Suunto 7 Experiences in the Mountains 1: Sonnsteine Trail

My must-go mountain trail, this time with a focus on the Suunto 7…

GPS Track(s)

In terms of locations and tracks, the differences are the usual; they are due at least as much to different algorithms in the watches as they are to the actual recordings of the position.

The above complete view is actually the highest zoom level on Google Maps which still shows topographical lines (using the “Terrain” view option). Any closer-in, and most detail gets lost from the map.

Remaining details do include the roads and the trail taken here – but how exactly this is drawn in, and how exactly I follow it, is questionable.

Not much to see here.

Looking closer, some differences become apparent.

The Polar Vantage V has a tendency to be a bit aside the other watches; it was on my left hand, and that might have played a role in that.

The Suunto 9 and Garmin fenix 6X show pretty similar tracks; the Suunto 9 shows the impact of a GPS algorithm focused on track clarity: the meandering in the tracks is gone. This is usually for the better, but makes this watch draw fewer of the twists and turns.

The Suunto 7, on the other hand, reacts a bit too strongly to any and all turns, exaggerating the track where I did turn, but did not turn quite that far.

Same thing on mountain trail sections. It becomes very noticeable which watches were on my left vs. right wrist/hand/arm (Polar Vantage V left hand, Suunto 7 left wrist, Suunto 9 right hand, Garmin fenix 6X Pro right wrist).

I’d say that the Suunto 9’s new “clarity” is most recognizable; the Suunto 7 otherwise tends to react / record just like the other watches.

Back from trail to road, forest to town, same thing.

Suunto 9 simplifies perhaps a little more than it should, Suunto 7 and Garmin twist a bit more but look good, the Polar Vantage V produces some oddities, I’d say.


Distance on trails, with twists and turns, starts and stops, is not (yet) the strong suit of the Suunto 7, though.

Suunto 77.83 km
Suunto 96.69 km
fenix 6X Pro6.95 km
Polar Vantage V6.53 km

With its sensitive reaction to changes in direction, the Suunto 7 overcounts the distance by a fair bit. Now, which is the most accurate distance, given how twisty such trails are, is hard to tell… but I have a whole history of testing at the Sonnsteine trail, over years, so we can have a look at something a bit more statistical.

The look at distances recorded over time shows very nicely how all the recordings drift apart, but the Suunto 7 more than the other watches I used here:


Given the very different distance recording(s) – and not to forget, this is an activity somewhere between hiking and running, in the mountains, on twisty trails (at least, for the middle part of it) – pace values should vary.

And they do, very much so.

In comparison, over all, they differ from each other and from the average (solid line in the graph) pretty much all the time, between all devices…

oHR Recording

This trail outing, as mentioned in the video, was a great example of the continuing issue with oHR heart rate recording… independent of brand/sensor.

The Polar Vantage V and Suunto 9 Baro were both on my hands, connected to the same Polar H10 chest strap… and their different connection quality(?) and/or algorithms show some difference in HR recording even so!

Suunto 7 and Garmin fenix 6X Pro both got confused in the cold, with the restricted blood flow to my hands. They both recorded HR that was far below my actual heart rate.

Altitude Recording

In terms of altitude, there is the usual similarity on different levels. I.e., as usual, I did not bother setting the watches to the same starting altitude, so that they showed some difference – and they kept that, more or less.

The altitude profiles recorded are, therefore, still similar enough to be useful… except for an issue of the Polar Vantage V. (Somehow, around the second peak, it overcorrected strangely.)

Suunto 7 and Suunto 9 Baro, by the way, are the two altitude profiles which track pretty much parallel.

It’s always good to have a look at ascent/descent values separately, though:

Suunto 7771 m +821 m –
Suunto 9787 m +824 m –
fenix 6X Pro830 m +788 m –
Polar Vantage V825 m +820 m –

This is a somewhat curious result.

Suunto 7 and 9 Baro really tracked each other very well, not just in the profile but also in the data values. Sure, they may have similar/same algorithms for counting ascent/descent, but that also requires them to have measured and calculated altitude data nearly the same.

The fenix and Vantage results feel quite odd; I am quite certain that there is less ascent than descent on this route, in this direction, first of all.

Between other algorithms and some measurement issues (in the case of the Vantage, as visible in the altitude profile as well), quickly make for such a difference – but the comparison with other data gathered here before looks even more interesting now!

Suunto 7 Battery Life in the Mountains

Somehow, I ended up faster here than I thought I would be (and than before, if I remember correctly). Meaning, I was out for only two hours, near-exactly.

The Suunto 7, at the beginning of this tour, was at 90% battery.

At the end: 45%.

That’s quite the ‘loss’ of battery level yet again. It’s similar to that in easy GPS conditions, so doesn’t look like that must make too much of a difference; I did not change any particular settings (such as turning off Bluetooth, thus disabling notifications).

In fact, since I had not downloaded custom offline maps, the BT connection to the smartphone was necessary to get the map data – which took a few seconds, but not much longer than a Garmin takes to load its onboard topo maps.

The caveat that seems necessary all the time: If you compare the Suunto 7, compare WearOS, with a dedicated sports/outdoor watch, that’s your fault 😉

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