Optical HR *does* create VO2 Max estimates?

With any biometric measured that's estimated rather than, well, measured it needs to be taken with a grain of salt. How well the optical HRM generated Vo2Max compares to one generated from chest strap measured one will depend whether or not HRV comes into play or not.

So as long as you just look at it in isolation and just compare measurements taken from the same device in the same way you can still see how you might be progressing.

Ok, my VO2 max on my year old 920xt goes between 45-47. Take a look on GC for folks over 70 with those VO2 numbers. Now 3 runs with my 235. VO2 max has moved from 41 after my first run to 43 after my third run(25.5 miles total). So something is going on, i.e., it appears to be getting some kind of reading. Also all my runs have been around 2.8 to3.2 training effect, getting lazy as I get older.
Back in my 40's I ran17:xx 5K's/36:xx 10K,s and never had a clue what my VO2 max was, worse than that, I didn't care. Not sure how I ran those times, especially smoking 1-2 packs of cigarettes a day into my early 30's before I quit and got serious about being a fit soldier. Did that w/o knowing HR/cadence/vertical whatever/ ground contact time, and the all powerful metric of actual pace. Had I had all those metrics back then, who knows how much faster I could have run.

Not really surprising that these numbers would be computed as you could already get VO2Max/Recovery/TE readings from an FR620/930/F3 using a Mio or Scosche strap as HRV info is required in the ANT data stream. It's just that HRV numbers were "estimated" so you're adding additional uncertainty to what is already an estimate...

It's possible Garmin are just following that route (i.e. Elevate not more accurate in terms of HRV than Mio or Scosche) with the FR235 and the fact that RUNN is getting different numbers than with his FR920 seems to indicate that, but more feedback is necessary of course.

DC Rainmaker has repeatedly said that Garmin's new Elevate Optical HR in the Garmin FR 235 will not create VO2 Max estimates which require a conventional chest strap.
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So I was very surprised that after my very first run with the 235 using the optical sensor it generated a VO2 Max score. Any ideas if this means Garmin thinks it is accurate or should I ignore it since it wasn't generated with a chest strap?
Thanks...

He updated his comments to say that it will. (note underlined and italics section)

We see some of the advanced features previously only seen on the FR620, moving their way down to the FR230/235. For example, VO2Max values are now found on the FR230/235. Note that for the VO2Max tests though you do need to have a traditional heart rate strap paired to the FR235, since that’s not capable of leveraging the optical sensor for that test (common due to lack of accurate heart rate variability on optical sensors). Update: It looks like they are enabling this with native optical sensor.

I made a comment about it on Oct 29th. http://www.dcrainmaker.com/2015/10/garmin-fr230-fr235-fr630.html/comment-page-1#comment-1356755

Good way to see if the VO2 Max is in the ballpark is to see what Race Predictions it gives as these are directly linked.

Typically I have always found on devices that have VO2 Max is that it starts at a lowish value and creeps up a bit over the next week or so before levelling out.

Good way to see if the VO2 Max is in the ballpark is to see what Race Predictions it gives as these are directly linked.

Typically I have always found on devices that have VO2 Max is that it starts at a lowish value and creeps up a bit over the next week or so before levelling out.

That has been my experience. Still at 43 for me after my fourth run-8.2 mi @3.2 training effect.