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VO2 Max data must be inaccurate

Kjhman
over 5 years ago

HI there. I have a Fenix 6x pro solar. I've had it for a couple months now and ive been running between 2-5 times per week. I can say with 100% confidence that I am in better physical shape right now than I was 2 months ago. I can now run outside for at least 7-9 miles nonstop. 2 months ago if someone offered me a million dollars to run nonstop for 7 miles, I wouldn't be able to do it. Probably collapse breathless after 2 miles or so. The majority of my completed runs that I have been logging over the last few months say that my activity is either maintaining, improving, or significantly improving VO2 Max....

The thing thats driving me absolutely nuts is that my VO2 max number keeps dropping. 2 months ago it was like 50 and its just been going down every so often and now its at 43, down from 44 that it was yesterday, right after I just finished my 7 mile run outside. Its frustrating to me because I know im improving my cardiovascular fitness and its definitely been improving over the last couple months, yet it seems to be reflecting the opposite in VO2 max data. I'm using a Polar H10 chest heart rate monitor. Is there a way that I can just recalibrate that data? Any suggestions would be very appreciated. Thanks guys.

Keith

  • +1 over 5 years ago

    Hi Keith

    I understand the VO2max takes a while to kick in reliably. At beginning probability vo2max overestimated your fitness. As you progressed with your runs, vo2max adjusted to fit your real fitness. 

  • +1 over 5 years ago

    Same here, 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 65 at the moment because I did a sports medical examination last year and I a VO2max of 68 their.

    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 now  half in the 18 minutes but I know I run a 5K now low in the 17 min.

    So garmin has to finetune this algorithm....

  • +1 over 5 years ago

    The VO2Max is not to be taken seriously. Different watches in the Garmin line will give totally different results.

    Everyone I know with a 945/f6 series had their VO2Max drop by ~10% from the previous generation.

    The V02Max result across people is definitely not comparable. On my f6X it keeps oscillating between 45 and 50 every few days. On the other hand, I have a friend who is in the 60s on his f235 and I am was able to drop him on a group run back when we were able to do that sort of thing.

    I don't know what the VO2Max heuristic is but it doesn't work well. It doesn't seem to matter if I use a HR strap or not. I have come to think it is very strongly influenced by to your absolute HR values -- not zones -- at any given pace and weakly influenced by body mass and terrain. My f235 friend, for insance has a very low resting HR and max HR.

    I used to find the f5 VO2Max to be kind of roughly in the right direction but problematic enough to consider it kind of a game. Cross training and brick workouts have always confused the thing quite a bit. The f6 VO2Max I find not to be useful. It doesn't even seem to track with Performance Condition. I have removed the widget from my watch and Garmin Connect because it is just annoying. I wish I could remove it from the post-workout summary, actually.

  • 0 over 4 years ago in reply to brian.reiter

    I agree with this... specifically the described diff. between F5 and F6.

  • 0 over 4 years ago

    I’ve had Garmin watches that had a Vo2Max feature since the FR220 had the values have always been consistent from one model to the next.

    The biggest thing to having any chance of your Garmin Vo2Max value being close to any value achieved through lab testing is to make sure your MaxHR is set correctly. However you have to keep in mind that the Garmin Vo2Max is still an estimate based on pace and your HR relative to the MaxHR you have set on the watch. Even then it’s best to look at the Garmin Vo2Max value as a trend line and don’t think about the actual number very much.

  • 0 over 4 years ago

    F6 VO2MAX isn't accurate is because it depends on accurate measurement of instant pace, which is horribly inaccurate on F6. If the sky isn't completely clear (e.g. there is at least some tree cover) the instant pace is strongly biased towards slower than actual pace. That makes F6 produce lower than actual VO2MAX estimate.

  • 0 over 4 years ago in reply to silentvoyager

    No. That isn’t it. I use a Stryd which provides accurate instant pace. 

    The algorithm is just lame. 

  • 0 over 4 years ago in reply to brian.reiter

    The algorithm comes from here: https://www.firstbeat.com/en/science-and-physiology/fitness-level/

    It is used by many brands, not just by Garmin. Garmin has recently acquired FirstBeat so it is possible it has tweaked the algorithm, but it is more likely it changed the GPS firmware resulting is less accurate instant pace, at least that was my observation.

    I should add that for me too VO2Max has steadily been raising until July or August, and then started to go down, and by now went down by 5. At the same time I'd started noticing new issues with GPS accuracy, for example some Strava Live segments are now failing to end. I think those all issues are related.

  • 0 over 4 years ago

    I upgraded from a Fenix 5 to a Fenix 6 Pro. As a thank-you, Garmin apparently dropped my VO2Max by 3 points. For a while I thought maybe I got asymptomatic COVID that f'd up my heart. But I've been antibody tested. My next best guess is inaccuracy in estimating instant pace. I recently added a Stryd to my kit, so maybe that will turn things around.

    I know it's a pointless thing to pay attention to, but it is demoralizing to see that number steadily drop week after week.

  • 0 over 4 years ago in reply to nonparametric

    we all need a serious group hug

    I went from 50 vo2 to 49 last week