Anyone here who understands VO2max and it's pitfalls?

yirara

Ok, VO2max is an estimate of the total oxygen consumption during physical exertion. In a lab setting it's a number calculated somehow from ventilation and oxygen and carbon dioxide concentration of the inhaled and exhaled air.

If I understand this correctly, if there's one part of this not working properly, be it inhalation or exhalation due to lung problems, the heart not working properly, transport of oxygen into muscles or aerobic energy production then the VO2max should be lower, right? What I'm trying to understand is what the influence is on VO2max if two or three of these things work super well and above average because training for years and very fit, and one or two are limiting factors.

Does anyone know or even know some half easy to understand papers on this? Would it be possible to get on paper a half good VO2max based on a short lab test, without being able to make full use of it in everyday exercising?

AnnPT77

I hope someone has info for you, because I'd be interested in it. (I've been diagnosed with early COPD, still pretty much asymptomatic, but the other body functions seem to be working fine.) I wish I could help: All I know about VO2max is "higher is better in my sport". I periodically think about getting lab tested as a baseline, but haven't gotten around to it. 🙄 (The local university has a sports medicine lab that does this sort of thing.)

yirara

Oh no! But good it's still mild.

I also have a reason for trying to figure this out. Basically, the lab tests I had gave me a VO2max that is not super high but ok. All my running data over nearly 8 years is on Runalyze which somehow estimates VO2max. Their estimates are similar to the lab tests. So lets assume the VO2max is correct. They also predict race finish times for all the usual distances based on VO2max (and other methods that yield quite similar results). All race results they predict based on my VO2max are far too fast. Basically, they give me times and paces I've never ran in 8 years, not during races, not during fast running attempts. It's just not possible. Last night I found a nifty function: if your race predictions are different to actual race result then you can use a correction factor. This lowers or increases your VO2max estimate. So I do virtual races every now and then and have some numbers, and so I used this correction factor - and found I had to correct VO2max downward by 30%.

When I had those exercise tests the doctors told me I was fit. No problems. Using the corrected VO2max I would have failed the exercise test as it's quite a bit below the expected number. In VO2max tables for my age this would be in the "very poor"category. Basically someone who sits behind the telly all day. But I've been running for nearly 8 years. So something is off. And I'm trying to figure out whether there's something in VO2max that would explain this mismatch.

There are some equations that only take HR data into account. Not useful
Found an old definition in an exercise test where VO2 plateaus that's the VO2max. Ok, but that only takes inhaled oxygen into account and not what happens within the muscle.
The fick's equation Vo2max  =  (SVmax × HRmax) × (Cao2max − Cvo2max): you need arterial and venous oxygen content and stroke volume for this. Looks like this is what I need. But you seem to need blood tests for this. Thus also not useful. Argh.

Lietchi

I don't have real answers for you, but I also use Runalyze, and I have/had some surprising numbers too.

Currently it gives me a VO2max of 35 (Garmin gives me 45!). But that's after running a 5k race almost 2 months ago, which gave me a correction downwards. Before that, I think it was giving me around 39 as VO2max.
As for the race time time predictions, they were ridiculously fast before my actual race, and now less so but still optimistic.

Obviously, I don't have your health issues, but still some slightly odd numbers (and unfortunately no idea of my real VO2max). I wonder if the formulas used by Runalyze might just be off?

spiriteagle99

I only have a Garmin to give me VO2max numbers. Mine gives me a superior rating because my HR is usually quite high when I do my runs. It seems to assume that I am doing a lot of speedwork, which isn't the case. When I adjusted my maximum HR, closer to reality, it gave me lower numbers, but still superior. (At age 65, with a max of 185+ instead of 165, I dropped from 49 to 44.) The race predictor gives me a ridiculously fast time for 5k, a slightly slower than my actual PR for HM (but faster than my current time), and 34 minutes slower than my marathon PR.

yirara

Thanks a lot Lietchi. It's super encouraging that not only i get odd numbers. Might just be their algorithm then. I do trust their VO2max estimation kind of though. Garmin on the other hand is totally shite. Like with you it gives me about 10 more. I think the problem with Garmin is that it counts also very short runs and the warmup part of a run: HR is low then = yiha! super high VO2max while Runalyze excludes this part unless I change some settings. Mind you, the race time predictions of Garmin pretty much mirror those of Runalyze. Hmm..