Suunto ZoneSense

Ze Stuart

@halajos it’d be interesting to see a plot comparing HR, HRV, and ZoneSense.

halajos

@Ze-Stuart here are some screenshots from SA. The first one is the first hour of the race, when ZonSense showed I was in aerobic zone up to about 150 BPM. I haven’t had a threshold test since last year, at that time my AeT was measured 148 BPM. For this race ZoneSense tells my AeT was 140 BPM. The second screenshot is from later on the race, when ZoneSense shows I go from aerobic to anaerobic when I decrease intensity and my HR drops. Maybe it doesn’t work well with fluctuating intensity around the threshold.

far-blue

In the video explaining how ZoneSense works, Suunto basically describe how there are changes in the patterning of the variability between beats that the technology is looking for. So as the variability (the scale of variation in time between beats) shifts from quite high to more narrow (aerobic to anaerobic) and then again to more of a negatively correlated pattern (VO2Max) ZoneSense spots the pattern change and interprets it. However, I do think there is a level of personalisation / tuning going on as you use it more (and I suspect this doesn’t happen on the watch but in the app and is then sync’d back as a set of tuning values).

Also consider what happens when your actual heart rate changes rapidly - in these cases it would be hard for ZoneSense to differentiate between high inter-beat variability (i.e. aerobic zone) and a rapidly decelerating or accelerating heart rate. I think that’s what causes the sudden drops into aerobic on ZoneSense when you accelerate into an interval or switch from running to walking.

Ze Stuart

@far-blue this is why I was thinking it would be interesting to see @halajos’s HRV data as well as the ZS and HR data.

Ecki D.

@FCDsh said in Suunto ZoneSense:

I have noticed that the ZoneSense DDFA index values are displayed in the range 99-101, although the screenshots here in the forum show values with “0.x”. Does anyone have an explanation for this? Also, I can’t explain why the workout is classified as 100% aerobic even though I trained in higher heart rate zones? Does the algorithm need to learn more here?

Same here, was trying to get a measurement for anaerobic threshold and was running in Zone 5 (160bpm+ for me) in for about 10 minutes but suddenly no HR was shown anymore, even if it seems to be recorded and I only got 8 seconds in vo2max.
At the moment I can’t say ZoneSense seems very reliable to me but it has been my third run with it up to now.

Brad_Olwin

@Ze-Stuart A deep dive in the HRV data would be necessary, this would not be obvious from the HRV readings. Kanniainen et al. - 2023 - Estimation of physiological exercise thresholds based on dynamical correlation properties of heart r.pdf

pilleus

For me it seems to work correct (as far as I understood the YT video from Suunto).

Here two screenshots. The first from yesterday with a more anaerobic workout on the kickbike, the second from today with an aerobic and relaxed bike ride for recovery.

I had the live ZoneSense display with the option heart rate and ascent and I was able to react immediately by shifting one gear down at the moment the anaerobic state was displayed to come back into the aerobic state. No need to react to the heart rate.

dulko79

A new beta for ios just popped up. I did indoor cycling the other day, no ddfa index was calculated. Now I can see ddfa index chart in the app, even aerobic threshold was detected. I used garmin hrm pro chest strap for the activity. I connected the strap to vertical first then to zwift. It seems there has been improvement in the suunto zonesense.

Ze Stuart

@Brad_Olwin sure, it’d still be interesting to see it alongside the rest of the data.

ZS equivalent of IT troubleshooting steps 1 and 2: is it plugged in, did you turn it on?

droopsio

@droopsio said in Suunto ZoneSense:

Hi,

I have a problem with an app on the watch (Suunto Race S). As you may see on the photo, graphic widget display never changes from green to yellow/red - even in case, that I’m running with higher intensity.
After the workout is finished and saved, in the summary presented by app you can see, that I have been yellow/red zones, but it is never displayed on the watch while doing activity.

Additionally to this - for the whole time, I have a notice about warmup calibration.

Is it a bug for Race S series, or there’s something wrong with my watch?

In the example photo you’ll see, that some part of activity was made with higher intensity but it was never presented with marker and color (nor the stripe or edge).

@Brad_Olwin can you pls advise reg this problem? I did few more runs and each time it is the same - it seems, that it is not working with Race S or my wach?

halajos

@droopsio do you have any other Suunto+ activated or intensity target set? I had issues with ZoneSense when I tried to use different features at the same time.

kriskus

@mlakis I had very similar results. I can’t say that the intervals were short in my case - I did a 4x1200m session at around 4:00/km pace (that’s above my threshold pace). HR data seems correct (black line in the picture), while ZoneSense data shows the same as in your case. It goes down during the interval and high up during a 3’ pause between each session (green/yellow line). I was using Polar H10 sensor. Overall, this feature looks promising, but doesn’t give meaningful data as of yet or perhaps I don’t understand the idea of its functioning.

Mff73

@kriskus and others,
i noted the same, and i would love to understand how to use it (if usable )
there was here https://forum.suunto.com/post/155245 this mention about a 3min window.
Might we consider that ZS is indicating the past 3min reflect of our effort ?

droopsio

@halajos I have climb enabled, but before zone sens I’ve had also 2 S+ apps active. I don’t think that climb should interfere with ZS (?)

kriskus

@Mff73 Well, in my case it would probably be a little more. Each interval was around 5’ long and ZS only starts rising just before the 3’ pause. It looks just as if it was somewhat shifted vs HR.

VoiGAS

@kriskus Looks you have problems to reach the red zone - me too. Made a 3/9 minute FTP test today. In the All Out sections I thought I would spit my lungs out, but nothing red in Zonesense and also no VO2MAX threshold as I didn’t cross it

herlas

@kriskus such long delay is odd, haven’t seen that in my use of ZoneSense. 1200m reps almost fall in the short side for ZS to represent the accumulated fatigue but should be doable. In my experience, when talking intervals, about 800 meters in, it starts to show realistic effort levels. BTW it’s also known/expected that after quick changes of pace (from jogging to start of interval) ZS will drop to low green and then start going up as rep progresses.

Looks like your baseline collection (first 10 mins) were done in yellow already, recommendation is to go easy on those 10 initial mins, mostly aerobic to get a good baseline, when effort increases, it’s going to be compared against o that baseline if it was captured at all, otherwise previous day(s) captured baseline.

Łukasz Szmigiel · S9PP 2.37.48

@VoiGAS try a medium speed 30 min run to reach base exhaustion and then slowly but steadily push towards limit for as long as you can.

kriskus

@herlas Well, the first ~2kms were in fact a warm-up, and all done in the green zone. My HR zones were set up after a performance test, though it’s been a while now and they might need light adjustment.

kriskus

@VoiGAS Actually, today’s run wasn’t meant to get to the red zone. Recently I did a treadmill run to get to my max and I reached the red zone in the end: