GPS inaccurate part 2

[AmandaOrlando]

I'm so disappointed in the Blaze's GPS functionality, and I can't get any straight answers from customer service. The latest is that I was told to adjust my stride length but why should this matter when I'm using GPS?? Typical situation: went on a run this morning that I know to be 5 miles. Garmin watch spot on, Fitbit nearly a mile off. So frustrating!!

[The_Lion]

Your Blaze was connected to your phone all the time? I ask because some people think that the Blaze has GPS, but you need your phone with the Fitbit app running in background. I had no problems with GPS. A run about 5,8km (my sports app told me that distance) is nearly that distance with the Blaze and now my Garmin. Maybe 100m difference.

[AmandaOrlando]

Thanks for your response! Yes, definitely connected to phone. Full bars. I am getting the map of where I ran, but distance way off. Thanks again. 

[The_Lion]

I think that it is not a problem of your Blaze, but your phone. Because the Blaze uses the phone's GPS. If that is not so accurate (Android phone?) there will be differences. You can try another running app and compare. That app and Fitbit can be running together. I did that with Sportractive.

Another question: How do you know that the Blaze / phone is to blame? Do you have the possibility to see the map from Garmin? Maybe it has lost GPS during your run or wasn't so accurate so that some bends are missing. What about the Fitbit map? Running like you were drunk, through buildings etc.?

For answering your question about the stride length: I have no value set for running. It is calculated by GPS information and step count. It seems to fit. My Garmin has no value too and calculated nearly the same length. I set a value only for walking. It is between the length indoor and outdoor. During Nordic Walking my stride length is much higher, that can't be used for all other cases.

[Rich_Laue]

Generally with connected GPS problems, the answer can ve found on the phones end. WIthout knowing what phone is being used makes ut very hard to give anything but generic answers.

[AmandaOrlando]

Thanks for the additional thoughts! Good idea to try another running app to test my phone. I have an iPhone 7, by the way.

I am fairly certain my run is actually 5 miles as I've tested it before. I'm sure that I don't always run completely straight (like a drunk - ha!) but it's just WAY too far off. Nearly 20% off in most cases. I should also add that Blaze majorly underestimates when I walk. 

I do not set my stride length for running or walking. Blaze does it automatically. My best theory is that Blaze is periodically losing the GPS signal and it's filling in with stride length which overestimates distance for running and underestimates for walking. Both again about 20% off.

Also I should tell mention that this inaccuracy has gotten progressively worse. When I first got Blaze it seemed pretty much spot on. The last 2 weeks have been really bad. 

Thanks again for your help. Much appreciated. 

[The_Lion]

Yes, if the phone has poor GPS technology the Blaze only gets that. But there is also the possibilitiy that the Garmin is way off. I read about GPS problems with that model, sometimes the tracks are much shorter than they are.

[The_Lion]

How do the maps of your runs look? Rather straight or suddenly running through buildings, rivers etc.? That makes the distance longer.

[AmandaOrlando]

Thanks Rich! I have an iPhone 7.

[The_Lion]

In the past the iPhone's GPS wasn't so bad. So it can be possible that the Garmin is way off. I just read about GPS problems with that model.

[AmandaOrlando]

Blaze map looks normal. No strange routes. This is an older Garmin model so no maps. There could always be the possibility that the Garmin is off but it's been very aligned with past races that I have done (+1% at most) vs. Blaze said 27.84 for the Disney Marathon a few weeks ago +6%.  Now seems more like +20%! I will try a third app or device tomorrow.