Unstable GPS Track on Run Profile

1. Forgot to add: I even ran with friends using Venu SQ 2 and Forerunner 55 and surprisingly,  I got a completely different output from them. My tracks looked so unstable.

I am not sure if the 165 has the settings option as the 965 under the activity settings, or if it may make a difference , but just in case:

Select Run Activity , Go to Run activity settings (hold in up button) , If you see 3D speed and 3D pace listed there , make sure to toggle them off.

Also just make sure the sat setting in the activity itself are what you wanted. Sometimes things change unexpectedly.

Have you synced with Garmin Express on Laptop. Maybe someGPS mapping file (or whatever its called ) needs updating.

Failing which I'd contact support they are normally very responsive

My 2 cents:

- change smart recording to 1-second recording. In 2024 there’s no reason to use smart recording imo

- before starting your run, make sure you truly have a good GPS fix. In my experience (with the last 8 years of Garmin watches), when the GPS ring is green, that doesn’t necessarily mean you have a good fix, especially if there’s lot of tall buildings around. The telltale sign of a fake GPS fix is that your pace is changing wildly even if you’re standing still. (If you start your recording at this time, the track near the start of your run will be bad.)

What I always do is wait for the green GPS ring, then I wait for the pace to settle to zero. Sometimes it can take 30 seconds to a couple of minutes for the pace settle after the green ring appears.

S.M.R. said:

If you see 3D speed and 3D pace listed there , make sure to toggle them off.

Newt G said:

you are right, unfortunately, about FR165 not having the setting for 3D speed and pace. That is actually a good suggestion, that might be the workaround to the excessive processing during a run activity. I just hope it’s possible to bring that feature down to 165. 

3d speed and distance are off by default in devices that have them, so it wouldn’t help to bring those features to the 165, only to ensure they’re turned off. In case you’re interested, they’re intended for runs which have high elevation change. Normally Garmin watches only take into account horizontal movement when calculating speed and distance. Those features enable selected devices to also take into account elevation change for speed and distance. While this would be great for mountain runs (for example), it’s clearly not a good idea for normal runs which are mostly flat.

https://support.garmin.com/en-CA/?faq=J1fLrNa12T7hUAdWHyIXk8

S.M.R. said:

Have you synced with Garmin Express on Laptop. Maybe someGPS mapping file (or whatever its called ) needs updating.

If you’re referring to EPO files — which are supposed to help your watch get a GPS fix more quickly — they are also synced via Bluetooth or Wi-Fi (for watches which support it). If you’re syncing regularly, you shouldn’t have to worry about an out-of-date EPO file. The main thing to remember is if you run in a new location, it’s a good idea to sync first to update your EPO (which is location-specific).

https://support.garmin.com/en-IE/?faq=CevbI1mlnV2SejYAaOQZ29

https://support.garmin.com/en-CA/?faq=6IbaJEHc1i9gydzQomXzyA

On my 955, I can check whether it has a current EPO by holding UP for settings, selecting System > About and scrolling until I see a page which says Ephemeris followed by the status (in my case, Ephemeris: Current).

Either way I don’t think lack of current EPO per se will give you a bad GPS track, at worst you will have to wait longer for a fix.

Also, running dynamics don’t have any effect on your GPS track and more data points is better than fewer, in general. You should have a smoother GPS track with 1-second recording versus smart recording, for example.

It would be helpful if you posted screen captures of what you're seeing.

Hello! Thank you for the tips. I did some investigation by exporting the activities in TCX format and looks like I found the root cause. My watch was not using my current setting (Smart data recording) during my Run activities ever since. I looked into the file and compared it to my Walk activity and saw that there are track points every second. Something seems to be broken or not functioning as expected because it seems that my watch is bypassing/overriding the user setting or forcing the Every Second data recording on Run activities. The Walk activities, however, is working as expected. It follows the data recording setting when I switch it to Every Second / Smart. 

I performed a test by manually updating the TCX file and removing the track points to make them 5 seconds apart and got the expected result after reuploading it to Garmin connect and a third party app. 

Here is the screenshot of the GPS track from the original activity:


Then here's the GPS track of the modified TCX:



Here's the original activity on Strava:

Then here's the modified TCX when uploaded to Strava:

I forgot to include that on my initial post  but I posted them on my other reply just today. 

Newt G said:

Something seems to be broken or not functioning as expected because it seems that my watch is bypassing/overriding the user setting or forcing the Every Second data recording on Run activities. The Walk activities, however, is working as expected. It follows the data recording setting when I switch it to Every Second / Smart. 

Setting the recording mode to “smart recording” doesn’t imply that it will only record every few seconds or that it will never record once per second.

It means that the watch will only record data when necessary (i.e. when there’s meaningful data to record).

The simplest explanation here is that when you’re walking, you’re moving slowly enough to only have meaningful data roughly once every few seconds. When you’re running, you’ve moving much faster, therefore data is recorded more frequently.

The “rough” GPS track that you’re seeing in the case of the Run activity is a more accurate representation of the actual GPS data than the smooth track you see for the Walk activity. The only reason the Walk activity has a smooth track is because the actual data points are relatively far apart, so Strava and Garmin Connect will fill in the blanks with connecting lines that look smooth to you.

If you’re wondering why a GPS track with more data would look rough, here’s a few guesses:

- it’s a fairly accurate representation of how you actually ran

- it’s a reflection of the fact that GPS isn’t a perfect technology (it’s not super accurate)

- it’s possibly an indication of environmental interference (e.g. from tall buildings)

Reality is fuzzy. There are no perfect shapes in nature, and we don’t run in perfectly straight lines or follow paths exactly.

Long story short, I don’t think there’s anything wrong here, I think you are assuming that a smooth track means “better data”, but I actually think it means less data (which imo, is worse data).

There are watches which will snap your GPS track to a stored route. Garmin’s track mode will snap your GPS track to a standard 400m track. Sure, maybe those GPS tracks “look better”, but do they reflect how you actually ran? Maybe in the case of track mode, but idk about the case of “snap to route” feature. Both cases attempt to make your GPS artificially nicer, but at least it’s somewhat defensible if you ran on a 400m track. The other case feels like cheating to me.

Again, if you set your activity recording to once per second, you will get more data, which imo is better data. I bet you will see “rough” GPS tracks for both running and walking activities. Sure, if you want an artificially smooth track for running activities, you can always delete 80% of the data….