Okay, so I know VO2 max calculation is a recurrent debate, and there are countless threads about it since Garmin and Firstbeat don’t give much details about how their algorithm really works. All we know (knew) is that it compares HR and pace data, and estimates the level of effort based on max HR percentage. But I feel there might be more to this. For the best, or worst.
What I am worried about is that in the beginning of summer 2022, Garmin made some changes in their algorithm. Before that, the VO2max was calculated after each activity. Plain and simple. Since that update, VO2max is now synced with Garmin Connect and saved into your profile, along with training status and some other information such as HRV, training load, etc. Good thing is that you can reset your watch, sync, and data will be there, just where you left it. But here’s my point : it looks like VO2max is now “weighed” by the previous recorded value, and as I suspect, other data (HRV?) which may lock or unlock quick VO2max change.
If you look at the table above, you’ll see my reported VO2max values after each run. What is clear is that since mid 2022, the value changes very little between two runs, and so it can take up to months of training to see a significant (+1) change in VO2max reported value.
That brings up two questions :
- Is this the wanted behaviour ? Since the VO2max reflects physiological changes, which are slow by definition, it could make sense that important VO2max change is “filtered” by the software.
- If yes is the right answer to question 1, then has Training Status – which is mostly based on how quick VO2max rises or fades – become completely irrelevant ? I think so. because based on my personal experience, VO2max changes and training status have always been pretty much in line with how strong or fit I felt. This year, it happened quite often that I got “Maintaining” TS, whether I was improving PRs and training hard & consistent, or being sick and feeling like sh**. If you look at the last 3 months my VO2max is slowly decreasing, while my training load is getting higher and race prediction time is improving.
- Would there be a way to "reset" the value and start up with a fresh, new measurement that does not account for activity history ?
I would be interested to know if other users have noticed the same change in the VO2max calculation process. Not that it would be a life changer of course, but if VO2max is no longer a good indicator to follow, it’s better to be aware of it.
Also, it would be great if we could have someone from Garmin ( @Garmin_Chris ?) give at least some background information... VO2max changes were never mentioned in any backlog.
Thank you for reading this far !
