VO2MAX calculator gone??

[dabatey]

The calculator gives me 60/63 for my 2k time a couple of years ago (after 6 months training from zero). Since then I've done 2 years cycling and got much fitter (Cycling FTP has gone from 180ish to 250ish) Garmin and indieVelo both currently give me low 60's based on cycling. Given two years of training between the two readings, one of them must be out I would have thought.

[gvcormac]

The rowing test corrects for sex and also this intangible "training" component.

But it ignores many other important factors, like quality of the stroke and wether your best 2K is actually your maximum effort (which in a sense is the same question wether your MaxHR really is your true maximum heart rate if you were really pushed to the absolute limit).

I don't disagree. My only point is that is you base your calculation on a few observable factors, they can be controlled. So you can get a somewhat repeatable measurement of aerobic capacity, even if it shouldn't be called VO2max. If you base it on an eclectic bunch of hidden variables, as the watch does, it is pretty well useless.

When you talk about what C2 measures, you mean the power calculation in their ergs?

[nick rockliff]

In my experience your absolute vo2max doesn't change once you are highly trained. It just gets lower as you get older.

[gvcormac]

In my experience your absolute vo2max doesn't change once you are highly trained. It just gets lower as you get older.

NOTE: This is not an Attia endorsement.

Peter Attia sells lots of supplements, books, and venison jerky claiming you can raise your VO2 max, and that doing so will decrease your all-cause mortality risk more than smoking cessation.

[Citroen]

Indeed. A running calc gave me 33. I don't treat any of this seriously: if it's a flattering number I'll take it thank you very much, if not then I won't!

So some careful use of https://www.random.org/integers/ would have the same effect.

[JaapvanE]

When you talk about what C2 measures, you mean the power calculation in their ergs?

No, it is the algorithm they published as underpinning their VO2Max calculator on their website. And I agree it is a pretty simple calculation.

When you look at Garmin, their factors are also pretty easy (see https://sportcoaching.co.nz/how-does-ga ... e-vo2-max/ for an explanation). In essence it is the Max Power someone is able to produce for a certain (unspecified) and bodyweight that determine VO2Max, quite similar to C2's approach. The issue here is identifying under what conditions this formula is valid, as for most people their Max Power on a 0.5K is totally different from a 2K or a 21K. And that is where C2's formula's have a bit more clarity as it will always be a 2K. I know for running, a Garmin watch will only generate a VO2Max after at least 1K, which sounds reasonable. But where the boundary is for rowing, nobody knows.

But, we can't ignore that Garmin's formula's have some merit, as they are validated and reach 95% accuracy with a +/- of 3.5 and are reliable (i.e. the number is stable across time).

The issue is that for any max power to be calculated from a sub-max effort, you need some projection to MaxHR to happen. A step-test would be ideal, and rowing with a negative split actually comes very close to that. But with large chunks of steady state you basically are extrapolating noise, which will never yield any decent results. And that is where the true magic of Garmin/firstbeat is (or isn't).

[gvcormac]

But, we can't ignore that Garmin's formula's have some merit, as they are validated and reach 95% accuracy with a +/- of 3.5 and are reliable (i.e. the number is stable across time).

Reference?

[JaapvanE]

Reference?

https://sites.udel.edu/coe-engex/2019/0 ... -estimate/ explains the various references for this number.

[dabatey]

Reference?

https://sites.udel.edu/coe-engex/2019/0 ... -estimate/ explains the various references for this number.

When I see studies like that my first thoughts are. Who instigated the study. Who financed it.

[JaapvanE]

When I see studies like that my first thoughts are. Who instigated the study. Who financed it.

As the main findings were published in a medical journal (where conflict of interest reporting has been mandatory for decades) and no conflict of interests reported there, one may only assume no conflict of interests are present.

[gvcormac]

I'm still looking for peer-reviewed evaluations. The closest I've come is this abstract of a poster shown below, which may or may not have been refereed.

The claim of "95% accuracy with a +/- of 3.5 and are reliable" is from a self-published "white paper": https://assets.firstbeat.com/firstbeat/ ... 6.2017.pdf
I wasn't able to glean enough detail from the method section to understand precisely what they did.

Here's the poster abstract:

https://journals.lww.com/acsm-msse/full ... .2219.aspx

E-33 FREE COMMUNICATION/POSTER - MONITORING FRIDAY, JUNE 2, 2017, 7: 30 AM - 12: 30 PM ROOM: HALL F
Accuracy of Garmin and Polar Smart Watches to Predict VO2max
2667 Board #187 June 2 9
30 AM - 11
00 AM
Snyder, Nikolas C.; Willoughby, Courtney A.; Smith, Bryan K.
Author Information
Medicine & Science in Sports & Exercise 49(5S):p 761, May 2017. | DOI: 10.1249/01.mss.0000519024.10358.0b
FREE

Metrics
Smart watches have greatly evolved since their first release. With advancements in technology, many smart watches can now estimate aerobic capacity. These watches are user-friendly and affordable but there are no current investigations that have reported accuracy to predict VO2max.

PURPOSE: The purpose of this study was to compare actual VO2max values (AMax) to predicted VO2max values obtained from the Garmin Forerunner 230 (230Max) and 235 (235Max) smart watches as well as the V800 Polar smart watch (PMax). The Garmin watches predict VO2max based upon heart rate values obtained during a 10 min, self-paced outdoor run. The Polar watch predicts VO2max based upon resting heart rate variability.

METHODS: Eighteen females (BMI=24.9 ± 3.3 kg/m2, age=24.7 ± 3.8, AMax=42.9 ± 4.8 ml/kg/min) and 24 males (BMI=26.6 ± 3 kg/m2, age=24.2 ± 4.4, AMax=49.5 ± 5.8 ml/kg/min) participated in this study. PMax values for each individual were obtained following a 10 min supine rest and were based upon the different training ranges that can be programed into the watch. Participants then completed a treadmill VO2max test. Within 48 hours of completing the treadmill VO2max test, individuals completed a 10 min, self-paced outdoor run using both Garmin smart watches. Paired sample T-tests were used to determine if there were differences between AMax and the predicted VO2max of each watch.

RESULTS: There were significant differences between AMax and PMax (2.5 ± 6.8 ml/kg/min, p=0.029), 230Max (-0.3 ± 3.4 ml/kg/min, p=0.02) and 235Max (-1.1 ± 4.0 ml/kg/min, p=0.026) in females. In males there were significant differences between AMax values and PMax (-6.0 ± 7.7 ml/kg/min, p=0.001), 230Max (-1.1 ± 3.4 ml/kg/min, p=0.149) and 235Max (-3.2 ± 4.2 ml/kg/min, p=0.002).

CONCLUSION: In females, predicted VO2max values were significantly different from AMax values and the differences ranged from an overestimation of 2.5 ml/kg/min to an underestimation of 1.1 ml/kg/min. In males, predicted VO2max values were significantly different from AMax values and the watches consistently overestimated VO2max (range -1.1 to -6.0 ml/kg/min). Caution should be taken when using these predicted values for exercise prescription especially in men.

© 2017 American College of Sports Medicine

[gvcormac]

I had never before looked at the VO2max estimate on my Garmin. This forum prompted me to look. It says 43.

Recall that the C2 estimate was 42 or 46, depending on whether I claimed to be well trained or not.

The Cooper estimate was 40.

FWIW.

[JaapvanE]

I'm still looking for peer-reviewed evaluations.

Standard SLR approach reveals there are quite some:

• Andrew Pearson, "Predictability of VO2max Using a Commercially Available GPS Sports Watch" (2017)
  
• Stefanie Passler,Julian Bohrer, Lukas Blöchinger and Veit Senner, "Validity of Wrist-Worn Activity Trackers for Estimating VO2max and Energy Expenditure" (2019)
• S Muthusamy, A Subramaniam, "Assessment of Vo2 Max Reliability with Garmin Smart Watch among Swimmers" (2021)
• Luke Daniel McCormick, "Predictability of VO2max from three commercially available devices" (2021)
• Kevin E. Miller, Timothy R. Kempf, Brian C. Rider and Scott A. Conger, "Is the Polar M430 a Valid Tool for Estimating Maximal Oxygen Consumption in Adult Females?" (2021)
• Wei Dong Gao, Olli-Pekka Nuuttila, Hai Bo Fang, Qian Chen and Xi Chen, "A New Fitness Test of Estimating VO2max in Well-Trained Rowing Athletes" (2021)
• Pablo Molina-Garcia, Hannah L. Notbohm, Moritz Schumann, Rob Argent, Megan Hetherington-Rauth, Julie Stang, Wilhelm Bloch, Sulin Cheng, Ulf Ekelund, Luis B. Sardinha, Brian Caulfield, Jan Christian Brønd, Anders Grøntved and Francisco B. Ortega, "Validity of Estimating the Maximal Oxygen Consumption by Consumer Wearables: A Systematic Review with Meta-analysis" (2022)
• Rachelle Foley, "Assessing the Validity of the Garmin Venu SQ for Estimating VO2max" (2022)
• Ren-Jay Shei, Ian G. Holder, Alicia S. Oumsang, Brittni A. Paris and Hunter L. Paris, "Wearable activity trackers–advanced technology or advanced marketing?" (2022)
• Bryson Carrier, Macy M. Helm, Kyle Cruz, Brenna Barrios and James W. Navalta
  "Validation of Aerobic Capacity (VO2max) and Lactate Threshold in Wearable Technology for Athletic Populations"
  

Results seem to vary quite a lot, which might be explained by significant improvements in both sensors and algorithms through the last years.

[Mike Caviston]

VO2 max can’t be estimated very reliably or accurately, as has been discussed. But even knowing one’s true VO2 max (measured directly in an exercise physiology lab) doesn’t provide much useful information regarding performance potential. Yes, there is a general distinction in VO2 max among untrained, moderately trained, and elite athletes (elite athletes have greater VO2 maxes than the moderately trained or untrained). But at a certain level of performance, the variability of VO2 max among athletes is large. If you were to measure all the participants in a major marathon, and look at all those who finish near the 3 hour mark, there would be a fairly wide range of VO2 max values. Put another way, if you looked at the finish times of everyone with a VO2 max of 60 mL/kg, there would also be a fairly wide range. At a given level of performance, VO2 max alone doesn’t tell much because there are multiple factors that affect endurance performance across events that last only a few minutes to marathon or longer. Within a given athlete’s training, an increase in VO2 max may lead to improved performance, but there may be no change or even a decrease in performance despite an increase in VO2 max. (This article provides some background and many similar articles can easily be found: https://physoc.onlinelibrary.wiley.com/ ... 007.143834 )

I have a lot of personal experience with VO2 max. During my years at UMich as a grad student and Instructor in Kinesiology, I administered hundreds of VO2 max tests to healthy but untrained people of many ages, as well as Division I college athletes and some Olympians. At UMich and later during my career with the military, I was able to be tested myself in research labs nearly every year for almost 30 years and to note very clearly the relationship between my own VO2 max and performance. My first test at age 27 produced 71 mL/kg which declined steadily and predictably every time it was measured thereafter. At the age of 40, it was a hair under 60mL/kg. But at age 40 my indoor rowing performances were better than they had been when I was in my 20s, even though my earlier performances were already elite. My training methodology had improved. In my mid-50s, when I was concentrating more on road and trail running than rowing, I noticed that my times were slipping even faster than age would predict, so I reviewed my training methodology, made some modifications, and saw a significant rebound in performance over the next couple years. But my VO2 max didn’t improve.

To sum up, VO2 max is an interesting variable, it’s a nice number to know if you can get it, it’s fun to mess around with different estimates, but ultimately it doesn’t really mean anything if actual performance is your concern.

[HornetMaX]

Rowinglevel also has a VO2max calculator (works with any distance).

My Garmin Instinct 2X estimates VO2max from "daily activities", as I never log any activity on it (it just gets the c2logbook data forwarded for each of my SkiErg and RowErg session). I'm not totally sure of what "daily activities" means however, and Garmin support has been of little help.

I'm also under the impression that the kind of training I do (RowErg and/or SkiErg) influences the measures and actually I seem to have no daily data point (or less daily data points) when I don't use my SkiErg.

I did a marathon training plan for 3 months and the reported VO2max on the Garmin was relatively stable at 63.
Right after I switched to a more HIIT training plan and after a while it went down to 43 and it is now pretty stable around that

Bottom line: the way I use my Garmin watch (not logging activities on it), the VO2max estimation it gives seems to have little value.