I'm getting VO2 values on days I haven't done any activity?

I do my workouts maily in the gym in winter, strength training and cardio runs on the treadmill (with HRM-TRI), so I don't normally run outside, I only do so every once in a while (once in three months or so) to check my lactic acid threshold which I use as a reference for when I'm on the treadmill.

But I just noticed on my Garmin Connect that in the last three months, for some reason I have VO2 values logged on some days even though I never did any exercise activity outside with GPS in those three months.

And not only that, when I look at those days were there is a VO2 value, it seems it's always on Mondays and I don't even workout on Mondays, on Mondays I don't even get a chance to go for a walk or anything.

I have no explanation for this, does anyone have any idea or experience the same? TIA

Strangely, those VO2 values are not too far of, they are +/-2 my normal VO2.
  • I had the same thing this past Saturday with my 645. I took a rest day and other than taking the dog for a long walk, that wasn't recorded, I didn't do any workouts and my Vo2Max went from 51 down to 48 but recovered to 51 the next day when I ran outside.

    Makes me think it's a Connect thing rather than being device specific.
  • The first activity that I wore my watch for (a walk) recorded a VO2 max of like 57 (my F3 had me at a 43). So I can confirm that weird VO2 max recordings happen at weird times.
  • Former Member
    0 Former Member over 7 years ago
    Same problem here. I have random, VO2max (lower) logged on days where I did not have a run session. Initially I thought it was a measurement from my Vivosport, that also do VO2max estimation, but I do not log any training sessions on that device. I have failed go see a pattern to this, but it is messing up my otherwise fairly straight line. Possibly it may also impact the algorithm behind the training load zone?

    Annoying...
  • If you look once again, it will be obvious that the VO2Max readings are grouped.

    In the 4 week trend, they are grouped into 4 weekly values, labeled with a date in that week - whether you trained on that exact date or not.

    In the 6 and 12 month trends they are grouped into 6 or 12 monthly values, labeled with the name of the month.
  • If you look once again, it will be obvious that the VO2Max readings are grouped.

    In the 4 week trend, they are grouped into 4 weekly values, labeled with a date in that week - whether you trained on that exact date or not.

    In the 6 and 12 month trends they are grouped into 6 or 12 monthly values, labeled with the name of the month.


    No that is not the point,there should be no readings at all whatsoever since no outdoor activity was performed during those months.They are individual readings randomly spread out, there may be a week or month with no reading, and then several consecutive readings, its not a group values for every week displayed as one value on a date of the week. I've had the Fenix5 since launch last year, this only started happening since 3-4 months.

    So the question is, were do those readings come from? another bug? its obvious its not from a real recorded VO2.
  • Former Member
    0 Former Member over 7 years ago
    If you look once again, it will be obvious that the VO2Max readings are grouped.

    In the 4 week trend, they are grouped into 4 weekly values, labeled with a date in that week - whether you trained on that exact date or not.

    In the 6 and 12 month trends they are grouped into 6 or 12 monthly values, labeled with the name of the month.

    True, if you look at the VO2max report in the web service of Connect, but when I look at 4w the training load report, and scroll down to the VO2max report, I have random data points at days when I did not run. And this goes back to the end of October. The biggest difference is a VO2max ten points below my actual VO2max at the time.

    When I look at the 4 week view of theVO2max report in the iPhone app, it also has random data points. The same problem in the app, when I look at the 4w load view and scroll down to the VO2max view. The last four weeks looks like a zig-zag line for me...

    My current VO2max as reported by the watch and Connect (web and mobile) is currently 4 points below my lab tested VO2max. And this feels reasonable since my run yesterday was in non optimal conditions, at the end of a intensive period in my training. But the random numbers pops up on days when I train, but not run... and they are lower.

    I run 2-3 times per week, so I have some 8 to 12 points (plus the random ones) on my 4w view.
  • No that is not the point,there should be no readings at all whatsoever since no outdoor activity was performed during those months.

    Sorry, I didn't read your post carefully enough.

  • Former Member
    0 Former Member over 7 years ago
    I have figured out why I get odd VO2max values from time to time. They are from my Vivosport strap that I use some days (All training sessions are logged on my F5). I did notice, that when I get a moveIQ logged walking session (not a logged session by intention), the Vivosport gives an estimated VO2max from this. Obviously - since GPS is not in use - it is using my input on how many steps I use per km, so it has distance, time and pulse to work with. Because I did see much lower VO2max estimate (up to 10 units below my actual) I checked my stride length this morning and noticed that it was quite a bit off in Connect. I have now adjusted it and will see what happens. I do not know if I would like to have VO2max estimates at all from a walking session, but obviously I get them if I wear the VS strap and having activity tracking on.

    I expect walking VO2max to be lower than running VO2max, so I will check this out, now that I understand where my "odd" numbers are coming from.

  • I have figured out why I get odd VO2max values from time to time. They are from my Vivosport strap that I use some days (All training sessions are logged on my F5). I did notice, that when I get a moveIQ logged walking session (not a logged session by intention), the Vivosport gives an estimated VO2max from this. Obviously - since GPS is not in use - it is using my input on how many steps I use per km, so it has distance, time and pulse to work with. Because I did see much lower VO2max estimate (up to 10 units below my actual) I checked my stride length this morning and noticed that it was quite a bit off in Connect. I have now adjusted it and will see what happens. I do not know if I would like to have VO2max estimates at all from a walking session, but obviously I get them if I wear the VS strap and having activity tracking on.

    I expect walking VO2max to be lower than running VO2max, so I will check this out, now that I understand where my "odd" numbers are coming from.



    Interesting. I have no moveIQ sessions being logged that could be responsible but I do use the HRM-TRI strap when I run on the treadmill and also calibrate the distance recorded by the Fenix5 before saving the session based on the treadmill reading of distance, but I doubt its using the heart strap HR data and treadmill distance I input to create a VO2 value, doesn't seem accurate, treadmill running is not the same as outdoor running (which takes more effort), not to mention that on the treadmill it can't tell when I'm running on an incline vs horizontal. Also the V02 values don't seem to correspond to the days I workout, but rather fall on Mondays, on which I never workout. Weird, I can't figure out what is going on...