Running Distance Usually Short?

Stearmandriver said:

So why is the Fenix measuring a shorter distance? 

Unless you know the actual distance you might just as well ask Strava why it measures the distance long compared to the F6. 

There are numerous posts discussing GPS distance in comparison to some other measuring device for every GPS enabled watch from every brand. Whether the difference is short or long there will always be differences. What is important is the magnitude of the difference, Within 10% is often classed as acceptable but more often than not the differences are less than 5%.

True statement, but the path tool in Google earth measures almost exactly what Strava records.  And I often see differences approaching 10% on the Fenix.

And, if the reason were random measurement error, wouldn't we expect to see the Fenix measuring a longer distance roughly as often as it measures a shorter distance?  That doesn't seem to happen. 

The only thing I can think is that the Fenix is not actually displaying the raw distance it's measuring per its GPS, but perhaps over-aggressively applying a smoothing algorithm intended to account for the expected deviations? 

I’ve found the 6X to record short especially on trail runs with a lot of turns. It is over a mile short when running 20’ish miles. I’ve compared this when running with others. They had 935’s, Suunto, 235, etc. All of these seem to be consistent and a mile or more longer than my 6X. 

Stearmandriver said:

The only thing I can think is that the Fenix is not actually displaying the raw distance it's measuring per its GPS, but perhaps over-aggressively applying a smoothing algorithm intended to account for the expected deviations? 

That's exactly how it is. The recording and display is the FIT file. The smoothing is too strong. The problem has been discussed many times in the forum.

If you are interested, do the following :

Go to the Connect website, and find one of your activities which has a too short distance. Export this activity as GPX locally on the hard disk of your computer. Then take this GPX file and import it from the hard disk back into the Connect portal. Probably the distance is now approximately correct.

Stearmandriver said:

The only thing I can think is that the Fenix is not actually displaying the raw distance it's measuring per its GPS, but perhaps over-aggressively applying a smoothing algorithm intended to account for the expected deviations? 

Yes, that seems to be the case. If you take Garmin's GPS track and import it in another tool, the resulting distance always increases. Garmin indeed does some sort of smoothing. 

My theory is that on Fenix the algorithm is tuned to be more accurate at slower speeds (e. g. walking or hiking) where otherwise wobbling would be resulting in  an extra distance. But I suspect the same algorithm, when applied to running speeds, results in distance being too short, and the faster running speed is the more discrepancy is.

Another interesting fact is that recently I did a trail run with my daughter wearing Forerunner 55. Hearing her watch beeping every mile I noticed that my Fenix was measuring about 0.97 miles for every her mile. And that was a fairly straightforward trail run with no sharp turns or switchbacks, and we ran at a moderate speed (not very fast). I believe her watch was more accurate. 

The fact is that almoust all other GPS Sport devices display (running) distance more accurate then Fenix 6 and Garmin musst know about this and do exactly NOTHING.  And it is not relevant of the device messure the distance wrong or they apply and useless smoothing algorithm. Garmin Developers do add more and more calculated vaules with nice graphics but if the source for calculation this values is WRONG they are all useless.

Do you really want an device for 800EUR (F6X) where you have to export and import GPX file to get acurate distace for running? 

Garmin, could you please finally make a statement for this problem?

iGO said:

The fact is that almoust all other GPS Sport devices display (running) distance more accurate then Fenix 6 and Garmin musst know about this and do exactly NOTHING

You may notice that all other Garmin devices are in Sport and Fitness category, but Fenix is in Outdoor Recreation category. I think Garmin sees Fenix as targeted at a different category of users - the ones who primarily use it for walking and hiking. I suspect algorithms on Fenix are intentionally tuned to behave that way. Ideally the GPS smoothing algorithms should be optimized per sport, but I suspect that isn't the case. 

Could be ... but then I would expect to become an notice from garmin ... Your watch is not good for running, if you use it that way, you have to expect not reliable distance and all other metrics too that rely on distance. 

Or much simpler solution .... disable this useless smoothing algorithm for running activity. It is just software solution. 

But for that garmin has to have another developer team, or better to say another leader of a developer team, or boss of the leader ;-)

Welcome to the club. This has been discussed in the forum for a whlle now. It's proofen, Garmin knows it but no update ever provided a fix for this. Use the distance correction in Strava, the manually set the distance in the run in GC. This is what I do. Or use a Forerunner. Because during the run, pace isn't correct as well. I've also noticed: The more the GPS signal is interferred by trees, the less accurate the data.