Re-setting VO2 Max

I don't think there's a way to reset the VO2 max because it calculates automatically.
The only way I see to completely wipe it out is to do a restore defaults and start fresh.
But that would mean to reconfigure your preferences.

Maybe you can take a copy of the fit files from the sports folder before restoring the defaults and put them back later (after the restore defaults).

Re-setting Totals didn't have any effect, so that can be ruled out.

It's not worth doing a hard reset.

I do think however it should be an option to be able to reset V02 Max and Race Predictor so that these numbers can more closely approximate 1) current level of fitness and 2) terrain-specific (road, trails, hills, treadmill) training.

Reset totals won't touch the vo2max.
It's not really a hard reset. It's the restore defaults (which is a soft reset).

AFAIK the VO2 max is automatically calculated whenever you're wearing the heart rate strap.
So, if you run on the trails, in the end the result should affect your current level of fitness.
If you run the next day on the road, that would be adjusted accordingly as well.

So, I don't really understand what do you mean by being able to reset the vo2max if it's always being recalculated (provided you're wearing the heart rate strap and do a long enough activity).

Firstbeat has a good white paper on how the algorithm for VO2 Max works. In essence, it tracks HR and running speed, and compares these data against comparable numbers from a database of people that had these measured metrics AND laboratory-measured V02 Max.

The watch V02 Max 'learns' over time and therefore some of my current V02 Max comes from metrics as old as my watch I guess. Not a problem now but will be in a few months. In a training cycle, V02 Max could be tested every few weeks to assess progress. I don't want data from 6 months ago to go into that calculation.

Also, if I train on trails and hills regularly, my HR and pace will be different than when I am training on roads in preparation for a marathon 8-12 weeks away. My understanding of the Firstbeat database is that runners were doing 6-9 month preparation for a marathon, presumably (assumption on my part) on the road.

What I'd like to do is reset the V02 Max and Race Predictor at the beginning of road marathon training cycle to a) have a more current measurement not affected by months of previous measurements and b) have a more accurate V02 Max number that reflects the different type of training terrain (ie from trails to roads).

Got it!
I guess for now, the only option would be the restore defaults. And I don't think there's any other option in the line of current watches (either forerunner or outdoor division) that would allow to "reset" the vo2 max calculation.
That would be a great idea to send to Garmin through their idea page.
Who knows they would take that into consideration?

You can just do restore defaults in settings, system to clear VO2 Max and start over. My experience is that the algorithm fairly quickly reacts to changes anyway. What you did 6 months ago certainly won't matter.