Garmin VO2 Max | 80/20 Endurance

Garmin VO2 Max

Viewing 14 posts - 1 through 14 (of 14 total)
  • Author
  • #13830

    Does it seem like Garmin’s VO2 max is too quick to move in either direction? I’m pretty much resigned to the fact that any easy run I do on a hot/humid day will result in my VO2 max being lowered. I’ve also had times when I’ve one a longer fast run that gives me an increase, followed by a short cool down (1 mile or so) that drop it back down.

    It seems like there would be a better way of calculating this. Maybe averaging over several workouts. It’s not like I’m changing my workouts based on what Garmin says my VO2 max is, but this can still be irritating. Has anyone else had this experience?

    Matt Fitzgerald

    This is another example of a measurement problem. If this feature didn’t exist, you wouldn’t be concerned about your fitness, but because it does exist yet doesn’t reliably represent your fitness, you are concerned, or at least irritated. Your best move is to ignore the feature, as I always did. If you can’t do that, make comparisons only between workouts of the same type, and even then, take every number with a gigantic grain of salt.


    With my first training plan I let Garmin recalculate my LTHR and pace settings all the time. Eventually I calibrated myself off the plan.
    My suggestion is not to take Garmin suggestions that seriously. If I would listen to Garmin I would sometimes need to rest for 2-3 days after intense run but 80/20 plan says that tomorrow is training day. I do the runs and garmin actually finds me productive although it said I should rest.
    Just listen to your body and follow the plan as close as your body lets you. Do some talk tests or 20min tests to reassess LTHR and take care of you muscles and mobility to stay injury free.


    Thanks for the input. Yeah, I can just ignore it. As soon as I wake up on an easy run day and see a higher temperature than usual, I just know it’s probably going to drop.

    As far as the Garmin recommendations, I always took those to mean that you shouldn’t do another intense workout during that time period. The way my runs are scheduled, that’s never been an issue. I guess Garmin could be somewhat helpful to the person without any real direction in their training. But if you listen to your body, like you said, you should be fine.


    I watch the estimate as a curiosity. I think that as time goes by the tracking of bio activity will yield useful tools in the not too distant future.

    The VO2 estimates do oscillate based on activity. I’m currently entering the 3rd week of race specific training on my 80/20 10k plan and have watched my VO2 estimate jump a couple of points since I started the plan. If you pay attention to the race time estimates you will notice that there are variations even without a change in the VO2 estimate, so I think it is possible to straddle the estimate on a daily basis and not see a VO2 change.

    If I were to listen to my body I would never progress – even the 80/20 training is damn hard. The VO2 is only one estimate of potential, but it does offer some motivation when I’m in that well of fatigue.

    I get more excited when Garmin tells me there’s a jump in my lactate threshold. It gives me some actionable guidance for daily training.


    Charles – Interesting. I guess I haven’t paid attention to the race estimates, but I’ll check those out. As far as listening to your body, I find that I do better if I do the easy runs by perceived effort and then try to hit my targets on the faster workouts. But yes, some of those workouts are pretty tough. I followed one of the 80/20 programs for my last marathon. Not easy, but it paid off.


    I like to follow the Garmin measurements but I don’t live by them. Funny that yours doesn’t seem to address weather conditions, I think mine does a pretty good job of accounting for heat/humidity. Hey, does your watch have the Heat Acclimation score? Maybe if it doesn’t have that feature it won’t be able to let it influence the correct VO2max score. I’ve been sitting at 100% acclimation according to Garmin since early June, that’s what happens when conditions are constantly sitting at a dewpoint of 67+ when I run.

    Back on the Vo2max score: Currently I’m on a trend of Vo2max going up according to Garmin, so I’ll take that as a positive (ha ha) but I do typically ignore it when it says things are going south. I have done a ton of low-zone work in previous training cycles, the FirstBeat algorithms that Garmin employs REALLY do not like that style of training!

    Also note that Garmin’s algorithms depend on an accurate estimate of your max HR. If MHR is listed as too high, it will inflate your Vo2max score, and vice versa. I like to use the race estimates it gives to see how realistic the score might be.


    Alan, now I am curious.

    I don’t do marathons, and despise running more than 90 minutes. Garmin seems to have picked up on this in my training data.

    When I compare my Garmin race predictions with age-grade performance standards I get:

    5K – 85.42%
    10K – 81.11%
    Half Marathon – 72.84%
    Marathon – 66.76%

    Admittedly everything would need to come together to actually meet any of these standards. But generally the fall off in performance leads me to believe that the Garmin algorithms are giving me an objective evaluation of my potential performance at the various distances. The curve might change with training at higher volumes, but I really don’t want to go there…

    As a marathoner, do you see the predictions skewed towards the longer distances?


    The VO2 max number on my Garmin goes up and down like a yo-yo. After a hard workout it pops up but then drops down again – that’s not realistic in my view. I’ve seen it move up 7 points after 1 ride. Consequently I generally ignore it as it’s not providing me with any meaningful information about whether I’m improving or deteriorating in fitness! I use the fitness tests in the program to compare power output for the run and bike, and pace for the swim as my measure.



    The worst drop I ever saw was when I was in New Mexico and decided to track my hike to the top of the mountain. The elevation was much higher than where I live, plus it was a steep incline. I guess Garmin only accounted for pace and heart rate, and consequently must have thought that I was completely out of shape!


    Yes, the algorithm definitely takes into account your long runs in order to estimate your marathon time. I’m not sure (but inclined to think) that the 5K estimate is also skewed towards hard/shorter efforts in training but definitely the marathon will not estimate correctly until you start doing 17-18+ mile runs.


    Something is amiss.

    From my read of the First Beat white paper on their approach it is based on heart rate variability and running speed. They don’t talk about a capability for bike or swimming VO2 measurement.

    There is a summary description here:


    Maybe there is a caution here to make sure non-running workouts are properly identified as such before saving?


    You can get a bike Vo2max recording but it requires having a power meter. I’m not aware of any Vo2max for swimming in Garmin’s suite but maybe I missed it since I personally don’t swim unless I have to.

Viewing 14 posts - 1 through 14 (of 14 total)
  • You must be logged in to reply to this topic.

You have races.

We have plans.



- Access to all 80/20 plans

- TrainingPeaks Premium

- Workout Library

- 80/20 Endurance Book


30 day money back guarentee

Unlock your full potential

with our subscriptions