Weird calculation / estimation of VO2max
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There seems to be a problem with a calculation (estimation) of the statistics that many sportsmen are closely monitoring - VO2max. According to Cooper test (SuuntoPlus app) estimation, based on a distance achieved during a 12 min run at a maximum effort, my value is at about 44 (derived from 2460 m distance achieved, corresponding to values/distances mentioned by many various sources). However, the general VO2max estimator within the watch (in my case Suunto Vertical Titanium Solar) shows me much higher values and even within the same activity / run when Cooper test was done, it showed 46.1… Furthermore, it shows even bigger values of VO2 estimates based even on activities like walking(!), in my case often above 47 or even close to 48. I know - all of these are just estimates - but there is quite a huge difference in physical condition of an athlet with a VO2max of 44 and 47. I am really unable to overtake me running with a maximum effort by 180 metres during a 12 min run (i.e. achieving 2630 m instead of 2460 m recorded by me) or to improve my pace from 4 m 53 sec (per 1 km) to 4 m 34 sec, corresponding to VO2max of 47.5… Moreover, given the scale used in a graph on a left part of the screenshot, you can see almost nothing there…
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@MartinZ keep in mind that your watch is not a medical instrument. Also were you wearing a HR strap for mesures ?
I can share you my experience with VO2max estimation : i always run with hr strap, do a lot of trail running, sometimes road races.
My watch used to estimate my vo2max around 57, now it’s more between 55 to 56 even I’ve never ran so fast
I went for a medical measurement two years ago, my vo2max was measured at 59,5.
Meantime, race time estimations in my watch are not far from reality.
So, 2 or 3 points of vo2max between theory and what your watch gives you may seems to be a lot, but I would rather say it’s a « good » estimation. You should probably more take concern about long term tendencies -
@Tieutieu Thanks for the information. Yes, I always use the HR belt and how could be seen on the screenshot, measurement of both HR as well as distance (GPS data) during my typical interval training is really perfect - congrats, Suunto! However, when returning to VO2max estimates (I know, exact values must be measured in a lab), values given in a standard way by the watch itself are far from values produced by traditional VO2max approximations presented by various sources / methods, giving, however, similar results (e.g. by Cooper, based on 12 minut run or Balke, derived from 15 min run). Furthermore, when watch gives me a VO2max estimate just based on a slow walk with a pace of 11 minut per 1 kilometer, it seems to me really strange…
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@MartinZ I wanted to add that I noticed something similar - a distinct pattern - the easier my run is, with more breaks and less effort overall, the higher VO2max estimation is. When I have a truly good performance in my opinion, my VO2max estimation is always the worst.
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@sky-runner @MartinZ absolute VO2max estimates by wearables were scientifically shown to be not really accurate. The underlying algorithms try to estimate your VO2max by looking at how fast you can run at a given intensity. Then they look at databases that correlate the estimated race time to a VO2max value. This correlation though is pretty individual.
The correlation between heart rate and pace is also often not linear at very low speeds/walking, leading to values that are not in line with faster runs.
Also when you take breaks and pause your watch, your average heart rate in the end is lower while your average pace stays the same. Then the algorithm thinks your are able to run faster at a lower heart rate/intensity and gives higher VO2max values and race predictions.
Also running with a lot of elevation does not really work as in that case speeds are low while intensity is high.You can though use the development of the predicted VO2max to observe trends in your own training status as your individual correlation is quite robust if you compare the same runs or maintain similar training patterns.
FYI: if you lower the heart rate value between Zone 4 and Zone 5 the values will instantly go down as then the algorithm thinks you are closer to your maximum effort. So keep your zones the same if you want to observe trends.
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@brave_dave I don’t think modern watches use pace vs. HR equation to estimate VO2max. It should be either grade adjusted pace or perhaps running power, which is based on the accelerometer data. That’s what Garmin indirectly confirmed when they announced VO2max changes to support trail running.
In my experience with Garmin, many times, estimated VO2max increased after running a gradual uphill if it was at a runnable grade. But a very steep uphill that I had to hike often had an opposite effect, which pointed to the formulas calibrated for low grade runnable terrain. Correspondingly Garmin’s grade adjusted pace feels horribly wrong on a steeper terrain.
Overall, I think that Garmin does a better job at estimating VO2max. Garmin only considers a sustained effort that lasts over certain duration and where you HR exceeds 70% of max HR or something like that. With Suunto the opposite seems to be true.
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@sky-runner yes, you are completely right. They probably use NGP but even that is an estimated compensation that does not work for everyone and also not on every terrain/slope.
Definitely, separating trail running and normal running is a must and also take out walking activities. Also manually excluding activities where you know that they aren’t reliable would be really nice.
I also asked for these feature in multiple forum posts but I don’t think Suunto reads along or cares.
