Accuaracy of VO2 max

I don't worry so much about the absolute accuracy of the VO2 figure, I tend to focus instead on its changes. So mostly use it as a progress monitor rather than an absolute figure as a badge of honour as such. I think it has a lot of worth if looked at that way

According to the Firstbeat paper

https://assets.firstbeat.com/firstbeat/uploads/2017/06/white_paper_VO2max_30.6.2017.pdf

Table 2. Methods used to measure or estimate fitness level

Correlation between estimated and measured V02max 0.95. MAPE 5%.

Agreed. Although, being 50 and Garmin stating my VO2 max is 74 currently. I'll wear that as a badge of honour lols.

All about the trending.. absolute values may or may not be close to reality, but I find the trending useful.

In case you think the accuracy of the figure might be improved (I've no idea how fit you are!), double check your max. HR settings are realistic - these have quite a bearing on the VO2 max calculation - a common issue can be this can be autodetected from a freakishly high faulty reading - whatever it is set to you should be able to get close to (within a few beats) during an all out effort.

Bloody hell too right! I'm 52 and mine is 54 but on an upward trend :)

I've dropped from 65-66 to 59-60 with my Fenix 6X pro Solar. (I had a fenix 5+ before). I know that it's around the 64 at the moment because I did a sports medical examination last year and I a VO2max of 68 over there.

I have noticed that when you do NOT train in anaerobic zone the VO2 max drops very fast on this fenix. The raceprognose is also to low on the fenix 6 (on the fenix 5 it was much to high), it says I run on a 5K in the 17:46 and a 10K in 37:41, last weekend I ran a 10K race (as training), I came the 5K through in 17:22 and the 10K time was 35:20 and I can go faster...

subra said:

According to the Firstbeat paper

https://assets.firstbeat.com/firstbeat/uploads/2017/06/white_paper_VO2max_30.6.2017.pdf

Table 2. Methods used to measure or estimate fitness level

Correlation between estimated and measured V02max 0.95. MAPE 5%.

If you dig further into the white paper, you will note that the accuracy of the VO2Max estimation is heavily dependent on having an accurate estimate of HRMax for that athlete. If the HRMax datapoint is inaccurate, then the accuracy of the VO2Max estimate declines significantly as well.

Which is not a complaint about the accuracy of VO2Max, but more of a plea that if you are going to attach significance to this, it is worthwhile doing a one-off field test to get a better idea of your HRMax.

That's extremely high. Do you consider yourself extremely fit? The reason I say so is, when I was 42 (now almost 66) I was lab-tested at 62, and was told I was better than most athletes half my age. It was done at a university sports lab, so they had some experience with young athletes.

Last year I read an in-depth piece on this by someone who went into the metrics used by FirstBeat. He also compared several lab results and Garmin (not just himself), and concluded Garmin was typically about 5% low, though it varied from worse to very accurate. That average seems about right by my results.