why does the Fitbit app specifically request access to the phones "location" when installing/configuring the app if the app doesn't use the phones GPS?

[Rich_Laue]

When it's not in-sync (which is typical) with my smart phone it is merely a glorified timing device + BPM. No route information. Either no distance or a ridiculous wag of a distance as to not make it worth mentioning

If the above is so then the following could not be possible. 

Question: How does the app generate this map/route withOUT accessing the phones GPS as stated above? Or even know what state I'm running in?

Without GPS then the app doesn't know where you are at. 

Question: So why does the Fitbit app specifically request access to the phones "location" when installing/configuring the app if the app doesn't use the phones GPS?

You don't say what phone you have but the app asks for location services to track the location of your walks and runs, when requested. 

On Android the operating system requires location services, no request for location, to be enabled to sync. 

By comparison - On those rare occasions it's actually staying synced with my phone it does in fact display a map in the app with a pink line accurately showing the run route. In fact I can measure that pink line using Google maps and it is pretty accurate as to route AND distance is not a gross wag as above. I'd say on average the distance is off by about 'only' 15% WHEN IN SYNC with the phone.

For further comparison, using the Android built-in Google 'Fit' app for running - it also generates an accurate route map, but it calculates the distance dead-on (as well as pace, splits, etc.). It even records steps. But of course it has no access to BPM.

Your confirming exactly what I stated, users through testing have confirmed that GPS is not used for distance during a walk. 

[pgtr]

First you state:

"Fitbit does not use GPS"

Then in response to the accurate map displayed on the fitbit app after a 5k run you state:

"Without GPS then the app doesn't know where you are at."

But you still didn't answer the question... Why is it so inaccurate when it displays an accurate map of the run?

"the app asks for location services to track the location of your walks and runs, when requested."

Whoa!? This seems contradictory... Or are you trying to say that "Location services" is not the same as "GPS"?

"GPS is not used for distance during a walk."

So let me get this straight: Your saying (a) the app does not use GPS in your first post. (b) But then in your second post it does use GPS. (c) But in those instances that it does, Fitbit doesn't use GPS to calculate distance - only map location? Are you serious!?

"You don't say what phone you have"

No I didn't and why would that matter? Have used two different Google branded Android phones - both are dead-on accurate using the native Google Fit app when tracking measured 5K runs whereas the Fitbit app is inaccurate as to distance for the same runs (and all subsequent calculations based on distance as a variable).

[Rich_Laue]

The phone matters because I do not know enough about iOS, but as I pointed out, android requires location services to be enabled for a proper forced sync of your tracker. Fitbit is simply reminding you, the user, that this is requirement of android, not Fitbit. 

Why is it accurate while recording a map? Maybe because users have confirmed Fitbit uses stride, not gps for distance. If the user's properly sets their stride, the distance is very close. Why do I say very close? Because most people's stride will vary a little from day to day. 

You keep saying that the Fitbit app is inaccurate, are you starting the walk recording from your wrist, or through your Fitbit app? Starting from the app does use gps. 

[pgtr]

"Fitbit uses stride, not gps for distance."

That is a truly idiotic design oversight.

"You keep saying that the Fitbit app is inaccurate,"

Because for training and competitive distance runs it is.

"If the user's properly sets their stride, the distance is very close. "

I've used step counters that are more accurate than this fitbit rubbish to gather step data over accurately measured 1 mile flat distances to establish my baseline. Then I using very simplistic mathematics to produce stride data. 

"Why do I say very close? Because most people's stride will vary a little from day to day."

Perhaps I'm unique: My run stride does indeed vary when recovering from injury, when running at extreme altitude vs sea level, when running hills vs flat, when running a tight vs open course, when running a slippery vs dry course or a crowded vs sparse event. Sometimes I'll have a kick at the end of a race and sometimes I won't. 

But this begs the real question: Why ignore the highly accurate information a smart phone practically rubs Fitbits nose in?

"are you starting the walk recording from your wrist, or through your Fitbit app?"

Wrist. Runs only - I gave up bothering to use the (typically unsynced) device for tracking other activities due to recurrent syncing issues.

"Starting from the app does use gps."

Indeed. Which begs another question: 'Why have the wrist device at all?'

It is highly deceiving to see accurate map data and inaccurate distance data munged together in this fashion. In my opinion, it's just a fundamental no-no to mash-up inaccurate data with accurate data the way the Fitbit developers did here. This is made worse by the poor decision or gross oversight to ignore the accurate distance data clearly available to the app. Any serious attempt to use the product as a training tool for running is rubbish.

I very much appreciate your patience. It's been educational for me. I understood the device by itself has limitations. But Fitbit deceived me when I selected the device - I was lead to understand they had indeed leveraged the small, aesthetically designed wrist device with the power and accuracy of the 'synced' phone. Together they could be a serious training tool, at least for running. 

Alas, the underlying product is actually an engineering hack that (when it does actually manage to remain synced) produces rubbish while ignoring the rich data available by the (in theory) synced phone. Quite obviously it's time for me to look past Fitbit branding and cosmetics and look for a brand with a serious solution. They got my $ but I'll be sure and share my Fitbit experience with others in the running community.

Again, thanks,