Suunto ZoneSense

atoponce

@VoiGAS It’s also been problematic for me. I was hoping it would be a good proxy for lactate threshold testing, but that doesn’t appear to be the case. For my workouts, I do Norwegian style sub-threshold intervals of:

10×3:00 @ ~12K effort
5×6:00 @ ~HM effort
3×10:00 @ ~30K effort

I’ve got my efforts dialed in fairly well based on a long history of racing, so I’m confident if I were to lactate test, I would not be surprised by the results. But when I look at the ZoneSense data, sometimes it shows a V̇O₂ max response, sometimes it doesn’t. Even though the paces aren’t changing.

I’m willing to give some grace for heat, fatigue, niggles, and other things, but the data varies too wildly to make any type of reliable or consistent decisions. Sometimes it claims my AnT is around 160 bpm, sometimes 140 bpm. I honestly am not sure how I’m supposed to interpret that.

I want it to work, as it would be great validating how I’m training, but I’m not sure how to interpret the frequent large day-to-day and within-workout swings.

2b2bff

For me I use it on my easy runs and I look at it after the workout. Usually it gives good results for me in those cases.
However, I struggle to make it really useful in races: There you have no 10 minute warmup. Even more so, if it is a trail race, how to make the values actionable if it lags at least 2 minutes?

VoiGAS

@2b2bff Right, I think in a Race the first 10 minutes are critical. A lot of people get too excited and start too fast. This is where I check the Heartrate very often. Not possible with Zonesense in the first 10 minutes and I am also not sure if it would react fast enough too warn me pushing too hard

snow*

@VoiGAS said:

Right, I think in a Race the first 10 minutes are critical. A lot of people get too excited and start too fast

iirc Joaquin Pérez suggests a 10-minute warm-up before the race and saving that session to have a specific calibration for that day. Then you can start the race at full intensity.

raven

@snow said:

@VoiGAS said:

Right, I think in a Race the first 10 minutes are critical. A lot of people get too excited and start too fast

iirc Joaquin Pérez suggests a 10-minute warm-up before the race and saving that session to have a specific calibration for that day. Then you can start the race at full intensity.

I’ve done back to back sessions where the first was 10-15m, ended and started a new session, and ZoneSense still waited another 10m on the second session before reporting.

snow*

@raven afaik if I correctly understood the stuff I’ve read ZS in the next 10 minutes, considering that we start with a higher intensity, would not be able to perform the calibration and therefore, at the end of the 10 minutes, it will use the calibration data previously performed. However, the 10 minutes are still necessary for ZS to allow the body to reach homeostasis.

raven

@snow My overall point is, in my experience, there’s never any session where you’ll get a “live” ZoneSense reading in minutes 00:01-10:00 whether it’s your first session of the day or your second or later session. If you stop and save a workout and immediately start another, there’s still a 10m wait.

VoiGAS

@raven Did you try it with the same activity type for Warmup? So no Crosstraining - Running, but Running - Running?
I heard this should work. Not happy with it as running activities also creates VO2MAX values.

matram

I analysed about 80 of my runs (mostly aerobic) for which ZS had values for the aerobic threshold.

The root mean square error (relative to the mean HR) was 5.6 bpm. The mean HR was 142 bpm. My old (2-years ago) lab-tested threshold was 138.

Unfortunately I think ZS is not precise enough to use to update zone boundaries.

raven

@VoiGAS said:

@raven Did you try it with the same activity type for Warmup? So no Crosstraining - Running, but Running - Running?
I heard this should work. Not happy with it as running activities also creates VO2MAX values.

I more typically do a “walk” startup, then end and switch to “run,” but I’ve done “run” then “run” too and it didn’t make a difference. Admittedly it’s been a bit since I tried “run” then “run” so if an update changed things my info may be out of date but I don’t recall updated talking about improvements to ZoneSense on the Race S.

Now it may be what is being referenced isn’t the ability to get ZoneSense “on” at start of session, but instead, a “run” then “run” might mean you can start the second run at race effort (i.e. no need to restrict yourself to only a warmup) in the first ten minutes, such that you still only see ZoneSense after the 10m mark but the fast start won’t mess up the calibration. That nuance I have not tested and I’d be uncertain how to verify.

Yesterday I did a 2.2km in 18:07 walk with a little “pickups” here and there to make an average 8:08/km pace. ZoneSense measured my aerobic threshold lower than I’d expect, 134bpm compared to my normal 144bpm. Actual HR averaged 123bpm, max HR 146bpm so my pickups did elevate a bit.

When I ended the walk I immediately did a run effort, which was 8m threshold, followed by 8m recovery, then 8m threshold again, for a total 5km in 26:50, average overall pace 5:22/km but “attack” efforts averaged 4:29/km and 4:36/km. Average HR 152bpm, max HR 168bpm. ZoneSense measured aerobic threshold as 160bpm, which is close to what I think of it at 162bpm. It did not make a recommendation for aerobic threshold.

The second session did not “start” showing ZoneSense until after the first ten minutes. I did not rely on using ZoneSense for either session “live” as the first was too low effort to really care, while the second I was more focused on maintaining my attack pace for the work efforts, while the recovery I simply used standard HR and RPE to make sure I was down to zone2 but not allowing myself to get into zone1.

So if the claim is “without that first session, the ZoneSense graph on the second session would be worse,” then perhaps. I’d need a second Suunto device to properly test that, using the first as normal, and the second not recording the walk effort at all and only starting it on the actual run, then compare results. But what I want is a “full” ZoneSense graph starting from session start to session end.