Zonesense difficult to understand

Jan Suchánek

@Stefano-M64 I have a similar experience. Big acceleration in the last kilometer and a drop in Zone sense.

Brad_Olwin

@Jan-Suchánek You are going downhill! I bet HR drops or does not change, this seems fine to me. This is a very short segment maybe a bit over 2 min or 3? Not what ZS is designed for. You can find a lot of information about ZS in the videos on this thread.

Jan Suchánek

@Brad_Olwin No, you’re wrong. This part was 400m long with 10m descent. Almost flat. My pace raised from 6:10 to 4:50 and my HR raised from 153 to 170 at the end of interval.

Inge Nallsson

@Brad_Olwin Sorry for a bit off-topic but since you have so much experience with Suunto watches and the app, do you have any idea why my pace curves in the SA are so coarse? In the below screenshot I’ve set it up exactly like Jan’s shot (and this is on Android - which I think his is as well) with a 15 minutes window.

Granted that his pace scale is about twice my own, but that shouldn’t make such a difference. My pace data looks like it only have sporadic data points, but I’ve examined the .fit files and the ‘speed’ entries are logged every second and have normal variations.

I’ve never seen a finely plotted pace curve since I bought the Race S in Dec 2024.

Edit: The pace information while running, on the watch, is without any surprises and shows normal second variations. It’s just the graphs afterwards that lack definition, and frankly make them impossible to use for any insight as to what I actually did speed-wise:

Ecki D.

Those are results from some runs lately. Im not fit in the moment cause off a herniated disc. So no v2Omax at the moment. At the first picture it looks like zone sense has a negativ correlation to the HR but if you look at the other ones it looks more like the Zone Sense diagram is shifted to the left or to the right on the last picture.
Haven’t done a run after the latest update I think.
But maybe some with more insider oder sientific background can clarify this.

Ecki D.

Here the “raw” data vizualized in runalyze for the first run (latest). I think the chart map better to each other. So maybe there is some kind of shift in the app.

Brad_Olwin

@Jan-Suchánek So, I think ZS is working appropriately here. When you start the downhill run, ZS dips as does your HR. Continuing the downhill your HR rises faster at first and then less with a final rise before you reduce effort. ZS takes some time to respond as is well documented here and well documented in the videos. Your interval is quite short! A bit over 3 min?
During the initial drop in HR when you start downhill ZS decreases as expected, then as you continue to increase effort with a 1 to 2 min lag ZS then continually rises and peaks after you reduce effort, again consistent with how ZS works. So I see nothing wrong here.
You are expecting ZS to be HR or mirror HR and ZS does not do that. It is a calculation based on R-R. Your interval is very short and I as well as many others and Suunto state the ZS is not appropriate for short intervals.
I and others here have to keep repeating this point as well as repeat that ZS is not a proxy for HR. If you watch the videos you may get a better appreciation for how to employ ZS in your training.

Brad_Olwin

@Ecki-D ZS is not supposed to correlate with your HR, repeated often here! Watch the videos, the long ones.

Brad_Olwin

@Inge-Nallsson Can’t help you here as I have iOS.

Jan Suchánek

@Brad_Olwin Thanks for Your time and answer! You’re right, the interval is short and the ZS seems to be affected with slowing down before it. I know, that it has nothing to do with HR. I used AlphaHRV before.

Inge Nallsson

@Brad_Olwin Did an experiment today by deliberately walking the first 30 seconds of a recovery run and the resulting pace graph became butter smooth even when zoomed in to a one minute window. Walking pace was ca 12:00/km and the fastest run pace 5:26/km.

This is a very strange app behaviour. Perhaps I should bring it up as a bug in the android section of this forum… But for now a ‘bug fix’ would be to end every run session with some 10 seconds of walking.

The below screenshot is of the first 15 minutes where both the walk and a pace increase are properly discernable:

Edit: Found a conversation about this in the ‘login-locked’ Android section from two weeks ago. Added my own comment today:

“Android - Bad plotting of Pace time graph”
https://forum.suunto.com/post/163977