Suunto ZoneSense

Brad_Olwin

@VoiGAS This looks much better. You have some great comments from @Ghost and @far-blue. I think ZS is best suited for longer efforts and racing as stated. Using for intervals is tough, they need to be longer intervals.

Mitch9

Yesterday I had a race and the ZoneSense data (not realtime) is not representative (mostly aerob green but pushed really hard). I think it is because I didn’t record the warm-up and started the watch at race start.

Similar experience?

Sergei Ladeishchikov

Yes, the experience of using ZS at the beginning of the race is interesting

Mitch9

But some wrote here that they use ZoneSense in races. How is this possible? And I don’t want to start the activity before warm-up!!!

Maryn

@Mitch9 I think that the word “warmup” in the case of Zone Sense does not refer to a gentle run, it’s just that the algorithm needs 10 minutes of running (any kind of running, as long as it is continuous and not short intervals) to start working properly. Please correct me if I am wrong.

Mattg576

@Maryn

@Brad said above that “ZS needs a solid easy aerobic warm up of 10 min.”

I’m interested myself as I have some races coming up that I want to use ZS on but know they will
have a banzai start…

Christoph13

@Mattg576 I have a race coming up myself and will simply start by feel and pace as always and 30 minutes or so into the race start looking at the Zonesense page.

One thing I am still not clear about myself where in the yellow zone I would ideally want to be for a well-paced half marathon.

The_77

@Christoph13 on this I did a 1/2 test last year, with a ten minute warm up including some strides - so not from the gun but was almost all orange, and my last 10ish race was all orange, no red. Not that I really checked during the race since it was traily and knotty underfoot.

Christoph13

@The_77 Thanks for that but without knowing how far below the threshold between Z4 and Z5 you stayed it is impossible to know the answer to my question.
It is clear that one would want to run a half marathon in the yellow zone but the tricky bit is what you should strive for on the Zonesense data page in real time.

This is a race last year that I did and felt that it worked out well but a) I only looked at the Zonesense data after the race and b) could I have pushed a little harder still (while making sure to not overdo it) by drawing realtime feedback from Zonesense? That is basically my question.
https://forum.suunto.com/post/154967

The_77

@Christoph13 it is worth noting, now that I remember, that I was sick leading up to this - hence these HR zones:

I might be no further help, sorry!

Brad_Olwin

@The_77 said in Suunto ZoneSense:

@Christoph13 it is worth noting, now that I remember, that I was sick leading up to this - hence these HR zones:

I might be no further help, sorry!

The Z4/5 interface in this example is set too low. You should not be able to maintain Z5 for 30 minutes!

Brad_Olwin

@Maryn said in Suunto ZoneSense:

@Mitch9 I think that the word “warmup” in the case of Zone Sense does not refer to a gentle run, it’s just that the algorithm needs 10 minutes of running (any kind of running, as long as it is continuous and not short intervals) to start working properly. Please correct me if I am wrong.

I will check on this but I believe it needs an aerobic HR.

Mitch9

@Brad_Olwin This is the graph of the race:

The_77

@Brad_Olwin hence the caveat about being ill - I would never normally be able to do that.

Brad_Olwin

@The_77 Ill or not, Z5 can be sustained for minutes not half an hour. Your Z5 is too low, when ill you shouldn’t be able to reach Z5 at all.

The_77

@Brad_Olwin Suunto’s docs suggest setting threshold at the Z4/Z5 interval, which if I do based off average threshold length efforts, is usually 165/166 based off of prior races - and my average HR for this race of 40 mins was 167, which is basically that spot on. If I changed if by 2/3bpm to 167/168 it would entirely flip the percentage zoning.

far-blue

@The_77 maybe I’ve misunderstood what you wrote but it sounds to me like you are expecting ZS to align with the HR zones you set in your watch which are themselves based on generic ranges like 60% or 70% of HRR.

To be clear, your HR zones should be set based on ZS measurements, not the other way round, if you do still wish to use HR zones. ZS needs about 3 mins to stabilise after a pace change so may I suggest you try something like:

5 mins warmup
5 mins at what you consider threshold pace
2 mins recovery
5 mins at ~ 10s/km faster than the previous rep
2 mins recovery
5 mins at ~ 10s/km faster still
cooldown

hopefully that would push you just into vo2max and give you a first indication of where ZS thinks your LT2 point is. Doing a few more workouts at around that pace or HR will give you a general idea how to adjust your HR zones.

I know everyone is different but just to give you some idea, here’s my numbers.

resting HR (standing): 54
max HR: 187
Z2 -> Z3 (LT1 - where ZS goes green to yellow): 153
Z4 -> Z5 (LT2 - where ZS goes yellow to red): 172

Brad_Olwin

@The_77 To add to @far-blue. Threshold is typically what you can sustain for 20-30 min. A Cooper test for running can help find your LT as well. I cannot sustain Z5 for very long and certainly not 30 min. For running a 40 min race, I would think the HR is likely less than threshold, that is a fairly long time. Have you done a Cooper test?
For cycling possibly a bit different, I used to have my threshold for a 40 min TT. F

Ghost

@The_77 According to Suunto’s model, the anaerobic threshold lies at the transition between Zone 4 and Zone 5. Zone 4 typically spans 94% to 99% of threshold heart rate, while Zone 5 begins just above this point and extends to maximum heart rate.

Zone 5 represents maximal intensity and is characterized by high anaerobic demand, rapid lactate accumulation, and limited sustainability. Time spent in this zone is inherently short due to its physiological demands.

Prolonged durations in Zone 5 are not practical nor intended in training programs. Instead, it is strategically used in short intervals to enhance maximal aerobic capacity and anaerobic power.

Physiologically it is virtually impossible to sustain Zone 5 intensity for 30 minutes—even for elite athletes—because Zone 5 corresponds to intensities at or above VO₂ max, where lactate accumulation, anaerobic energy demand, and cardiovascular strain exceed the body’s capacity for prolonged effort.

Therefore, if a race result indicates 30 minutes spent in Zone 5, it strongly suggests a miscalculation in zone definitions—most likely due to an underestimated threshold, like @Brad_Olwin said.

The_77

@far-blue said in Suunto ZoneSense:

maybe I’ve misunderstood what you wrote but it sounds to me like you are expecting ZS to align with the HR zones you set in your watch which are themselves based on generic ranges like 60% or 70% of HRR.

Yeah no not at all, I don’t expect any alignment, I was just showing something from my side. My zones are very different to you, our resting HR is similar, but I typically see green to yellow anywhere from 125 - 140, and I can count the number of times I’ve seen V02 max region pop up on one hand, I’ve never got an LT2 from ZS. Max HR is 182, I hit 180 maybe 1/2 times year, I just have an interesting heart

@Brad_Olwin said in Suunto ZoneSense:

For cycling possibly a bit different, I used to have my threshold for a 40 min TT. F

That is more or less what I’m used to from my experience as a cyclist first and runner second, the 95% of FTP for a 20 minute test stuff.

As I said mind, if I change it up to 168, it’ll flip the graph entirely, I’ll see what difference it makes in the next race.

/edit: I must have forgotten to change it last year tbf after the last time intervals.icu advised to do so

Extra edit: did the anaerobic S+ test this morning, wanted to throw up at the end, as is proper results vary from what you’d expect as you’d expect with intra-day HR variation, Runanalyze says HRV data is all good.