VO2 Max underestimated consistently

[blinker]

I look at my VO2 Max from time to time and it always says it's well under average. But I've been tested several times and it's actually in the very good range for my age (less than Excellent, but quite good). I do a workout at least four times a week, so there is plenty of data for it to crunch. I've tried to find out the details of how Apple measures it, but no luck. Has anyone else noticed this?

 

[Howard2k]

It's not doing a real VO2Max test, it's just estimating it based on the metrics that it has available. The vast majority of people don't know what VO2Max is, and then a startlingly small number of those who do know what it is get a proper test done for it.

It should be useful for trending though I'd be super surprised if it was comparable to a real world test.

 

[Bichon]

An actual measurement of VO2 Max requires strapping on a mask that measures the oxygen content of exhaled breath. Without that data, all the Apple watch can do is provide an estimate based on heart rate and walking/running pace. While their algorithm takes into account factors like age and medications that affect heart rate, and state-of-the-art machine learning technology is used in building their model, it still is - at the end of the day, just an estimate, not a measurement.

 

[dmr727]

It underestimates mine as well. Since all it can do is look at our heart rate and how it changes during a run/walk, it's really a poor substitute for the real thing. I've stopped looking at it.

 

[frou]

I suspect the opposite because the VO2Max metric from my AW says I have High cardio fitness. But I'm not particularly fit, just thin.

I'm sure the graph over time is positively correlated with fitness but the absolute number that's shown for VO2Max is probably rather inaccurate.

 

[cubodado]

Didn’t measure it properly for myself, but I receive a pretty high estimate for my age group. I should be much faster on a 10k race with that value. Athlytic provides a different estimate for each sport I practice (mainly running and swimming).

 

[blinker]

It's not doing a real VO2Max test, it's just estimating it based on the metrics that it has available.

I understand that, and didn't expect it to be really accurate. But I've had it measured professionally and I'm always in the low 30s. Yet Apple always tells me I'm at 26. That's a significant difference. I did expect it to be better than that.

 

[Kooler]

I’m an exercise physiologist and critical care APRN. My Ultra Apple Watch doesn’t record an accurate, or even close to accurate, maximal oxygen consumption.

 

[GerritV]

Same complaint here. While my walking pace goes up, my VO2max goes down.
I understand it's not that accurate, but it still indicates a trend which, in my case, should go upward.

 

[headlessmike]

I haven't gotten mine tested in a lab, but the trends seem to be pretty comparable as to how I feel even if the absolute numbers are not. I've vastly improved my fitness over the last two years and have seen a noticeable increase in the VO2 number reported by my watch. Currently mine shows a number of 52, which is borderline "High" for my profile, and when I donate blood I see a noticeable drop (3 or 4 points) over a month before the number creeps back up again. When I had Covid a little over a year ago (five weeks of bad symptoms) I saw a 7 point drop which took several months to rebound. So, it's clearly measuring something related to my fitness, but I know that it's probably far from accurate.

 

[arc of the universe]

this is a great thread. thanks.

im not an exercise physiologist.
im just your regular guy who began to use an apple Watch 13 months ago.
here is what i can say (with assurance).

at the most basic level, there is the advantage of awareness.
its a very fiitness oriented device, so when i first reviewed what kinds of data the Watch is recording into the iPhone Health app, i learned about vO2max. that was the most basic level of advantage. awareness.

the next level is during the 1st 5 or 6 months of my increased awareness of all the metrics being recorded, i became more active overall. exercise became part of my daily life. not just something i did every weekend or every so often. but vO2max was not increasing.

the next level of advantage came during the 7th/8th month of usage: specifically about the vO2max data.
like one other person in this thread posted, my activity level had increased. i felt healthier. most of the data agreed with that. but vO2max showed not a lot of improvement. the thing that helped me the most was following the guidance of apple that it provides in the Health app specifically for vO2max. its told me to try increasing my pace; try running / walking up hills. and advice like that.
so i did that. and lo and behold, my vO2max scores began to climb. not dramatically. very slowly increase. i was taking it too easy. i started to challenge myself. i started to track my heart beats per minute during my runs and walks (uphill). i focused on getting into a a higher level of heartbeats per minute for at least a few minutes. and pushing my overall average pace to be higher. and vO2max increased a lot more.

i am 100% in the category of thinking that apple's methodology for me, an average person, who wants to get into better shape, that the trend info is correct. and useable by the person to help in getting fit.
about vO2max: the thing to remember is that it does take weeks or in my case months (!) for the trend to show it increasing. never give up on it. it will get better if the quality of your exercise deserves a better score.

regarding one other data point the Watch provides to the Health app is METs. now thiat is another discussion that also is worth talking about.

 

[TechnoMonk]

If you really want to test Vo2 Max, wear a mask, get on the bike or tread mill breathing in to the tube/Vo2 device to get an accurate reading. Apple and anyother device with out a breathing mask is just an estimation. Diet/Workout and other factors can alter your Vo2 max.

 

[iBug2]

My fitness level is approximately the same as a friend of mine who is using a Garmin watch. My AW gives me 48 Vo2Max. His Garmin gives him 55. That's a significant difference. And the reason I say we are really similar is because whenever we do a run of similar pace, we have a similar HR average, and our age gap is small.

AW always underestimates Vo2Max compared to Garmin watches, that's for sure. But I don't know which one is more accurate compared to an actual Vo2Max test.

However when I check my Vo2Max values using a Cooper test in the track, it's much much much closer to the Garmin number.

 

[GerritV]

this is a great thread. thanks.

im not an exercise physiologist.
im just your regular guy who began to use an apple Watch 13 months ago.
here is what i can say (with assurance).

at the most basic level, there is the advantage of awareness.
its a very fiitness oriented device, so when i first reviewed what kinds of data the Watch is recording into the iPhone Health app, i learned about vO2max. that was the most basic level of advantage. awareness.

the next level is during the 1st 5 or 6 months of my increased awareness of all the metrics being recorded, i became more active overall. exercise became part of my daily life. not just something i did every weekend or every so often. but vO2max was not increasing.

the next level of advantage came during the 7th/8th month of usage: specifically about the vO2max data.
like one other person in this thread posted, my activity level had increased. i felt healthier. most of the data agreed with that. but vO2max showed not a lot of improvement. the thing that helped me the most was following the guidance of apple that it provides in the Health app specifically for vO2max. its told me to try increasing my pace; try running / walking up hills. and advice like that.
so i did that. and lo and behold, my vO2max scores began to climb. not dramatically. very slowly increase. i was taking it too easy. i started to challenge myself. i started to track my heart beats per minute during my runs and walks (uphill). i focused on getting into a a higher level of heartbeats per minute for at least a few minutes. and pushing my overall average pace to be higher. and vO2max increased a lot more.

i am 100% in the category of thinking that apple's methodology for me, an average person, who wants to get into better shape, that the trend info is correct. and useable by the person to help in getting fit.
about vO2max: the thing to remember is that it does take weeks or in my case months (!) for the trend to show it increasing. never give up on it. it will get better if the quality of your exercise deserves a better score.

regarding one other data point the Watch provides to the Health app is METs. now thiat is another discussion that also is worth talking about.

Thanks for your interesting comment, it totally resonates with my own findings.

 

[Rastafabi]

It would be nice if the Watch's values would more accurately reflect real world. I'm consistently below average, even though that's not reflective of my actual fitness levels at all. That said I actually don't care that much about nominal accuracy (really regarding any of the values) as I don't care about comparing myself to others. In the end sports is about doing yourself some good, and if your level of fitness suits you, your just fine. What the Watch is really good at on the other hand in my experience is consistency. I really enjoy seeing my development and trends regarding my fitness and this seems fairly accurate and resembles my workouts during the years, like being less ambitious in the winter months compared to the rest of the year. Also other values appear to be pretty accurate, so there's that. As VO²max is somewhat the most obscure value, as it's not actually measured, but algorithmically calculated based on different factors I think Apple could adjust it's precision with software, and I hope they will.

That said nobody should belittle themself when doing sports based on any data. Doing something as always better than doing nothing, no matter what the numbers say. And as I said; Trends do show quite accurately, so let those be your motivation the keep it up. Your body will most certainly profit. As will your mental health.

 

[GerritV]

It would be nice if the Watch's values would more accurately reflect real world. I'm consistently below average, even though that's not reflective of my actual fitness levels at all. That said I actually don't care that much about nominal accuracy (really regarding any of the values) as I don't care about comparing myself to others. In the end sports is about doing yourself some good, and if your level of fitness suits you, your just fine. What the Watch is really good at on the other hand in my experience is consistency. I really enjoy seeing my development and trends regarding my fitness and this seems fairly accurate and resembles my workouts during the years, like being less ambitious in the winter months compared to the rest of the year. Also other values appear to be pretty accurate, so there's that. As VO²max is somewhat the most obscure value, as it's not actually measured, but algorithmically calculated based on different factors I think Apple could adjust it's precision with software, and I hope they will.

That said nobody should belittle themself when doing sports based on any data. Doing something as always better than doing nothing, no matter what the numbers say. And as I said; Trends do show quite accurately, so let those be your motivation the keep it up. Your body will most certainly profit. As will your mental health.

Of course, the risk of living with a smart watch / activity tracker is getting addicted to its data.
I'm slowly getting over that and -indeed- try to pay more attention to the trends.
Comparing myself to myself yesterday ;-)

 

[3Rock]

I don’t use mine anymore since it’s not accurate. I don’t even use the calorie counter because that to is not accurate. Might as well not even have it on there. Can’t wait for the blood pressure measuring sensor, and that two will not be even close to accurate. The more professional blood pressure devices that you use on the wrist is never as accurate as the one that is used above the arm. The timer is OK though. 🤪

 

[dmr727]

I wonder if some of this is tied into what the watch calculates as our average resting heart rate. I feel like my watch shows mine as higher than it actually is - I live in the city with a three year old - mine fluctuates a lot based on my environment!

 

[blinker]

Well, I appreciate all the input here. At least I’m not alone in this opinion. Not at all accurate as an evaluation of your fitness level, but OK for looking at the trends.

 

[Spindel]

The way I see the AW VO2Max is to not look at the absolute number but to look at the changes I get from being more or less active suring a period of time.

I feel the change/change rate is fairly accurate but not neccesarily the absolute number.

 

[Le Big Mac]

An actual measurement of VO2 Max requires strapping on a mask that measures the oxygen content of exhaled breath. Without that data, all the Apple watch can do is provide an estimate based on heart rate and walking/running pace. While their algorithm takes into account factors like age and medications that affect heart rate, and state-of-the-art machine learning technology is used in building their model, it still is - at the end of the day, just an estimate, not a measurement.

Right - like anything of the sort, the AW is using a formula including various variables that have been determined overall when pushed through the function to correlate with actual V02 Max. But clearly it's not 100% correlation - for some people it will be high, and others low . . . so that's what you're seeing.

Would be good if Apple made available the various statistical measures of closeness of fit, etc.

 

[Saturn007]

Accuracy is an issue for many reasons. I'm often doing walks that are fairly leisurely and so my heart rate doesn’t hit high rates — pretty sure I get penalized for that.

My much bigger complaint is Apple's labeling of the results. It goes from “Below Average” to “Above Average” with nothing in-between. In other words, a .1 jump takes you from being stigmatized as weak, not that fit, and below grade to being a resident of LakeWoeBeGone and on the way to beingthe new Wheaties Champion!

Ridiculous.

They need to add an “Average“ band to mirror reality.

Then, they need to include additional labeling that avoids sudden jumps in apparent fitness— that is, avoid all dramatic change in the qualitative label due to a .1 change in VO2. For example, they could describe or parse the results just below “Average” or just above “Below Average” as something in-between — label it “On the Cusp of Below-Average and Average”.

It'd also be good if they provided detailed directions of how wearers could improve on the measure — even retrospective commentary on where one's performance has been weaker (i.e., “too many leisurely walks” 😁) or has hurt their own measurement or indicator!

 

[arc of the universe]

...they could describe or parse the results just below “Average” or just above “Below Average” as something in-between — label it “On the Cusp of Below-Average and Average”....

you are correct that in the iPhone's Health app graph it is above or below.
however, the kind of "advisement" you indicate is in the Activity app itself, on the iPhone, in the Trends section.
usually its a vanilla type of advise such as "Looking good, arrows are pointing up".
but when you are on the cusp of trending down, in the Trends' vo2max section, above the graph, there are one or two sentences that let you know what is happening with stark bluntness.
i remember i got a rather blunt message that said something like: your trend arrow is going to start facing down unless you "pick up the pace" (my translation). try walking up hills, or increase your walking pace."
i trust and follow those Activity Trend indicators to tell me how i am doing.

 

[leescottdavis]

All watches are inaccurate. Get lab tested. You'll find Apple Watches are typically slightly under, Garmin's are typically slightly over. In the end, they are just guesstimating.

 

[Saturn007]

you are correct that in the iPhone's Health app graph it is above or below.

however, the kind of "advisement" you indicate is in the Activity app itself, on the iPhone, in the Trends section.
usually its a vanilla type of advise such as Looking good, arrows are pointing up".

Thanks for noting that! My VOMax putters along at its middling level — likely due to exercise sessions often being Core Training and Physical Strength Training that aren't excessively taxing. So, I've never gotten a trend for VOMax — nor a prod!

Maybe one day, they'll put something on the Watch itself! With nudges…. My iPhone is usually turned off, so it's only maybe every couple of weeks that I even am looking at VOMax or the Trends. Having it on the Watch would be great!

You'd think with the 32GB of storage space on Series 6-8 and the advanced CPU in our watches that they'd have plenty of room and computing power to display Watch trends, advice, alerts, etc.