vo2 max calculator illogical results

[hjs]

Shifting of the anaerobic limit is best trainable, vo2 max less so, training lets us a higher % if that max.

[tsourbier]

When we look at the formula we see that it can be broken into 6 differents parts :

trained men > 75 kg
trained men <= 75 kg
untrained men

trained women > 61,36 kg
trained women <= 61,36 kg
untrained women

We can see from the formulas that the relationship between 2K time and VO2 max is linear.

for example :

For a 80 kg male we have :

trained => VO2 max = 1000 / 80 * (15,7 - (1,5 x (time in minutes))
untrained => VO2 max = 1000 / 80 * (10,7 - (0,9 x (time in minutes))

For a 50 kg female we have :

trained => VO2 max = 1000 / 80 * (15,7 - (1,5 x (time in minutes))
untrained => VO2 max = 1000 / 80 * (10,7 - (0,9 x (time in minutes))

this leads to the following graphs :




I can only suspect Dr. Fredrick "Fritz" Hagerman clearly separated the data from the various groups and ran a linear regression on each. As JerekKruger pointed out the data set may not have overlapped than much (too few fast - high VO2 max untrained subject or slow low V02 Max trained subject) this lead to unrealistic extrapolation. There are no reason that training shall make you slower nor that world record could be broken with just raw talent.

We should also question the linearity of the relationship. VO2 max is an expression of the quantity of oxygen one is able to consume to produce aerobic power. The "problem" is that the power and speed on the erg is not a linear relationship it is exponential!

It takes 104 watts to go 2:30/500, add 100 watts you'll go 2:00/500, add another 100watts you'll go 1:45/500 (you gained only 15 seconds this time), add another 100 watts, you'll go 1:35/500 ...



The faster the 2k time the less relevant the formula may become... Since trained athlete are surely faster on average than untrained one, I would have expected their line to be steeper than the untrained one based on the fact it requires much more energy to go from 6:30 to 6:00 on the 2k than to go from 8:00 to 7:30... but that's the contrary That's probably when the others factors in a 2k performance such as lactate threshold, rowing efficiency, etc... come into play.

[JerekKruger]

What makes you think VO2max is relatively poorly trainable? For one thing, it's determined by measurement during incremental exercise. The better you are at the test protocol, the more closely your results will approach their limits.

As I understand it, the actual VO2 max value is determined by measuring the oxygen and carbon dioxide concentrations of the air you breathe in and out. How far or how fast you get in the test isn't the important thing, only that you go sufficiently fast to achieve maximal oxygen consumption.

There are, I assume, other factors that would allow improved performance in the test other than VO2 max, so improved performance alone wouldn't indicate improved VO2 max. I might be wrong though.

Moreover, all of the major studies of the effects of training on VO2max I'm aware of show very wide variation in response to a given set of exercises. For an overview of the implications see http://www.trainingscience.net/?page_id=274

I suspect this is the study that I had seen reference to in the past, but something occurs to me now after reading that article. When I was told about it in the past, I understood it to mean that most people can only improve their VO2 max by about 10-20%, but that's not what it says. Instead it says that, after 20 weeks of following the programme described most people wouldn't expect to see more that a 25% increase, but it's not clear what would happen beyond the 20 weeks.

[NavigationHazard]

As I understand it, the actual VO2 max value is determined by measuring the oxygen and carbon dioxide concentrations of the air you breathe in and out. How far or how fast you get in the test isn't the important thing, only that you go sufficiently fast to achieve maximal oxygen consumption.

This last clause is a big part of the problem with 'not well trained' individuals. If you haven't done a flat-out 2k test before, the chances are pretty good that you're not going to go hard enough long enough to achieve maximal oxygen consumption at current fitness level. You're probably going to start out too fast, get into lactate trouble way too quickly, conclude in the back of your brain that you're going to die, and labor through debilitating pain that keeps you from processing as much O2 as you otherwise might. The more experience you have at the protocol, the closer your results will be to what they could be on the day.

As a general principle, distance and/or time aren't important in determining VO2max. But here, Hagerman used 2000m erg pieces as a standard test protocol for everyone -- and observed a correlation in his test subjects between performance and VO2max over the standard distance.

To my mind, there's a different confounding factor in the C2 Calculator. VO2max and the related value of power output don't actually scale linearly with body weight. Allometrically the relationship is more like to the ^2/3 power. Somewhere I have a paper from Seiler pointing this out, and proposing to scale relative VO2max values accordingly. If I find it I'll post it here. IIRC Seiler some years back was also proposing to collect VO2max and other data systematically for Masters rowers whose oxygen kinetics presumably have age-related differences. I have no idea what (if anything) became of this....

[tsourbier]

This last clause is a big part of the problem with 'not well trained' individuals. If you haven't done a flat-out 2k test before, the chances are pretty good that you're not going to go hard enough long enough to achieve maximal oxygen consumption at current fitness level.

We agree there! This is one explanation why for the same 2k time, untrained athlete shall have a higher VO2 than trained one...

As a general principle, distance and/or time aren't important in determining VO2max. But here, Hagerman used 2000m erg pieces as a standard test protocol for everyone -- and observed a correlation in his test subjects between performance and VO2max over the standard distance.

Are you sure? I would believe VO2 Max was measured in a separate normalized test and Hagerman tried to find the correlation between 2k time and measured VO2 max to achieve something similar to the Cooper test for running. It would be otherwise taking as hypothesis (2k is a good test for VO2) the conclusion one is trying to reach... that would be a design flaw in the research.

T.

[NavigationHazard]

Hagerman papers going back to the mid-1980s definitely refer to VO2max results derived from 2k tests or their functional equivalent. This one, for example, was predicated on a 6-minute erg test: Hagerman, F.C. "Applied Physiology Of Rowing," in Sports Medicine (1984) 1: 303. https://doi.org/10.2165/00007256-198401040-00005

Elite oarsmen and oarswomen possess large body dimensions and show outstadning [sic] aerobic and anaerobic qualities. Oarsmen have V̇O2max values of 6.1 ± 0.6 L/min and have incurred O2 debts of between 10 and 20 litres. The caloric expenditure of rowing estimated from the O2 cost of a 6-minute rowing ergometer exercise was calculated at 36 kcal/min, one of the highest energy costs so far reported for any predominantly aerobic-type sport....

Here's a link to Seiler talking (among other things) about scaling VO2max values allometrically: http://www.gslr.org/resources/NewsLette ... 0Rower.pdf See also Table 2 in it, which reproduces aggregated data including VO2max from a 1992 USOT 2k test conducted by Hagerman.

I'm under the impression that there is [was] a consensus going back to the early 1980s that national-squad-level rowers [if not necessarily ordinary mortals] hit VO2max during a 2k trial. That is, Hagerman may have taken it as a given in setting up his protocols.

[tsourbier]

Thanks for the links, interesting readings! As you pointed out, the first paper is great for understanding the specific physiological demands of the 2k and shows that it is not easy to suceed and elite rowers are a special breed. Hagerman certainly went to great length studying the rowing physiology.

Note that in this paper "An Update of Rowing Physiology" aimed at measuring adaptation to low intentisity vs high intensity training he specifies that "Aerobic capacity was measured by open circuit spirometry during a test of progressing exercise intensity on a Concept 2 ergometer.". So he’s not using only one type of measurement.

I'm still hunting the paper describing how those formula were obtained. The second paper you linked to said he collected data from 3000+ elite rowers no mention is made of his sample from the general population.

We can note that this is still a research subject in recent years:
https://www.scitechnol.com/the-use-of-a ... le_id=1810

[tsourbier]

Interesting read here:
viewtopic.php?f=3&t=4453
The wording on concept2 page seems to have changed a lot..

T.

[NavigationHazard]

Heh. Were "we" (including me) really posting here about this 11 years ago? Time flies....

[tsourbier]

Heh. Were "we" (including me) really posting here about this 11 years ago? Time flies....

Excellent, I didn't even realize Even this topic is now a few years old.

T.