Let´s run a quarter mile and measure accuracy on the blaze.

[gretchenmoll]

As a fun project I´d like to suggest this

We all run or walk 1/4 mile HS Track Test and video tape the start-and-finish and post a link here to DropBox or a closed youtube channel.

3 Separate  trials should do just fine.

Every post should contain the following.

Height

Stride length

and fitbit blaze reported step count,calories burnt, as well as percentage in Deviancy from actual running or walking length

Wind speed for your area reported on weather.com

altitude and time of day.

Lets give their Engineers a chance to correct accuracy through the power of crowd data collection

thanks

Best regards

[_scottdavey]

It seems the latest September 2016 firmware update didn't fix it 😞

I just ran 5.6 kms and Fitbit thinks it is 6.4 kms. What a joke.

See ya Fitbit, I'm getting another watch.

[shipo]

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@_scottdavey wrote:
It seems the latest September 2016 firmware update didn't fix it 😞

I just ran 5.6 kms and Fitbit thinks it is 6.4 kms. What a joke.

See ya Fitbit, I'm getting another watch.

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Did you run with your Blaze tethered to your phone or did you run with just your Blaze.  If the latter then your stride length isn't set correctly in your profile.

[Theo1967]

In my experience changing the stride length does not seem to make any differences.

On Wednesday I did a 6.26 mile run as measured using GPS and MapMyFitness. As I am trying to set stride length I once again set the Blaze to treadmill so it would use my set stride length. This I had set to 3'6" (low), as an experiment due to previously calculated stride length of 3'9" giving a higher mileage than GPS recorded on a run.

I also ran with a Jawbone Up Move so I had a double check on step count.

The results were Jawbone recorded 9126 steps, Blaze 9164. So happy with step tracking.

As stated above I ran 6.26 miles which should equal a stride length of 3'7" using the Fitbit recorded steps, however the distance recorded on the Blaze was 7.10 miles which calculates to a stride length of 4'1".

I have the latest firmware and the Blaze has been re-started since the update, the inaccuracy is the same as before the update. I cannot understand why my profile changes do not have any affect on the recorded distance. Just a bit frustrating!

[shipo]

@Theo1967, you cannot compare treadmill strides with outdoor running strides; apples to oranges.

Keep in mind a running stride length of any given distance is only a gross approximation and will almost always be incorrect for any given run (see below).  The fact is, if you want to know how far ran during any given workout, you MUST use the GPS/Location Services facility between your Blaze and your smart phone.

Stride length variances:

My most common run distance is about 10 miles; been doing it for quite a few years now.  When I look at the rather large body of data I have from my Fitbit Surge, I see runs where I logged only 1,290 steps per mile (4.1 feet per stride), and as many as 1,760 steps per mile (3.0 feet per stride); that's a pretty significant variance.  If I was to rely on a stride length setting instead of using GPS for my distance, then there is no way I would be able to expect any accuracy at all.

[bbarrera]

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@Theo1967 wrote:
I have the latest firmware and the Blaze has been re-started since the update, the inaccuracy is the same as before the update. I cannot understand why my profile changes do not have any affect on the recorded distance. Just a bit frustrating!

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@Theo1967@ @Changing stride will only change distance estimate on future runs/walks. It will not update distance estimate from past runs/walks. And since your stride likely changes depending on the run (recovery run, interval run, race, etc), its a losing game if you want accuracy.

If you want accuracy on a treadmill, or running without GPS, get a foot pod (search "foot pod" on that website for other reviews). Sending those runs back into Fitbit as activity is possible, using Strava-to-Fitbit or Endomondo-to-Fitbit integration.

[Theo1967]

Thanks for the replies, however I think I have been misunderstood as to what I am trying to achieve.

I recognise that stride length varies considerably from run to run and even during a run.

I always GPS when I run to give me distance accuracy and route tracking.

For the last couple of outdoor runs I have used MapMyFitness with GPS on my phone whilst recording the run as a Treadmill activity on the Blaze to force the Blaze to use stride length rather than connected GPS.

The reason I am doing this is to see if the Blaze is using my set stride length, which it is not. On this 6.26 mile run ( as measured by GPS) the Blaze recorded 7.01 miles which equates to a stride length of 4'1 (9164 steps). The stride length set on my profile is 3'6" which should equal 6.07 miles, this would be close enough to the GPS distance to be acceptable. It would also give me the basis to fine tune my stride length to get the error lower.

Using the treadmill activity my recorded distance should be my set stride length multiplied by the number of steps (regardless of what is happening in reality with my actual stride length or GPS distance), as I said in my earlier post I was happy with the step count being reasonably accurate so the error in recorded distance was due to an incorrect stride length being used. Not one that I have set, and had been set for over 24hrs.

[_scottdavey]

I always run with my phone tethered, with GPS on.

[bbarrera]

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@Theo1967 wrote:
For the last couple of outdoor runs I have used MapMyFitness with GPS on my phone whilst recording the run as a Treadmill activity on the Blaze to force the Blaze to use stride length rather than connected GPS.

The reason I am doing this is to see if the Blaze is using my set stride length, which it is not. On this 6.26 mile run ( as measured by GPS) the Blaze recorded 7.01 miles which equates to a stride length of 4'1 (9164 steps). The stride length set on my profile is 3'6" which should equal 6.07 miles, this would be close enough to the GPS distance to be acceptable. It would also give me the basis to fine tune my stride length to get the error lower.

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@Theo1967 Perhaps Fitbit treadmill mode is compensating for the moving belt by lengthening your stride. Just a guess from what your experience.

Do this - instead of Treadmill mode use Run mode, and be sure to turn off connected GPS before starting the run.

From Fitbit help: "If you see a gear icon in the lower left corner, that exercise offers connected GPS. Tap the gear to see an option for turning GPS on or off. Press the Back button (left) to return to your exercise."

[Theo1967]

@bbarrera I will try this on my next run and let you know