How – and How Well – the Coros Track Run(ning) Mode Works

Funny thing(s) about running on a 400m track:

You wouldn’t really need GPS for counting your laps (and thus distance) – but it’s such a clear shape, such open views to sky, people love to record it with GPS watches… and have to find that it’s tough on GPS.

You may know the feeling. You go running on a track, you stay in a lane and know the distances are always the same – and the GPS sports watch you use keeps beeping distance-based laps at you at different points.

Even and especially if you set autolaps to the 400 m of lane 1, it becomes noticeable that GPS watches cannot really measure such a track and the distance on it accurately.

Coros wanted to stand out from that, help to make training on the 400 m running track easier. They just released a dedicated “Trackrun” mode for their Apex, Vertix, and Apex Pro (and shortly coming to the Pace).

Is it ever nifty!

Starting a Track Run

A mode dedicated to running on a track may have you wonder if you need to start (or switch to) it only once you are on the track.

No, you don’t.

You can start in “Track Run” mode for your warm-up run to the track, and it will be measured the same as any other run.

Once you have actually started circling around the track, the watch recognizes that and informs you with a beep (if set up for activity alerts, I guess) and a pop-up screen that tells you that a track was recognized and you should just keep running on it.

First Experiences

It was a bit funny when I went for a whirl with the new Track Run mode.

I started out with a little detour away from the track and then onto it. The first lap around the track, the Coros Vertix I used for this test had issues with the GPS reception; it showed me a bit further out on the track than I was in the southern loop of it, and seems to have lost reception for a few meters in the northern loop.

That first lap also seems to have been recorded as a bit less than 400 m.

Then, coming back on the straight part after the first lap was done, the track recognition kicked in – and I thought I was imagining things.

Coros Track Run Mode Recordings and Autolap Marking

I then ran for 3x 5 laps on the track, in lane 1, once it had been recognized. With (manually set) pauses in between to record what was happening with the watches I was using and to switch around some of them.

Always, a few meters/steps from where the track running had been recognized (for the first set) or re-started after the pause (on the other two sets), the Vertix beeped the 400 m lap marking at me.

Coros Track Run Mode Test
Coros Track Run Mode Test: These are actually 16 laps on that track, all in lane 1

Or at least, word to the wise, it did so once I had actually thought to set it up for 400 m autolaps…

I did not try that out, but it would even have been possible to switch into another lane and switch the watch to that lane (and its respective, slightly different, length), as well.

Coros Track Run Mode Lane Selection
Coros Track Run Mode Lane Selection

Track Run Mode Results

As you can see from the GPS tracks recorded, all but the first (not-yet-recognized) laps around the track are exactly as and where they should be. They were also all recorded as (pretty much exactly) 400 m and certainly marked in the app like that.

Now, I did make things a little easier(maybe) for the Coros by always wearing it on my left wrist, in the same position.

Comparison Recordings: Track Running with Suunto 9 Baro, Polar Vantage V, Garmin Forerunner 945

For seeing how the Track Run mode works, we should also see how track running recordings don’t work quite as well.

Okay, that’s a mean way of putting it; I did want to have comparisons, though.

For those purposes, I also used my Suunto 9 Baro (for the whole time and left on the right wrist), Polar Vantage V (also used the whole time, switched from right to left to right wrist), and Garmin Forerunner 945 (added for the last two sets of 5 laps each, once worn on my right, then on my left wrist/arm).

As usual, I tried to keep the watches at least a few centimeters apart to avoid having them interfere with each other.

And all watches were set up to use GPS+GLONASS. (I would ordinarily have used only GPS, but then the Vantage V would have been the one odd-one-out device since it only does combined GPS navigation systems.)

Suunto 9 Baro in Track Running (Running Mode)

The Suunto 9 Baro I compared the Coros with was always on my right wrist, thus should have measured a bit more distance (since it was always on the outside of the running track).

It did, and it shows the GPS tracks a bit outside from where they were and with a tendency to skew outwards, as well.

The new “wobble-free” GPS firmware in it (2.9, introduced with its last firmware update) still seems to work pretty well for that.

Suunto 9 Baro on 400 m Track
Suunto 9 Baro on 400 m Track (also for 16 laps in total)

The tracks are not as nicely on the 400 m track as the Coros ones, but they are quite tight and consistent.

Polar Vantage V Performance, Recording a 400 m Track Run

The Polar Vantage V, which I switched between right and left wrists, clearly shows the influence of this switch.

Worn inside, the tracks skew inside – to the point where I am shown as having run off the running track.

Worn on the right, outside, wrist, the tracks skew outwards.

All in all, this is a very typical GPS track recording from a GPS watch: It is possible to recognize that it was on a track (especially with the satellite image used as background, duh). It is not accurate, though.

Polar Vantage V on 400 m Running Track
Polar Vantage V, 16 Laps around 400 m Track

It is all the more interesting – if interesting is meant to say odd – how the track recordings went:

The first 5 laps recorded a distance of 2.11 km in total, with the watch worn on the right, outside arm.

Vantage V Laps on Running Track
First 5 (in red) 400 m Track Laps (Vantage V on right arm)

The second 5 laps (with the watch worn on the left, inside arm) recorded a more appropriate 2.01 km but a pretty skewed track.

Vantage V Laps on Running Track
Second 5 (in red) 400 m Track Laps (Vantage V on left arm)

The last 5 laps (with the watch on the outside arm again) measured 2.14 km of total distance, but resulted in tracks that (again) looked rather better in how they follow the course of the running track.

Vantage V Laps on Running Track
Last 5 (in red) 400 m Track Laps (Vantage V on right arm again)

Garmin Forerunner 945 in Track Running

The Garmin Forerunner 945, also switched between wrists (this time, started on the right, then switched to the left; worn only on the later 2x 5 laps), is interesting to see, as well.

The tracks are recorded closer to the running track 1 which I was always using. Thus, position accuracy looks to have been rather better than on the Polar Vantage V and (perhaps) Suunto 9 Baro.

400 m Track Running with Garmin FR945
2x 5 laps on the 400 m track with the Garmin Forerunner 945

The range of where the tracks are shown is still considerably wider than it was from the Coros’ Track Run mode; the influence of which arm the watch was worn on is noticeable but not as strong (let alone skewed) as it was on the Polar Vantage V.

400 m Lap Alerts, the Usual

The Garmin Forerunner 945, having used it with 400 m autolaps, showed the typical problem of GPS watches on running tracks: Every lap, it counted the 400 m as finished sooner and sooner.

In the end, the autolap alert marked the finish of a lap when I had run just over half of the loop…

(At least I used autolaps / autolap alerts here. Aside from the Coros, the Garmin was the watch most easily changed to 400 m autolaps and lap alerts, so I changed that on this watch… and needed a while to find both and turn both off on my next trail run.)

Looking at the tracks and lap markings as they are shown in Garmin Connect is quite instructive:

For one, Connect does not allow as much of a zoom and as thin a line for the track as I used in Google Earth; this hides some of the inaccuracies/spreads in the tracks.

If you are a cynic, you could say that this is hiding things. But, since those inaccuracies are well within the usual errors of the GPS system – and of GPS watches, in particular – the supposed exactness with which I looked at the tracks in Google Earth is a bit of a lie.

400 m Track Running as Shown in Garmin Connect (with Lap Markings)
The 400 m Track Running as Shown in Garmin Connect (with Lap Markings)

Secondly, rather more interestingly, the automatic lap markings make the influence of watch position (at least, when not using a Coros with “Track Run” mode) quite obvious:

The first 5 laps, recorded while wearing the Forerunner 945 on the outside arm (right wrist) show a much greater divergence.

Thus, the watch recorded the 400 m earlier and earlier, because it counted the distance longer (because it was pointing to the outside of the track, thus “thought” that I was farther outside – running farther – than I was).

Worn on the inside, left, wrist for the other set of 5 laps, the 400 m autolap markings are much closer together (even if the tracks recorded do not look that much different, actually, from the ones recorded before…).


All in all… well, all in all this was just one quick test, which is hardly conclusive.

But, from this experience, I’d say that serious 400 m track running is most easily and exactly done with a simple stopwatch and manual marking of laps – unless you have a Coros, set the track run mode up well (not least, with the correct track/lane  you are running in and autolaps for its length), and use that mode.

The Coros team has done well here, it seems – even if I still care rather more about the navigation arrows that this update has also brought! 😉

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