Measuring distance with stride length

[Warface]

Okay. So here is the deal.

I understood that Fitbit measures the length of a run by multiplying steps taken with your running stride length. And that the running stride length, if not put in manually is decided by a preset value based upon gender and length.

I did not put in a value of my stride length and this is my last 2 runs according to my blaze:

run 1: 10540m and 11133steps = stride length of 0,9467 m/step

run 2: 10600m and 10489steps = stride length of 1,01 m/step

This does not give the same stride length for the two runs. Why? it should the be same value for both runs, given that stride length is the same preset value (stated by Fitbit). I really don't understand this.

The reason I am asking is because the run is in reality10000m so the stride length is obviously wrong and I need to adjust it. But since the stride length used by the app seems to be changing I don't know what the preset is.. And this is abviously also a problem. (given that the distance is 10000m it gives me a realistic stride length of 0,90cm and 0,95cm which seems reasonable given that I ran the second run much faster)

Can someone shed some light on this? 🙂 Why is not the stride length the same for the two runs when Fitbit has made clear that they use a fixed preset value?

Moderator edit: format

[Pinks1]

I keep getting different values every day just living with it now and not trust the distance covered unless it's connected to the gps for me it's the only thing that lets it down until they can sort out the issue!

[AngelaMa]

Hello @Warface and @Pinks1 hope you are having a wonderful day! 🙂 @Warface by default stride length is determined using your height and gender to improve the accuracy I would recommend to measure your stride length and running stride length as suggested here. If after updating your stride length you still notice discrepancy please let me know so I can further investigate. @Pinks1 did you measure your stride length? 

If you haven't please follow the instructions suggested above. 

Thanks for stopping by! 🙂 

[Pinks1]

I have measured it but there just seems be no consistency maybe I'm doing something wrong but if you take my last few days every day is different I have set it to 82cm which is too high but tried fidgeting it to get it close to km I walk when I set it to 71 was way to low but having it set to 82 least bit closer I know if I do a run will be a bit higher that's why put run next to it but surly when not running calculations should be the same correct me please if I'm making a mistake some where apart from that I think the watch is great and only take it off to charge it up and shower!
7.35km 10233 steps 71.8cm
10.68km 14341 steps 74.4cm with run
7.42km 10363 steps 71.6cm
10.88km 14519 steps 74.9cm with run
7.75km 10233 steps 75cm
11.58km 14652 steps 79cm with run
9.47km 12873 steps 73cm
19.59km 24350 steps 80cm

[Rich_Laue]

You probably are not doing anything wrong, @Pinks1.

Your stride will be affected by how you feel today, the speed your moving, the terrain, is something else on your mind, or maybe a pain in some muscle?

A slower run will have a shorter stride and need more steps.

What I did was figure my stride over 5 days then took an average. This should be good until I start getting in shape, then I'll need to adjust the stride.

[Pinks1]

I understand strides could be different if run/walk slower or faster but I hardly use gps so if Fitbit use pre determined stride legths should it not be the same all the time my walking stride is set to 82 and run set to 110 so when I hit 10000 steps should have walked 8.2km seeing around 7.4km which to me is not going by the value I put in!

[trevorms]

I have similar problems.  I set my stride length but the results still show that the wrong stride length is used...

For a walk I did, Fitbit reported the following:

Distance: 8.4km

Steps: 8767 steps

Calculated Stride Length = 96cm/step

Stride Length Set in Fitbit Settings=75.8cm and GPS calibration=OFF

For this walk I measured the following using Google Maps:

Distance: 6.78km

Steps (from Fitbit): 8767 steps

Calculated Stride Length = 77cm/step

My actual stride length (77cm) was much closer to the set stride length of 75.8cm.

Please can you tell me why my Fitbit Blaze, the Fitbit App or the Fitbit website is using a different stride length (96cm) to the set stride length of 75.8cm?

I'm really concerned about the accuracy of my Fitbit Blaze for cycling and now walking...what is going on here.

I bought this product in the faith that it was more or less accurate.  However I'm seeing terrible accuracy problems.  If it was within 1cm or so of my set stride length, I would not have a problem.  But to be using a stride length of 20.2cm greater than my set stride length is obviously a big problem.

[AndrewFitbit]

@trevorms Hey! Here's some info about stride length.

"If you track one or more runs using connected GPS, we evaluate that data to automatically update your running stride length."

I'm guessing that's what's happening in your case. I've said this in another post, but this is something our team is aware of and they're investigating.

[bcalvanese]

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@Pinks1 wrote:
I understand strides could be different if run/walk slower or faster but I hardly use gps so if Fitbit use pre determined stride legths should it not be the same all the time my walking stride is set to 82 and run set to 110 so when I hit 10000 steps should have walked 8.2km seeing around 7.4km which to me is not going by the value I put in!

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You also have to take into account if every step is being counted by walking or running and counting the steps, and see if the blaze is counting them all. If all steps are not counting then that could be at least part of the inconsisancy you are seeing.

Not everything is consistant in exercise. Arm could swing a certain way causing some not to count all the time, stride could change because of different factors. I think the main thing is to keep tweaking it until it is as accurate as you can get it for most activities.