Other/Mixed Article: The Fallacy of VO2Max

[Steve Freides]

I've lately read conflicting theories about VO2-Max and it's application to endurance training, so I did web searches Googles:

Google #1: Is measuring VO2Max useful?

and

Google #2: Is measuring VO2Max useless?

I found this article from my second search to make interesting reading:

The Fallacy of Vo2max and %VO2max – Science of Running

-S-

 

[offwidth]

I've lately read conflicting theories about VO2-Max and it's application to endurance training, so I did web searches Googles:

Google #1: Is measuring VO2Max useful?

and

Google #2: Is measuring VO2Max useless?

I found this article from my second search to make interesting reading:

The Fallacy of Vo2max and %VO2max – Science of Running

-S-

Training For the New Alpinism
Steve House|Scott Johnston
2014
ISBN 978-1-938340-23-9
Pages 102-103 "The V02 Max Myth'

If there is one activity that exemplifies extremely high cardio-respiratory and muscular fitness it is Alpinism as it is practiced by the cutting edge climber-athletes of this generation. Mr. House has been at the vanguard of this elite class for years.

Dan John has mentioned that "success leaves tracks"

 

[Steve Freides]

Yes, my reading is that VO2Max isn't all is was previously thought to be or, perhaps more accurately, improving one's VO2Max measurement isn't necessarily going to be a good predictor of improved performance at any athletic activity.

I don't understand the science behind all these discussions, but I do find them interesting reading.

-S-

 

[mprevost]

This discussion has been around for a couple of decades now. There are lots of holes in the classic concept of VO2 max. VO2 max is not the best predictor of performance but having a big VO2 max is seen more as a "ticket to the show." Without a big VO2 max, you will not be able to play with the big boys and girls but the biggest VO2 max does not always win. In fact, the data below is from Paula Radcliffe, world record in the marathon.

You can see that here VO2 max did not really improve from 1992-2003. However she ran MUCH faster in 2003. The graph below is a graph of her running speed at VO2 max. You can see that she got faster and faster at VO2 max.

This is what is referred to as improved run economy. She used less oxygen at every given speed, including VO2 max. This is what accounted for her improved run performance, even though her VO2 max did not improve. This is a common occurrence in mature runners. Lots of volume of zone 2 running can lead to dramatically improved run economy over time, improving performance even if VO2 max is not improving.

You can measure run economy at the same time as VO2 max during a test. I always do, along with ventilatory threshold or onset of blood lactate accumulation. You need more than VO2 max to tell the story.

 

[wespom9]

@mprevost By "run economy", do you refer to the y-axis on your chart?

 

[mprevost]

@mprevost By "run economy", do you refer to the y-axis on your chart?

Run economy is not depicted on either chart. It can be inferred by taking the info from both charts together. Run economy is typically defined as ml of oxygen per kilogram of bodyweight per kilometer. A simpler way to think about it is how much oxygen it takes to go a specific speed. It is sort of like a gas mileage figure for a car but in this case it is oxygen instead of gas.

 

[mprevost]

I've lately read conflicting theories about VO2-Max and it's application to endurance training, so I did web searches Googles:

Google #1: Is measuring VO2Max useful?

and

Google #2: Is measuring VO2Max useless?

I found this article from my second search to make interesting reading:

The Fallacy of Vo2max and %VO2max – Science of Running

-S-

Here is a simpler way of looking at the whole thing. If we use an analogy of a car, we can simplify. Let's simplify the drivetrain of a car into the fuel pump & pipes, and the engine. The corresponding parts in the body would be:

Fuel pump & Pipes = heart and circulatory system
Engine = muscles (and mitochondria)
Gas = oxygen
maximum gas burning rate = VO2 max

The argument in this article has to do with what limits VO2 max. The traditional view is that it is limited by the pump. It would be like having a car that could go faster but the fuel pump cannot supply gas fast enough to push the engine to its max capacity.

The real issue is that if you are a race car driver, you don't care if you can tweak your car to burn more gas. You just want to go faster. A higher gas burn rate generally means that you go faster. You would be burning gas at a faster rate at 60 mph than at 10 mph for example. However, your buddy might be able to go faster than you at 25 miles per gallon. You are both at the same fuel burn rate but he is faster. This is basically what happened to Paula in the data I presented. Her "engine" became more efficient. She improved her MPG so that she could go faster at any specific MPG. It would be like a car that can burn fuel at a max rate of 25 miles per gallon and that results in 100 miles per hour. If we make some aerodynamic changes and tweak the engine so it burns more efficiently, maybe that 25 miles per gallon will now get us to 110 miles per hour.

So, for our car analogy, who cares about increasing your fuel burn rate if you are a race car driver? It is a poor way to estimate speed. Speed is what we are after. Same with VO2 max but with VO2 max the fuel is oxygen. Better economy = faster on less oxygen.

Hope that makes sense. It does in my head anyway.

 

[ali]

@mprevost.....ah, if you may help with this query.....

In a VO2 test though are you not measuring anaerobic input too?
If working at max, whilst there is max oxygen utilisation the anaerobic system is kicking in too. Could you not argue then, that to increase VO2 max, you could increase oxygen utilisation and/or be more efficient at utilising glucose anaerobically by more efficient enzymatic processes within the cell and a more efficient systemic re-uptake of lactate, either directly in cardiac muscle or indirectly hepatically by converting lactate back to glucose?
So whilst someone may have excellent oxygen utilisation trying to increase output....what appears to be a gain in VO2 max.....could also be due to an efficient use of lactate. Or is this not the case? If you could shed light onto this it will save me from my restless soul. Many thanks.

 

[mprevost]

@mprevost.....ah, if you may help with this query.....

In a VO2 test though are you not measuring anaerobic input too?
If working at max, whilst there is max oxygen utilisation the anaerobic system is kicking in too. Could you not argue then, that to increase VO2 max, you could increase oxygen utilisation and/or be more efficient at utilising glucose anaerobically by more efficient enzymatic processes within the cell and a more efficient systemic re-uptake of lactate, either directly in cardiac muscle or indirectly hepatically by converting lactate back to glucose?
So whilst someone may have excellent oxygen utilisation trying to increase output....what appears to be a gain in VO2 max.....could also be due to an efficient use of lactate. Or is this not the case? If you could shed light onto this it will save me from my restless soul. Many thanks.

No, not really. When you are testing VO2 max, you are measuring directly oxygen consumption (using a flow meter and oxygen sensor), so you are measuring only aerobic metabolism. In regards to lactate, increased aerobic fitness generally results in less lactate production and more lactate removal (mainly by slow twitch muscles) at any given power output. The gains we see in run economy are primarily due to improved run biomechanics and stiffer tendons, muscles (leading to more elastic energy return).

 

[ali]

@mprevost .....thanks. I get that if you are testing in a lab setting. I understand how improved running mechanics will impact too.
What about vo2 max predictors, bleep tests/1.5 mile runs etc? That to run a certain time predicts a vo2 max.....are those tests just measuring the ability to do those tests? So the only way to measure vo2 max is in a lab.....predictors are just that, a somewhat maybe guess?

 

[Al Ciampa]

FYI @Steve Freides ... what if the main governor was O2 delivery from blood?

 

[Steve Freides]

@aciampa, a very good question, indeed.

The whole equation becomes different if actual oxygen supply becomes an issue, but I don't know where that happens along the exercise/HR continuum. We know, e.g., that we can learn to improve O2 delivery from blood at rest, and even at walking pace. My guess is that improving it through Buteyko (or other Bohr-effect-related practice) will have carryover to athletic activity.

I will check with some of my colleagues and report back on what they have to say in a day or two.

-S-

 

[Al Ciampa]

I can only submit my personal experience.

Also, unrelated, I'm 2 hours back from you for the rest of the weekend.

 

[mprevost]

@mprevost .....thanks. I get that if you are testing in a lab setting. I understand how improved running mechanics will impact too.
What about vo2 max predictors, bleep tests/1.5 mile runs etc? That to run a certain time predicts a vo2 max.....are those tests just measuring the ability to do those tests? So the only way to measure vo2 max is in a lab.....predictors are just that, a somewhat maybe guess?

Yes, those tests correlate with VO2 max but do not measure it. As you stated earlier, those tests also involve contribution from anaerobic metabolism, so improved anaerobic fitness can improve performance on those tests.

 

[mprevost]

FYI @Steve Freides ... what if the main governor was O2 delivery from blood?

There is data to show that if you can deliver more oxygen to working muscle, you can improve oxygen consumption, indicating that O2 deliver may be a limiter. In this case the issue is generally either capillary density or mitochondrial density, so delivery and extraction respectively. Not all of the oxygen delivered to the muscles gets extracted. We measure this by measuring what we call the A-V O2 difference (difference in oxygen concentration in arterial vs venous blood). Greater mitochondrial density and more muscle myoglobin will create a greater concentration gradient and more oxygen offloading.

 

[Al Ciampa]

There is data to show that if you can deliver more oxygen to working muscle, you can improve oxygen consumption, indicating that O2 deliver may be a limiter. In this case the issue is generally either capillary density or mitochondrial density, so delivery and extraction respectively. Not all of the oxygen delivered to the muscles gets extracted. We measure this by measuring what we call the A-V O2 difference (difference in oxygen concentration in arterial vs venous blood). Greater mitochondrial density and more muscle myoglobin will create a greater concentration gradient and more oxygen offloading.

Thanks for taking the time to respond, Mike. I am familar with the content of your post. However, I was referring to the Bohr's effect and our shared breathing practice.

Thoughts?

 

[mprevost]

If you could make more oxygen available at the tissues, you could increase VO2 max a little. For example, breathing 100% oxygen can offer a small boost in VO2 max by increasing hemoglobin saturation just a little plus adding some dissolved oxygen but the increase is small since hemoglobin is typically 98% saturated even at VO2 max for most people (although elite endurance athletes may desaturase a little due to rapid blood flow through the lungs = less loading time). I can't imagine a breathing technique that would increase oxygen loading (except breathing 100% oxygen) or increase oxygen offloading without sacrificing oxygen loading.

For those who are wondering what the heck we are talking about. The Bohr shift is illustrated below. Basically oxygen is carried on the hemoglobin molecule in your blood. Hemoglobin holds on to oxygen tightly and is reluctant to let it go. However, in the tissues where oxygen is being used, CO2, hydrogen ions, increased temperature etc...reduce the affinity of hemoglobin for oxygen and it tends to let some oxygen go. This is called a Bohr shift. That way hemoglobin has a high affinity for oxygen when it is onloading in the lungs and a lower affinity for oxygen when it is offloading in the tissues (i.e., muscle). Cool huh?

 

[ali]

@mprevost ......thanks for answering my questions. It's a murky old world that cardio vascular system!

 

[mprevost]

@mprevost ......thanks for answering my questions. It's a murky old world that cardio vascular system!

Yes it is for sure. However, the training part is actually fairly simple and straightforward. All we need to do is apply progressive overload, and specificity and consider timeframes of adaptation.

 

[Steve W.]

FYI @Steve Freides ... what if the main governor was O2 delivery from blood?

I was referring to the Bohr's effect and our shared breathing practice.

Buteyko Breathing Technique – Nothing to Hyperventilate About

I've posted this before and I know @Steve Freides has seen it. While the linked article is critical in tone and much of its content, it does acknowledge that Buteyko breathing techniques have been shown to result in fewer reported asthma symptoms and less need for asthma medications, while also pointing out that they did not result in improvement in pulmonary function tests.

I am not trying be that guy who poo-poos Buteyko every time it comes up.

As someone who has been diagnosed as both having and not having asthma (at different times, by different doctors, using different assessments) I've actually practiced related breathing techniques as taught by Scott Sonnon, and the straw breathing taught by Pavel, and found them beneficial. Not being a pulmonologist and not having specifically practiced Buteyko breathing methods, I don't feel prepared to authoritatively comment on them.

However, I think the effects are likely much more limited than Buteyko advocates often claim (to be fair, the claims on the website of the Buteyko organization Steve F represents are more modest and qualified than those of some other Buteyko-branded organizations and proponents) and I suspect due to a different mechanism.