Garmin Fenix 5S underecording runs by 7-10% but not cycles

Hi, My Garmin Fenix 5s plus regularly under records the distance of my runs by 7-10%. However it records my bike rides spot on. I was wondering if anyone has had similar issues? Garmin support has not been useful.

I have tried all the common troubleshooting for this kind of issue, I have experimented with all the different GPS modes and data record modes. I originally thought the issue may have been with my particular watch, but I am having exactly the same issue with the replacement device. The GPX file that the watch produces, produces a path that looks fairly accurate, this only adds to the mystery.

Has anyone got any ideas??

0 subra over 3 years ago

I assume at cycling you wear the watch, so that its watch face points to the sky. At running you wear the watch, so that its watch face points laterally. And this may be the reason, especially if there is only a weak GPS signal because of urban canyons or dense trees.

I've tested this many times at running activity. If I normally wear the watch at the wrist, the distance is 4% shorter than if I wear the watch 90° rotated on the wrist, so that the the watch face points to the sky. In addition the course is much better and without any drunk man symptom. Furthermore, the end distance for several different runs coincides very well within +-0,2%.

Of course, wearing the watch in this position isn't optimal, because during the run the watch permanently slides on the wrist to the normal lateral position and this is irritating. Also you can't use OHR. I assume, this is flaw in the construction of the watch and the GPS antenna is located in the bezel at the 12 o'clock position.

So I recommend give it a try and look what happens.

0 rdeletoile over 3 years ago in reply to subra

Perhaps it is due to your auto pause setting. I am not a runner but when I ride, the auto pause sometimes tricks the watch into thinking that I am not moving and stops recording.

0 subra over 3 years ago in reply to rdeletoile

For testing the GPS signal reception I've made several continously runs of 10k at the same route and auto pause was always switched off. There is no gap in the pace chart, cadence chart, etc. and there is no GPS drift.