Is it possible to see one or two decimals for VO2 Max?

AndersB said:

I want to see the trend from training to training

It's quite useless to monitor VO2max on a daily basis, and the point is that the changes you see doesn't represent an actual change in your fitness level - it's mostly just a representation of the accuracy of the estimate.

But this is still a calculated estimate of Vo2Max and your actual fitness doesn’t vary by a decimal point or two from day to day despite the watch calculating it with every activity.

If you run on Monday and the Vo2 value is 55.8 and the weather is a little bit warmer each day the rest of the week your Vo2 value could go down by a decimal or 2 each day just because your body temp, and therefore your HR, would be higher. Did you lose fitness over the course of the week? No. The way the stat is presented now it would’ve told you that your Vo2 is 55 the whole time and that would be more correct than any variances of 0.02 in the bigger picture.

I love having stats to pour over and Vo2Max is one that I do pay attention to. But this particular feature is something that is really only good as a long term trend. As in seeing how much it changed over the course of an entire training schedule, or went down after taking a break.

R_Tellis said:

this particular feature is something that is really only good as a long term trend

I don't disagree with this, but want to point out a nuance in what I think the OP is trying to do, and maybe question how long is long term. There's certainly noise from day to day, for the reasons you point out as well as the devices not being totally consistent with the value they produce for runs of different lengths. That said, the values your watch delivers are filtered from multiple days of exercise anyway, they are not computed from that single activity (try playing with Runalyze, which offers you a VO2max calculation from each activity along with the values read from the files - you can see much wilder variation in the per-activity values).

But there are also trends to be seen over a week or two which aren't apparent with the truncation. I would completely reject the idea that there's any value in the second decimal place. But with the first - if the internal value changes by +0.4 from 52.3 to 52.7, that will gradually pop up as moving from 52 to 53. 51.8 to 52.2, same change, but no change in the integer value. 

I'm in a discussion about this on another site, and nobody there is assigning meaning to changes from day to day - but we are interested in looking at trends over a few weeks which aren't apparent from the integer values, and in looking at the underlying data reflecting particular changes in the values that Garmin deliver - what's happened for my status to go in 4 days from a consistent window of Unproductive to a consistent window of Peaking, stopping off for a day each in Maintaining and Productive along the way? What specific things did I do in my training to get there, and how can I formalise that to get the best out of myself for whenever my next race finally is?

In order to be able to interpret the changes in any meaningful way there has to be consistency to the data that rises above the noise at the level of granularity you want to be at with 2 decimal places. That simply isn't going to be the case. Remember, as per Garmin, the VO2 max score you are seeing is the VO2 max/kg so your weight is also a factor in the calculation. Since the OP is weighing and updating his weight on a daily basis to the decimal point, there are too many variables changing to make any meaningful interpretation of the data. Now, if one would to only update one's weight monthly, and had a stable weight to run the daily trends against, perhaps then one could make an argument that the trends would be useful. Maybe. Even then, VO2 is less an indicator of true performance ability than lactate threshold. If you have two people with the same VO2 max, but one has a higher lactate threshold, that person will outperform the other despite having the same VO2 max. VO2 max gives an indication of potential performance, lactate threshold indicates what you are actually capable of doing. That's a trend that you should be tracking with a higher priority than VO2 max.

www.active.com/.../lactate-threshold-and-v02-max-explained

My Garmin only measures and reports VO2 Max once in a blue moon by rules that are totally obscure to me. So I do the math by taking the Ryan's high, let's say 165 and divide it by the resting heart rate, like 64, then multiply by 15.3. 

Fitbit gives daily VO2 Max, why Garmin can't do it is a frustrating mystery to mem

a run's high not Ryan. 

I believe a run has to get above 70% max HR for a period time to trigger a measurement.

Yep: https://support.garmin.com/en-GB/?faq=MyIZ05OMpu6wSl95UVUjp7

"

• In order to generate a Running VO2 Max estimate, you must record a Run activity with heart rate for a minimum of 10 minutes above 70% of your max heart rate. Walking in most cases will not provide you with a VO2 Max estimate. 

It follows that I should go to Settings and lower the heart rate they write there. The math of the VO2 Max will not be influenced, but the software will be tricked into triggering the computation. 

This is one thing I like the Fitbit better for, they give you the VO2 Max daily, whether you run or not