Garmin VO2 Max Accuracy (and utility)

I use it to track my fitness, relative to previous measurements. I'm just happy to see the graph go up. I don't put much stock in the a tual number.

Although I'm sure it's better than the body fat percentage provided by my Garmin scale - apparently I've had 7.0% body fat for the past two years.

***...actual number...***

Coffee and a donut wrote:

I use it to track my fitness, relative to previous measurements. I'm just happy to see the graph go up. I don't put much stock in the a tual number.

Although I'm sure it's better than the body fat percentage provided by my Garmin scale - apparently I've had 7.0% body fat for the past two years.

Makes sense to me! Think of it all as relative, rather than absolute... thanks!

As for the scale - haven't owned one in 10 years and don't plan to :)

To echo what a previous poster said, I don’t give heed to the actual number my garmin tells me my vo2 max is, but I do pay attention to the trend of what that number is doing.

As this is a sub-max vo2 approximated, you'll want to make sure your configured max HR isn't set to higher than what it truly is, as your sub-maximal workouts will seem easier to the algo on a %of max-HR, given that it tends to over-estimate, you may want to go slightly below your max HR actual to keep these values closer. Of course doing so would screw up your 'time in zone N' charts so probably best to not do that as those charts become impossible to tweak satisfactorily if your max HR was set a little lower than actual (-5 to -10 range would probably correct the vo2 scoring)

But as others have suggested, trending is probably useful

In my experience, it's fairly close to accurate, but also not useful. Typically I don't see it move much at all with changing fitness. It moves a lot with the weather (summer heat and humidity makes my heart rate a lot higher at similar paces) and with fatigue. Highest values are after races and very hard workouts, and then it will trend down until I do another one. My highest recorded levels do not correspond to my highest fitness, though.

If you're relatively untrained or out of shape, it's probably more accurate in showing trending fitness, but if that's the case, then you definitely don't need a fancy watch to tell you you're getting faster; it's obvious.

Sit and kick wrote:

As this is a sub-max vo2 approximated, you'll want to make sure your configured max HR isn't set to higher than what it truly is, as your sub-maximal workouts will seem easier to the algo on a %of max-HR, given that it tends to over-estimate, you may want to go slightly below your max HR actual to keep these values closer. Of course doing so would screw up your 'time in zone N' charts so probably best to not do that as those charts become impossible to tweak satisfactorily if your max HR was set a little lower than actual (-5 to -10 range would probably correct the vo2 scoring)

But as others have suggested, trending is probably useful

I don't know where the value comes from, but it suggests 195 for me. I reset all the other HR zones to default, as well!

800 dude wrote:

In my experience, it's fairly close to accurate, but also not useful. Typically I don't see it move much at all with changing fitness. It moves a lot with the weather (summer heat and humidity makes my heart rate a lot higher at similar paces) and with fatigue. Highest values are after races and very hard workouts, and then it will trend down until I do another one. My highest recorded levels do not correspond to my highest fitness, though.

If you're relatively untrained or out of shape, it's probably more accurate in showing trending fitness, but if that's the case, then you definitely don't need a fancy watch to tell you you're getting faster; it's obvious.

this. having used it for a year, I concluded it's fairly useless. it's not just the level that's off for me as for many others, neither does it capture the trend. it all depends on which kind of workouts you are doing, it's only accurate if you're doing similar workouts in similar conditions. but then, you don't need it, you can just compare times / pace directly.

Does weight play a part in the algorithm? Because if it does, then runners like me who have a bit of muscle are going to be penalized. I guess if you hooked it up to one of their scales which show body fat and muscle percentage then it might be smart enough to take that into account.

It doesn't make much sense to me. I'm finding that after an interval or a 1K time trial it usually raises my score, but then when I do an easy run it lowers it, no matter that recently my heartbeat on my easy runs has averaged about 10 beats a minute less than previously.

Also, my VO2 max is apparently 45,46, or 47 (depending on whether my last run was fast and short or long and easy) and when it's 45 it says it's only 'fair' for my age :( yet when I Google most VO2 max charts they usually say that even 45 is very good for my age band.

Useless. If you have done hard running on flat roads and then suddenly switch to hilly terrain your Vo2max number will go down, since your speed at a certain effort will be lower.

As per my post above, the bf% on Garmin scales is a joke - a well-known problem. It basically gives a reading of 7.0% to anyone putting in moderate to heavy mileage.

It doesn't even measure heart rate accurately

The VO2 Max value my Garmin tells me ranges from 63-67 depending on how I am feeling. I've been noticing that my HR is a little different than most runners - resting HR is around 40, but easy runs at 3:50-4:15/km pace I hover around 145-155, which I am guessing makes the watch think I am out of shape. My max recorded HR is 193

I recently had a VO2 max test done on a bike and they recorded a value of 71. During this test, I was only able to get my HR to 180 since my quads gave out before my breathing and heart could really get exhausted, and the testers said that since I train as a runner, my actual value would probably be around 3+ the bike value, so 74.

So all together, I don't think the garmin does a very good job at estimating

I will say the estimation is pretty bad as your VO2 changes each day, week, and month depending on what kind of work you are doing.

I'm currently experimenting with a long interval block and so far found my VO2 dropped 11 points after 1 month at sea level with 20% of original mileage, after 4 weeks of 2-3d/wk 6x5min intervals w/ 2.5min rest it jumped 12 points, and a test last week had a 0.5 point decrease.

Interesting info but I think you would find similar info from a time trial 5k race every 1-2 weeks.

I have the 235. Mine is typically 55-59 and garmins time predictions are always way off by minutes. Typically it estimates I’m in 1730-20 min 5k shape when I recently ran 430, 16 flat and 33:30. My max HR is based on my top recorded HR during 800 - 10k races (190bpm). Not sure what 55-59 should correlate with but I don’t trust much with the watch outside time and distance. Even the indoor run setting is typically .1 to .3 miles off every mile. Hopefully this info gives u some insight