VO2 Max and FTP comparisons

optical measurement is not very good at measuring HRV I believe. So I wonder if a more accurate estimate of VO2 max will be achieved when using a chest strap?

Without reference VO[sub]2[/sub]max figures obtained from lab tests, against which to compare what a consumer fitness tracking device reports as an estimate, there is scant valid basis on which to conclude whether the estimate is accurate anyway. Yes, of course somebody can cite statistics produced by studies performed on a significant number of test subjects whose VO[sub]2[/sub]max figures are both measured and estimated, to give some indication of the confidence level one could have in the estimation tools (or method) he prefers to use and/or is trying to sell, but that wouldn't tell me anything about the accuracy of an estimate thus produced for my VO[sub]2[/sub]max.

For what it's worth, I moved from an FR235, using its optical HRM exclusively for the final nine months, to a FR630, with which I use the HRM4-Run chest strap. The two Forerunner models effectively share the same firmware, so I'll assume the VO[sub]2[/sub]max estimation method is identical in both devices, and that changing devices did not in itself have any impact on my fitness and my training habits. My VO[sub]2[/sub]max as reported by the devices went from 47±1 observed over the three weeks prior to the transition, to 46±1 observed over three weeks after the transition. So, yes, the use of a chest strap HRM made a difference, but not a very significant one.

The general consensus on here appears to be that Garmin devices significantly overestimate VO[sub]2[/sub]max, so on that premise the estimates produced when I was using a chest strap HRM would be truer.

Steve - max HR is very individual. If you are hitting those numbers regularly they must be right for you. I could hit high 180s but over 20 years ago!

Sounds like 46 or 47 with and without chest HR suggests no significant statistical difference and that's without really delving into how you were doing in those runs. So that's good then...

This thread had me thinking about the unreasonable VO2Max numbers that I normally get from my Garmin devices. While I was considering lowering my HRMax to see if that would bring the number more in line with my actual performances in the Race Predictor I wondered how that would effect my HR zones and TE numbers.

Currently my F3 has me at 54 which gives wildly optimistic race predictions, but my 235 (which recently reset itself for some reason) has me at 49 which puts the race predictor within seconds of what I ran on Saturday in a 5k and the 10k and HM are very reasonable numbers.

So I lowered my HRMax from 180 to 171 (I peaked at 170 in the 5k this past weekend which was a PR but wasn't all out) and the HR zones became way too low for where I normally am on regular runs when using % of HRMax. But found that the zones were perfect when I changed it to % of LTHR that I got a couple of months ago.

I haven't done a run since making that change so I still don't know how it will effect my TE scores but we'll see over the next couple of days.

Strange that you should get different VO2Max values if the HRMax is the same on both watches (I assume you use a different account for each watch?). That's what I did for the FR235 (not reset for 12+ months) and the F5 (3 weeks old) and they're showing identical VO2Max (same as in runalyze in fact).

I was also worried about messing up the zones but in GC (watch settings) you can keep those of your "real" HRMax and put your "current fit HRMax" in the "HR Max" field.

That's one common problem with VO2 Max algorithm - if you can't get to the range 171-180 then the algorithm will think you have more to give and give a higher value than it should be.

Any changes here will tend to take a good week to settle down again.

Strange that you should get different VO2Max values if the HRMax is the same on both watches (I assume you use a different account for each watch?). That's what I did for the FR235 (not reset for 12+ months) and the F5 (3 weeks old) and they're showing identical VO2Max (same as in runalyze in fact).

I was also worried about messing up the zones but in GC (watch settings) you can keep those of your "real" HRMax and put your "current fit HRMax" in the "HR Max" field.

Both watches are on the same account. It's just that I've only done a couple of runs with the 235 since it randomly reset itself so it's still relearning me.

After a while they'll be back in sync with each other as they've been in the past. Right now though every time I run outside with a different one it resets the VO2Max in GC which is kinda annoying.

I submitted this as an improvement to a Garmin Tech the other day he said that he has submitted it as well, it makes sense that my 935 and fenix 5x should true-up all the data not just steps, but maybe I am missing something.

Both watches are on the same account. It's just that I've only done a couple of runs with the 235 since it randomly reset itself so it's still relearning me.

After a while they'll be back in sync with each other as they've been in the past. Right now though every time I run outside with a different one it resets the VO2Max in GC which is kinda annoying.

BTW, when I receive my new 935 I plan on creating a brand new Garmin Connect account as the existing one is already messed up by poorly adjusted pace plot ranges (that cannot be adjusted by the user) and because I have no clue how the array of watches on my old account (FR10, 235, 630, 735) will affect what gets transferred on the 935.

This thread had me thinking about the unreasonable VO2Max numbers that I normally get from my Garmin devices. While I was considering lowering my HRMax to see if that would bring the number more in line with my actual performances in the Race Predictor I wondered how that would effect my HR zones and TE numbers.

Currently my F3 has me at 54 which gives wildly optimistic race predictions, but my 235 (which recently reset itself for some reason) has me at 49 which puts the race predictor within seconds of what I ran on Saturday in a 5k and the 10k and HM are very reasonable numbers.

So I lowered my HRMax from 180 to 171 (I peaked at 170 in the 5k this past weekend which was a PR but wasn't all out) and the HR zones became way too low for where I normally am on regular runs when using % of HRMax. But found that the zones were perfect when I changed it to % of LTHR that I got a couple of months ago.

I haven't done a run since making that change so I still don't know how it will effect my TE scores but we'll see over the next couple of days.

But isn't it kinda crazy that we consider tweaking our MaxHR, zones etc. so that we can feel that our estimated VO2max values are more realistic? We are talking about a $500+tax brand new watch which main claim for existence is that it can estimate, record and update our fitness metrics. I understand that no algo is ever perfect but I do strongly believe that Garmin/FirstBeat needs to provide more clarity for their estimation methods so that we know what to expect.