How vo2 max relates to fitness

I understand the distinction, and if you start a thread on it, I'm pretty sure you will actually find I agree. But that's not the thread here, as I keep saying.

So what are you disagreeing with and why?

Running is a set of skills, so is cycling. But having a VO2 max of 75 ml/kg/min is irrelevant to how much skill you have for either.

Best bet is just to reply to the subject "How vo2 max relates to fitness" rather than sidetracking other older posts...as I do think you have some useful info, but it's just not coming across.

Everybody talk about Vo2max or critical power, or lactic threshold, but to me the more important factor in performance

for distance running is still BMI. And this is genetic , it depends from the skeleton , how wide is it at the shoulder at pelvi.

If I'm 1'75 height but have a bigger skeleton, When I m trained with a 8% body fat, my weight will be 69kg.My BMI is 22,53.

My critical power is 300 watt. And my watt/weight ratio is 4,3 W/kg.

Let's take another body type with a little skeleton , when you ll cover it with muscles and tendons you will have a smaller volume and a lighter body, so for the same weight we ll have 57kg. This second runner has the same critical power 300 watt

( and the same we can say for the VO2max) . So watt/ratio is 5,2 W/kg.

And these value gives differents times in races of course. So here we have two runners with almost identical criticl power

and Vo2max but their difference in BMI is what makes the second runner a lot faster than the first one when it comes to

distance running.

Of course sprint and partially 800 /1500 are a different thing.

A guy like Eliud Kipchoge is able to mantain in the marathon about 320 watt. His weight 52KG . Watt/weight is 6,15 W/KG

and gives a 2:01 / 2:02 marathon.

With same watt 320 but a different weight like 60kg . Watt/weight is 5,3 W/KG. Now Kipchoge with the same critical power would be around 2:20 in the marathon.

Well, losing weight (and hence lowering your BMI) improves your VO2 max, all else being equal. Its units are ml per min per kg.

It would be an interesting thread to relate all the things that people do thing have an impact and their significance. I note people often also forget simple effect of the mind & brain for example, but I guess this is just on vo2max ?

it's genetic wrote:

Odd...... wrote:

Well, yes, some people didn't improve, and most did.....what's your point ? The disagreement afaics is between those saying it's 'completely' genetic, and those who say it has a genetic foundation and can be improved by training (even if that's not the major factor). This supports the latter, and not the former.

I'm guessing the disagreement is actually one of semantics, and people not being precise enough in their statements previously, but I may be wrong.

It's not semantics. The problem is that VO2 max has to be properly tested. So it's more of a case of incorrect testing protocol, a cookie cutter testing method that doesn't take into account that if the person being tested is sweating profusely or is not producing enough adrenaline they won't reach VO2 max.

...

Part of disagreement here is semantics.

Some seem to think VO2max as an individual's genetically-constrained limit for maximal oxygen consumption.

As clarified before - that is NOT what VO2max is. (That would be more like "Max VO2max" )

VO2max is simply a measurement of oxygen consumption (oxygen transported vs.body mass over time) - AT A POINT IN TIME (the test).

Other seem to think truly sedentary people may naturally have a VO2max close to their potential limit.

They do not.

Take a couch potato, test their VO2max, and you you might get 35 ml/Kg/min.

Train them for distance running and six months later they may test 60.

VO2max is significantly trainable. Potential is not.

VO2max is an imperfect measurement meant to imperfectly reflect a thing, aerobic fitness, it is not the thing itself.

Consider - body composition varies across people/runners - the same running performance can be achieved with widely differing body types.

Someone with a low VO2max might run just as fast as someone with a much higher VO2max, all other things being equal.

It is a mistake to strongly correlate VO2max to running performance. They are linked, but generally.

Consider - changing an individual's mass changes VO2max (its relative to mass). So losing mass not efficiently contributing to fast running (fat, extra muscle mass, excess glycogen, water, body waste, etc.) changes VO2max - with no real change in aerobic fitness its intended to reflect.

VO2max is only one metric for indicating ability for fast, sustained running.

Part of the confusion may come from Jack Daniels and others who refer to "VO2max workouts", thinking they are training your limit, or even training aerobic fitness. It's a misleading term and meant to describe degree of effort.

No analogy is perfect, but you can think of a runner's body like a race car - its a system of countless things coming together to define performance. VO2max might be like fuel efficiency or engine HP, but with changes and tuning, you can improve those. And aside from the engine, there are many other factors determining speed; driver skill, tires, transmission, wind resistance, vehicle weight, conditions, etc.

All of this is correct. Good post.

And to the one saying cardiac output never changes - wrong. Cardiac output is simply stroke volume * heart rate. Max heart rate doesn't go up with training (in fact it may go down slightly), but stroke volume increases dramatically. The heart gets bigger, works better and the higher blood volume also makes it possible to pump more blood with each beat. I'd like to see the studies you are talking about that cardiac output doesn't change in humans, that's nonsense.

it's genetic is either a troll, or defining words in a unique way.

1. "it's genetic" is meaningless. Every phenotype is the result of a unique combination of a genotype + some non-genetic factors in the egg cytoplasm + plus some epigenetic factors growing up in a unique environment, where the environment is everything experienced from conception to the present (egg and sperm environment are included in the epigenetic component). There is no "environment-less" environment. There is no phenotype that is invariant across every possible environment.

2. it's genetic may be defining VdotO2max to mean the maximum potential VdotO2max across all possible environments (an essentially infinite set). If this is what he means, it is irrelevant. No one experiences this environment.

3. it's genetic may be defining VdotO2max to mean the maximum measurable VdotO2max at some point in a person's history. If it's genetic thinks this measure is constant across all possible environments, then he is wrong. Or I'm wrong, but it would take incredible evidence to convince me and so far, it's genetic has offered zero (and I could care less about his history).

I'm saying that cardiorespiratory health and functionality is something that is maintained rather than trained. And that much of the literature on the subject gives misinformation leading to false assumptions, and unrealistic projections of supposed increases in oxygen delivery. If you read a lot of the literature you will see many conflicting ideas.

Yes couch potatoes losing a lot of weight will get a much higher score in the weight relative mesurement, that's why I used the absolute measurment as an example as you will see in one of my rants to a certain other poster who wants neat defintions. So I asked him if he thought all the training I did 'improved my VO2 max?' The answer is no because my oxygen delivery was perfectly functional at a young age and there was nowere for it to 'improve'. But I did greatly improve my race performances over many years. The training effects are misrepresented by a mythology of supposed improvements in oxygen delivery.

If your cardiorespiratory health is excellent, and your maximal oxygen uptake for 1 minute (as per JD's minute volume measurements) has been properly measured (how would you be sure you were really at your max?) it is unrealistic to expect any improvement in that function. But it is realistic for Joe Couch Potato to greatly increase his running fitness through improved endurance, and one of the improvements may well involve an increase in stroke volume.

Really we should be discussing the variables of which there are very many before dumbing this issue down into palatable bytes for mass consumption. Or better still find a good coach when you're young and thereby avoid all the red herrings proffered by ex phys geeks.

LateRunnerPhil wrote:

And to the one saying cardiac output never changes - wrong. Cardiac output is simply stroke volume * heart rate. Max heart rate doesn't go up with training (in fact it may go down slightly), but stroke volume increases dramatically. The heart gets bigger, works better and the higher blood volume also makes it possible to pump more blood with each beat. I'd like to see the studies you are talking about that cardiac output doesn't change in humans, that's nonsense.

It's not nonsense. Cardiac output is maintained for cardiac health. But if you read through the literature you are going to find a mass of contradictions.

When you read about a XC Skier with a Cardiac Output of 40 liters/minute, he didn't train for years to get that, it's genetic, he's a big endurance athlete with a naturally large heart and a high absolute V02 max well over 6 liters/minute.

So a 180 pound endurance athlete may well have a 50% higher Cardiac Output and VO2 max than a 120 pound guy. And that's not even taking oxygen economy into account.

But in much of the literature you will find this dumbed down to stupid level where many authors write about how some endurance athletes have "increased their Cardiac Output, to over 40 liters per minute"

Nope, it's genetic. They had that CO when they were in their late teens before they started training.

Go on take a look, you'll see the same stupidity repeated over and over in the literature.

But you cant lose weight beyond a certain limit. Thats why I say that body type is genetic. BMI 18-20 (distance runners)

21-23 (800- 1500) 24- 26 (sprinters).

Here we talk about people that are trained with low body fat and running muscles ( not body builder)

Usain Bolt has a 25 BMI not matter how he tried he will never be a marathoner with a 18/19 BMI (is just not his genetic)

execept he will lose a lot of muscles but then no power again.

So losing weight is a nonsense you cant go beyond your genetic limit , that's when you ll have about 5% body fat.

You cant go lower and at that limit your body weight will tell you as BMI how good you can be for distance running.

If you have a very big total Vo2 max but your bmi is 24/25, no way you ll be at the top as a distance runners.

Ok, here are the reasons why Cardiac Output / VO2MAX increase in endurance athletes:

1) More stroke volume (30-50% more). Each time your heart beats, you will pump more blood. This is due to increase in recoil capacity, so when the heart stretches and closes when it pumps it pumps much more.

In numbers: Sedentary, untrained people only pump 100 ml of blood per beat, trained athletes pump 150 ml, with world-class athletes above 200 ml. That's a huge difference!

2) Higher blood volume. You can get 15% or more blood volume with endurance training. Red blood cells can increase by 10% - yes, this means a sedentary person will have higher Hemoglobin/Hematocrit values due to their abnormal low amount of blood volume. Since it's a ratio, it suggests they are world-class athletes but in reality they are just really unfit. I had 16.7 HB and 49% HC when sedentary which is around the levels for blood doping, and couldn't even run one mile without stopping.

With training, my RBC count increased, but my blood volume increased even more in relation causing HB and HC to drop.

3) Number of capillaries surrounding muscle fibers increase. Barrel size increases too, which increases blood flow!

4) Aerobic enzymes within mitochondria increase - better oxygen transport.

5) Density of MTC1 and MCT4 increases, increasing transport of glycogen to muscle fibers and removal of lactate/H+ out of them.

There are more reasons, but that should be enough. Do I believe VO2MAX is important? No, not the absolute value. But certainly the speed. Kastor was measured at 81-82 which is insane for a female, yet she was slower than Radcliffe who peaked at 70. Daniels tested 3 females with the same VO2MAX and one ran 8:45, one 8:58 and one 9:13 in the same race. What matters is not the absolute value, but the velocity someone can achieve at VO2MAX (which can be held for around 6-7 minutes).

To increase VO2MAX and the velocity at it you need to train/race at 2k-10k pace (unless you are a complete beginner where just running is enough). Ever wondered why some people, who train the same steady or moderate pace day in and day out don't get faster? Cos it's not enough stimulus to improve VO2MAX.

Thanks. I was too lazy to dig that up.

I worked alongside cardiologists in a world-class medical school for over 10 y. None of them really knew anything about exercise physiology, just as I don't really know anything about, say, congenital heart disease.

One of but dozens, if not hundreds, of studies directly demonstrating an increase in stroke volume, and hence maximal cardiac output, in response to endurance exercise training:

https://www.ncbi.nlm.nih.gov/m/pubmed/1385806/

Finally, as for the "it's all genetics" argument, what the science actually show is that genetic inheritance only accounts for 22-57% of baseline VO2max. (Trainability of VO2 max is a different question, but it, too, is only about 50% genetically determined.)

https://www.ncbi.nlm.nih.gov/pubmed/28074345

it's genetic wrote:

LateRunnerPhil. You need to do a lot more research.

Cardiac output is genetic, it doesn't increase with training despite what you may read on wikipedia.

In a young person the stroke volume is lower, but the heart rate higher at all intensities and the reverse is true for an older person. This maintians cardiac output and a healthy heart.

The higher heart rate/lower stroke volume of a young person naturally gives them a higher oxygen uptake. Your research will reveal much conflicting information on the subject.

But please be aware that there are researchers whose job it is to save peoples' lives who may be much better informed on cardiology and hematology than the average exercise physiologist and so there is good and bad information available on the subject of oxygen uptake and delivery.

No doubt Q (cardiac output) has a genetic link, but endurance training increases blood volume both in terms of red cell mass and plasma volume. If blood volume increases then Q increases. There are good studies from Claude Bouchard showing the hereditary component of VO2max. Also the trainability has a hereditary component.

A note: Vo2max is the product of cardiac output and a-vO2 difference. Cardiac output is heart rate X stroke volume. The latter being the amount of blood pumped with each beat. A-vO2 difference is how much oxygen can be extracted from the blood--red cells specifically. More O2 can be extracted in a trained person in part because there are more red cells in a trained person (on avg), because of an increase in capillaries in the trained muscles and an increase in mitochondria in those trained muscles.