Fitbit app vs. Strava app

[akreiden]

Hello!

I have a Firbit Charge 2 which I use to track my runs. I recently installed Strava to follow friends' runs so - via connecting my Fitbit to Strava - all my GPS activity is fed into my Strava account. Note that I use Strava passively, I do not push any buttons to start tracking runs there. I use my Charge to start/stop runs.

i just realized that the data that is shown in the Fitbit app is not the same as in the Strava app. Example, my last run:

Fitbit: 8,18km 46:25min

Srava: 8,1km 44:37min

Same for the other runs since installing Strava. How that even possible? Doesn't Strava just grab the data from the Fitbit app?

[akreiden]

Anyone? Please?

[Rich_Laue]

Hello @akreiden, ive moved your third party question about Strava to the correct forum. 

This transfer from Fitbit to Strava happens between their servers and not between the app. Why it is happening i don't know because ive  not used Strava. 

My first thought would be to search this forum for strava and distance.

[Parkersspace]

I'm not sure but I have used Strava for many years for cycling and I also use MMR. One of the things I know make my strava different and more accurate on bike rides is that strava has an auto pause function that works extremely well. If you pause for anything then strava knows and works all your times out based on moving time for speeds/pace etc. So if you stopped to gulp down some water it will show a different time. I also have found the strava app far more accurate at measuring distance than my fitbit app when I do walk. I have run both simultaneously on a trail I know the distance so this could be part of the issue. Fitbit doesn't seem to have as many check points so when I'm hiking the curvy bike trail with switch backs it will be out quite a bit but when on a straight route it's much closer. I no longer use the fitbit gps portion and just rely on strava and mmr for my distances. This means I don't get the distance in my auto tracked work outs on fitbit though but I have found that the fitbit works out my calorie burn based on it's auto track and heart rate (mine is the fitbit alta) very very close to strava's algorithims. Much closer than other apps I've tried.

[ameil]

This exact issue disturb me at first.
But the data actually are the same, nothing is being edited by server or AI.

Please bare with me i try to explain it with my poor English.

Fitbit data show's a RAW data result, what it means is if john run 5.12K in 30 mins it will shows exactly 5.12K in 30 mins in your dashboard. Please set asside gps accuracy, that would be different topic.

Now lets go with Strava, when fitbit does syc your/our data to strava the server do a bit of computation.
First possible noticeable changes is that it will show the 5.12K as single decimal number which in this case 5.1K, however the data still 5.12K it just that it show only the first decimal.

Second and most controversial changes you will notice is that there will be discrepancy in time/duration of your activity. From my example John run 5.12K in 30 mins, strava might show john just run the whole (5.12K/5.1K when rounded) in just 27 minutes.
YES, from 30 - 27 minutes. John will look a lot faster in this case.

So what causes the discrepancy? you might ask.
The strava server analyze your/our data and neglected/subtracted some data that strava server thought we are having rest. For example in the middle of the run we stop for a drink, or we did 2 mins recovery walk. More often These are being deducted/subtracted in the duration of the run.

It also try to correct the bad GPS tracking if there are.

For some athlete this makes sense, and for some this was so confusing but if you still want to see your real/exact duration of the run in strava, it is still there.
In app you cant see it at the moment, you will just notice your moving time. But if you access your strava on web browser there are "moving time" and "elapsed time".

Moving time =  time computed by server

elapsed time = the whole duration of your activity including rest, walk, fueling time, gps missed function

For me having the ability to see both moving time and elapsed time is an advantage.
For long easy run, elapsed time is more important.
For steady state run and tempo run or intelval i rely on moving time neglecting few secs everytime i refuel or stop for a quick comfort room.

Hope this helps

[inUD1]

It seems like you simply do not hit the record button on Strava and Fitbit at the same time, that may be the 2-minute difference. The difference in Km is only a few steps. I started my Strava and Fitbit while standing still and even the steps were identical. Note: The your Fitbit had a longer time and longer distance, you must have started that first.

Trying a test on a track and run for 2 miles, starting both from a standstill. see how accurate it is

[Rich_Laue]

You only want to hit the record button on Fitbit OR Strava, not both of you have linked the two accounts.