Blaze Inaccurate Distance (Even W/GPS)

[BLMBG]

I have no problem linking my blaze to my phone's GPS.  It tracks distance and route.  But it is dreadfully inaccurate.  What is the point of a device that "uses" the phone GPS when it doesn't pay attention to the distance the more capable device is registering.  Regardless of stride length settings (which should have zero impact on distance anyway, using the phone GPS instead), my Blaze always records wildly inaccurate distance compared to my phone and other workout apps.  I read that, after a few uses, the blaze is supposed to adjust based on differences it encounters between it's internal distance estimate and the real distance per the phone/GPS.  But that's not happening, and I've got lots of linked runs with this setup.  Don't need it if it can't track distance somewhere in the ballpark of reality. Help!

[BLMBG]

I wish there were an option to make it read distance accurately. It is advertised to link and record distance from your phone. And it doesn't. 

[Colinm39]

@AclobosThanks for replying to my post.. I have a low HR as well.. RHR is 50 over the last few days and because of my age my cardio kiocks in at 72bpm. I find the calories burned are high because of the HR.

On a day with a planned walk my calories burned are 124 calories/hr and on a domestic day, no planned walk that drops to 99 calories/hr. I'm maintaining weight at that so my inputs and outputs are OK, but slightly overweight.

On my two Blazes I have established that for domestic type activity the distance is under reporting more than 20%. If I I walk at at least exercise pace the distance is accurate.

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@Aclobos wrote:

@Colinm39, thanks for listing  your test for each device. I have the blaze and it took me about 2 months to get my walking stride set. What I had to do was to mark my walking trail every half mile and count my steps for every half mile, to verify my steps and distance. My walking trail is 4 miles. I was very frustrated when I first started. As you know we have different strides though out the day. When I monitor my steps when the blaze is in auto mode my steps are way off. But when I set my blaze in walk mode and I'm on my walk it's about 97%. I have my walking and running stride set manually. Say have you done any test checking your heart rate and calories burned? So far I know that my blaze is set to burn 72+ calories an hour. I don't wear my blaze at night but when I check it in the morning it registers 689 cal's burned. I have a low heart rate, so I guess my stats will always be off. Hopefully technology will get better, I guess the chest strap is still the best way to monitor your heat rate. The Blaze still has a ways to go to get it right, it's just not fun having do all of those adjustments to get your stats. I guess all toys have their problems. Thanks again for your information.

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[Jrh374]

I'm also super disappointed in the GPS being consistently off!

I walk the same 2 mile loop all the time, start the blaze at the same point and end it at the same point, connected to my phone and the distance is ALWAYS DIFFERENT! Sometimes by as much as a quarter mile! This is unacceptable.

I used to run and used a Garmin with built in GPS, so I'm familiar with the mile markers and know this is definitely a 2 mile loop (2.2 or so it's a good 2 miles for running plus a warmup and short cool down) driveway to driveway, the Blaze is consistently under. Also, my C25K app today said 1.93mi (I started it a little late and it stopped short since it was only day 1 workout 1) and my fitbit app says 1.77mi, door to door. 

Oddly, my steps seem pretty accurate if I have x amount to finish in an hour I will get up and count and they are pretty spot on, but apparently when I connect it to my phone it doesn't do distance correctly.

[VikSteps]

I think I figured out this problem as I had the same issue with connected GPS, only really comes to the fore when the distance is cranked up. Basically the distance calculation used by FitBit is incorrect, you can test it by exporting a TCX file and using http://tcxtools.com/tcx/distance/ to recalculate the distance using the SAME data points as recorded by FitBit.

[bbarrera]

@VikSteps even easier - setup Fitbit-to-Strava sync to have connected-GPS runs/walks/rides sent to Strava, and you'll see accurate distance in Strava.

[Colinm39]

@VikStepsThanks for the links for GPS. In the Southern Hemisphere some of us are reporting an East/West (E/W) accelerator error well over 10%, closer to 20% depending on how much East/West is in the route.  North/South (N/S) is OK.  Also in the Charge HR

I have compared.. MobileRun, MapMyRun, 2 x Surges and 2 x Blazes .... Both Blazes have the E/W error.  The others are withing GPS error allowance.. No dropouts here.

When I do the comparisons with the Surge, the walking pace in the E/W direction on the Blaze immediately gives a pace of about 2km/minute faster. When turning the corner and going  back to N/S and it is OK, then returning to an E/W the pace accelerates....... at a walking pace I could never achieve.

We have worked it out as a distance gain of about 30cm/second (12 inches/second) in the E/W.

That is evident in Australia and Chile and scatterings of others all waiting for the "fix"...

[VikSteps]

@bbarrera That didn't work for me, Strava seems to trust the distance coming from FitBit, so overall distance is wrong but your segments are correct! If you had segments for the whole distance I bet the sum of those would be greater than the distance.

Due to a bug in Strava you cannot export the TCX from FitBit, fix the distance and re-import it with a new ID, it will ignore the distance and give you 0.0km, so you end up in a worse position! (segments still correct though)

[VikSteps]

@Colinm39 Interesting, I don't think that can be fixed with software as it sounds like an issue on the hardware rather than a calculation problem especially if your Surge works just fine.

Hopefully you'll get an updated model!

[Colinm39]

@VikSteps You maybe right, but at the phone end with all of my other GPS Apps including Exercise, Tracking (MobileRun), they are accurate within the expected GPS variance.

So if Blaze and other Fitbit Connected GPS devices have this error in East/West direction, and the feed is from the phone it makes me think it's a programming issue.

This link on the Charge 2 gives you an idea of what others are compiling..

[VikSteps]

@Colinm39 I missed the bit about connected GPS, then it is a calculation issue. The way to confirm is to use the same data points and see if you get the correct results.

If you want to get really fancy you can compare the data points from multiple trackers with https://www.dcrainmaker.com/analyzer BUT it's not free.

[Colinm39]

@VikSteps Thanks for the link. It will keep my brain active.. Not just the walking at my age but the active brain.

I'm sure Fitbit will come up with their fix so we wait patiently.

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@VikSteps wrote:

@Colinm39 I missed the bit about connected GPS, then it is a calculation issue. The way to confirm is to use the same data points and see if you get the correct results.

If you want to get really fancy you can compare the data points from multiple trackers with https://www.dcrainmaker.com/analyzer BUT it's not free.

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[bbarrera]

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@VikSteps wrote:

@bbarrera That didn't work for me, Strava seems to trust the distance coming from FitBit, so overall distance is wrong but your segments are correct! If you had segments for the whole distance I bet the sum of those would be greater than the distance.

Due to a bug in Strava you cannot export the TCX from FitBit, fix the distance and re-import it with a new ID, it will ignore the distance and give you 0.0km, so you end up in a worse position! (segments still correct though) 

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@VikSteps I've played a bit with TCX files and importing into Strava, haven't seen that problem. In fact I took a short 5.4 mile bike ride from last night, exported TCX from Garmin Connect, used TcxTools, verified that it changed distances (5.42 miles vs 5.44 miles), and imported into a test Strava account. Worked fine, so I think the issue you are seeing is either with original Fitbit TCX file, or TcxTools file changes, or you manually edited the tcx. 

Regarding others that are seeing differences between Fitbit distance and sync'd-to-Strava distances:

see reefoid first post here: https://community.fitbit.com/t5/Blaze/Start-from-Blaze-Incorrect-distance-start-from-phone-correct-d...

see Whitedials response in this thread: https://community.fitbit.com/t5/Blaze/FitBit-Blaze-Connected-GPS-Cycling-Distance/m-p/1405572/highli...

hope that helps.

[lablady1962]

I was sent a new Blaze and it is the same as the first one.  Did a 7km walk this morning and registered 5957steps and 6.1km on the Blaze and I used the app Pacer to check the steps and I got 8686 steps and 7km with that.  I would like to trust my Blaze as it cost enough and I like the challenge of the steps but I don't like when I get the steps and don't get credit for it. 

[Sebastian1]

I have the same issue, I run with my dad who has Garmin and his distance is more realistic than my blaze, 

[lablady1962]

I tried many different fitbits and still the same. I switched to a Garmon hr plus. It was much better. But I have finally settled on an Apple Watch and I love it. Much more accurate steps plus some other perks that I like.

Sent from my iPhone

[Jrh374]

I feel like for running garmin is definitely superior than fitbit. If I were running/training for a race I would use my garmin for sure. 

[Aclobos]

@Sebastian1, are you using the default settings for your stride length. I had to readjust my stride length for both walking and running. It took awhile to get it set. Something you might try if you are using default mode. 

[lablady1962]

Nope I tried everything. Not sure why it wouldn’t work but the charge x2and Alta and 2 diff blazes would not work. Switched to garmin and fine and now have Apple Watch and fine

Sent from my iPhone