Variation in distance recorded on Fitbit

[Stoffel76]

Wanting to get some quick midweek exercise to compliment my weekend rides, I started running...

 

My first run I measured just on the watch (Fitbit Charge 2). According to that I ran 5.7 km.

 

Next time I ran I had my phone with me (Samsung S10e), I ran further but it recorded my distance as 4.8km.  I figured maybe the watch on it's own was inaccurate.

 

Except the next run i did (with both watch and cellphone) was a very similar distance and it recorded my distance as 6.2km. And then yesterday I ran the identical route again and it recorded the distance as 4.6km??

 

I'm not hung up on the actual distance - as long as I'm huffing and puffing and getting some exercise, I'm happy  - but that kind of variation is significant.  What could be causing it?

 

Are there settings on the watch or phone I should be changing?

 

 

[PieterJvR]

As far as I know the fitbit charge or versa does not have a built in GPS (only the ionic does), therefore it calculates distance on stride length or something similar, however your phone has a GPS, so when running with both the fitbit is paired with the phone and therefore uses the phone's GPS (connected GPS).

 

I did a quick google search and it appears multiple people have issues with accuracy when running with their charge 2 on its own

Check these 2 links - 

https://community.fitbit.com/t5/Charge-2/Do-I-Need-to-Bring-My-Phone-With-Me-On-Runs/td-p/3171354

 

https://community.fitbit.com/t5/Charge-2/How-do-I-use-GPS-on-my-Charge-2/td-p/2581845