Total distance and GPX distance are different

I have been using a footpod so I didn't noticed this before, but in my last two runs I was not using the footpod and noticed a strange thing.

The GPX distance is different from the watch indicated distance. In fact, the GPX distance was 5.2 Km and the watch distance was 5.0 Km, the correct distance (measured in a map) was 5.2 Km. This was with 1s log.
I was expecting an error between the true distance and the GPX distance but not between the watch and the GPX.

Did anybody noticed this problem?

0 Former Member over 7 years ago

It's normal to be different, but generally the distance should very close and even more accurate when all is working properly. The watch distance is calculated based on GPS but additionally can be aided by foot pod, watch accelerometer and gyro in bad reception situations, or ultratrac mode.

On one run I remember having severe zig zagging in my GPS track and the distance calculated from GPX file was 4% longer, yet the watch narrowed this to 1% which made the run data still usable.

I'd give it another go and see if it settles for the next run. Might be that since you've been using foot pod the watch internal acceleromater was not calibrated properly. Or just some other temporary glitch.

0 jose.cboliveira over 7 years ago

Today I did the first seaside running (the weather is getting better) and no problem in distance and, of course, no problem in GPS. In fact, the accuracy was spot on and the biggest lateral error was around 5m. This was with 1s and normal GPS and it was raining.
So it seems that all the problems were due to low GPS accuracy that I have in city running.