vo2 max calculator illogical results

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Bob S.
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Re: vo2 max calculator illogical results

Post by Bob S. » January 27th, 2016, 1:46 pm

scootadaz wrote: VO2max (mL•kg-1•min-1) Classifications for Men
Age (years)Poor Fair Good Excellent Superior
20 - 29 ≤ 41 42 - 45 46 - 50 51 - 55 56+
30 - 39 ≤ 40 41 - 43 44 - 47 48 - 53 54+
40 - 49 ≤ 37 38 - 41 42 - 45 46 - 52 53+
50 - 59 ≤ 34 35 - 37 38 - 42 43 - 49 50+
60 - 69 ≤ 30 31 - 34 35 - 38 39 - 45 46+
70 - 79 ≤ 27 28 - 30 31 - 35 36 - 41 42+
That table is worthless. It doesn't go beyond 79 years.
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Re: vo2 max calculator illogical results

Post by jdlbb » February 4th, 2016, 9:49 pm

I'm a certified exercise physiologist and decided recently to start using the 2k row as part of my fitness evaluations as an alternative for the treadmill or step test. After getting some unexpected results while toying with the input criteria I created my own calculator in excel with the formula posted on the site. Here's what I've discovered:

(The following is for men)

If you're less than 165lbs:
The magic time is 7:20. Both "trained" and "untrained" will score the same Vo2 at this time, no matter what their weight(given its below 165lbs).
For times less/faster than 7:20, "trained" will score higher at a given time/weight(again, less than 165lbs)
For times greater/slower than 7:20, "trained" will score lower at a given time/weight(less than 165lbs)

If you're heavier than 165lbs:
The magic time is 8:20. Both "trained" and "untrained" will score the same Vo2 at this time, no matter what their weight(given its above 165lbs).
For times less/faster than 8:20, "trained" will score higher at a given time/weight(again, greater than 165lbs)
For times greater/slower than 8:20, "trained" will score lower at a given time/weight(greater than 165lbs)

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Re: vo2 max calculator illogical results

Post by tsourbier » February 23rd, 2016, 2:37 pm

thanks jdlbb for pointing out that they pusblished the formulas they used. Obviously those are wrong...

We can find them in "Heart Rate Training" as well:
https://books.google.fr/books?id=MW7lDn ... 29&f=false

I need to find the orginal paper to see how those were determined and were the mistake happened.

I emailed concept2 on the subject, my comments were forwarded to the folks in charge of that section of the site. We'll see if they come back to me ;)

T.

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Re: vo2 max calculator illogical results

Post by Garnett » September 13th, 2017, 5:17 am

Just came onto the forum looking for information on the same persiting erroron the c2 website.

Is it as simple as them getting "highly trained" and "Not Highly Trained" the wrong way around in their formula? - that's what it looks like to me.

Did Concept2 ever respond?

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Re: vo2 max calculator illogical results

Post by Gammmmo » September 13th, 2017, 5:30 am

Garnett wrote:Just came onto the forum looking for information on the same persiting erroron the c2 website.

Is it as simple as them getting "highly trained" and "Not Highly Trained" the wrong way around in their formula? - that's what it looks like to me.

Did Concept2 ever respond?
this was my initial thought :)
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Re: vo2 max calculator illogical results

Post by Garnett » November 3rd, 2017, 5:48 am

This has bugged me, so I had a look around. On the C2 Website, it states the formula used for the calculation.

I have plugged that into a spreadsheet, and my implementation of that formula outputs the same (faulty-looking) results as the C2 website implementation - I've tried to share it so anyone can see:-

https://docs.google.com/spreadsheets/d/ ... sp=sharing

On that basis it appears that the actual description of the formula is incorrect...

From the C2 website it appears the formula is based on studies by Dr. Fredrick "Fritz" Hagerman at Ohio University. Unfortunately Dr Hagerman passed away 4 years ago. I have had a quick look around and cannot find any further descriptions of the formula suggested by his findings, so I've hit a bit of a dead end.

Hopefully this might help someone else take up the project...

In case it's not visible, the formula I created for Google Sheets was:-

=1000/B3*(IF(B1="Male",IF(B6="Highly Trained",IF(B3>75,15.7-(1.5*(B4+(B5/60))),15.1-(1.5*(B4+(B5/60)))),10.7-(0.9*(B4+(B5/60)))),IF(B6="Highly Trained",IF(B3>61.36,14.9-(1.5*(B4+(B5/60))),14.6-(1.5*(B4+(B5/60)))),10.26-(0.93*(B4+(B5/60))))))

...Where Cells B1 through to B6 were:-
  • Male or Female?
    Age (yrs)
    Weight (Kgs)
    Best 2K Time Mins
    Best 2K Time Seconds
    Highly or Not Highly Trained?

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Re: vo2 max calculator illogical results

Post by NavigationHazard » November 3rd, 2017, 7:27 am

Keep in mind that VO2max isn't an absolute value. It's a measure of oxygen uptake at current fitness level as determined by incremental exercise, expressed as milliliters per kilogram of body weight per minute (ml/kg/min). Changes in either the numerator or denominator (or both) will affect the results. Gain weight, other things equal, and your VO2max value will drop; lose it, other things equal, and your VO2max value will increase. Alternatively, get fitter (or just more familiar with the testing procedure), other things equal, and improved performance will raise your measured VO2max value. Lose fitness, other things equal, and VO2max values will drop.

If you think about what highly trained/not highly trained implies in terms of performance ceilings, Hagerman's formula makes sense. Take a hypothetical 100 kg male with a 6:30 2k. Plug in "highly trained" and the C2 calculator suggests rower A's VO2max is 59.5 ml/kg/min. Plug in "not highly trained," everything else the same, and the calculator comes up with 48.5. To my mind, what this implies is that if rower B really is "not highly trained" and is still factually capable of a 6:30 with a comparatively low VO2max, he's probably able to improve his performance dramatically by training. If he becomes "highly trained." he will wind up with a significantly higher measured VO2max than that 48.5 and almost certainly will be a lot faster than 6:30. Why is this surprising or counterintuitive?
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Re: vo2 max calculator illogical results

Post by Garnett » November 3rd, 2017, 11:54 am

You've hit the nail on the head there I think.

I emailed Concept 2 without much expectation of a reply, so I was pretty impressed to get a response less than 24 hrs later...

"As you have probably seen in the FAQ section under the calculator, the formula used by the calculator was created by Dr. Fritz Hagerman. He collected many thousands of actual data points over many years of research and correlated the results between VO2 max and 2K scores. Unfortunately Dr. Hagerman died a few years ago, but if you google his research you will find many papers related to VO2 max and the work he did for US Rowing.

Essentially, consistent aerobic training increases your VO2 max. Not infinitely, but it increases it. So for a given weight and 2K score, a highly trained athlete would have a higher VO2 max than an athlete without the same background of consistent training. The athlete that isn’t highly trained is able to produce the same 2K score at the same weight with a lesser VO2 max because they have other advantages – that could be a greater ability to tolerate lactic acid, more natural power etc… Given time and by becoming highly trained that same athlete would be able to improve their VO2 max and their 2K score."


I put the confusion down to the ambiguity in the concept of "highly trained".

I mistakenly interpreted this to denote whether the rower had technique training in rowing efficiency. What it actually refers to is the rower's level of consistent aerobic (ie physical) training.

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Re: vo2 max calculator illogical results

Post by tsourbier » November 5th, 2017, 10:44 am

I still think there is something flawed with this formula and reasoning.
If you think about what highly trained/not highly trained implies in terms of performance ceilings, Hagerman's formula makes sense. Take a hypothetical 100 kg male with a 6:30 2k. Plug in "highly trained" and the C2 calculator suggests rower A's VO2max is 59.5 ml/kg/min. Plug in "not highly trained," everything else the same, and the calculator comes up with 48.5. To my mind, what this implies is that if rower B really is "not highly trained" and is still factually capable of a 6:30 with a comparatively low VO2max, he's probably able to improve his performance dramatically by training. If he becomes "highly trained." he will wind up with a significantly higher measured VO2max than that 48.5 and almost certainly will be a lot faster than 6:30. Why is this surprising or counterintuitive?
Take 2 individuals with the same VO2 Max one "highly trained on the erg" and the other "untrained". Which one would you bet on? One would think that the trained athlete is able to fully tap in his potential and have a much better time that the untrained athlete. Isn't it why training is for?

To take back your values, 100kgs vo2 max 59 (very good but not out of this world value for a 100k athlete) and let's find what the calculator gives us

trained athlete => 6'32
untrained athlete => 5'20 :shock: :shock: :shock: (the current world record is at 5:36.6 for the concept2 website it is held by an olympic champion rower -Rob Waddel-, I'd like to see it beaten by an untrained athlete... I'll be even more eager to see what that athlete is capable of once trained!).

As pointed out in the reply from Concept2 the VO2 max cannot increase infinitely, at the end it is bound to how much blood you can pump through your muscles. Training certainly helps you to increase your VO2 Max to its "potential" but also makes you more efficient at transmitting the energy you consume to the erg.

Certainly as a coach, if an untrained and trained athlete have the same 2k time, I will see more "potential" for improvement in the untrained athlete. Is that to say that athlete has a lower VO2 max but other physiological advantage? Not really, I would say that on the contrary the untrained athlete has been able to "waste" more energy for the same results (thus probably has a higher (not lower) VO2 Max than the trained athlete). The purpose of training is to increase the VO2 Max AND those other factors (lactate tolerance, pacing, power, efficiency, etc...). The explanation provided by Concept2 is not satisfying.

The example chosen clearly shows that the formula must be flawed somewhere,

T.

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Re: vo2 max calculator illogical results

Post by NavigationHazard » November 5th, 2017, 2:38 pm

tsourbier wrote:Take 2 individuals with the same VO2 Max one "highly trained on the erg" and the other "untrained". Which one would you bet on? One would think that the trained athlete is able to fully tap in his potential and have a much better time that the untrained athlete. Isn't it why training is for?
The hypothetical "highly trained" athlete and the putatively "untrained athlete" we've been comparing have the same stipulated 2k time. The point is precisely that the former has actualized most (or possibly even all) of his oxygen-processing potential, while the latter almost certainly hasn't.
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Re: vo2 max calculator illogical results

Post by JerekKruger » November 5th, 2017, 2:59 pm

My guess would be the two data sets the formula is derived from don't overlap that much. How many novice rowers with little to no rowing experience (the definition given) are going to pull sub 6:40, and how many elite, national and top college level rowers (again the definition used) are going to be slower than 6:40? Similarly I suspect relatively few of the not highly trained rowers are going to have had VO2 maxes above 50 whereas for the highly trained rowers over 50 might have been fairly typical. That the formula breaks down when you go outside of the typical values of the original data sets is not all that surprising to me.
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Re: vo2 max calculator illogical results

Post by hjs » November 5th, 2017, 3:37 pm

JerekKruger wrote:My guess would be the two data sets the formula is derived from don't overlap that much. How many novice rowers with little to no rowing experience (the definition given) are going to pull sub 6:40, and how many elite, national and top college level rowers (again the definition used) are going to be slower than 6:40? Similarly I suspect relatively few of the not highly trained rowers are going to have had VO2 maxes above 50 whereas for the highly trained rowers over 50 might have been fairly typical. That the formula breaks down when you go outside of the typical values of the original data sets is not all that surprising to me.
Bit depending on general fitness, but I think not many toprowers did not pull sub 6.40 on a first go. Untrained does not mean unfit.
Vo2 max is also relative poorly trainable, its mostly a matter of talent.

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Re: vo2 max calculator illogical results

Post by JerekKruger » November 5th, 2017, 3:53 pm

hjs wrote:Bit depending on general fitness, but I think not many toprowers did not pull sub 6.40 on a first go.
Sure, I'm not saying none of the not highly trained set went sub 6:40, but I think it's relatively safe to say most wouldn't have. Back when I was a novice rower at uni only one of my fellow rowers pulled sub 6:40, and he was a varsity level middle distance runner. Most the rest of the novices pulled low 7s with a handful of sub 7s as well. Similarly I saw a video of an Imperial College Novice 2k test where the best time was in the low 6:50s or high 6:40s.
Untrained does not mean unfit.
Indeed, and in fact the calculator doesn't use the term "untrained" but rather uses "not highly trained" and actually specifies "novice rower with little or no rowing experience". I'd be surprised if many of them hadn't already done some other sports before.
Vo2 max is also relative poorly trainable, its mostly a matter of talent.
Yep, in some people it doesn't seem to respond to training at all apparently, and in most a 10-20% increase over your untrained level is as much as they can expect.
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Re: vo2 max calculator illogical results

Post by NavigationHazard » November 6th, 2017, 3:35 am

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. Here we're talking about an observed correlation between 2k erg tests and measured VO2max. I submit that doing a 2k erg test well is >not< particularly intuitive, and that performance on them is highly trainable.

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
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Re: vo2 max calculator illogical results

Post by tsourbier » November 6th, 2017, 3:44 am

NavigationHazard wrote:
tsourbier wrote:Take 2 individuals with the same VO2 Max one "highly trained on the erg" and the other "untrained". Which one would you bet on? One would think that the trained athlete is able to fully tap in his potential and have a much better time that the untrained athlete. Isn't it why training is for?
The hypothetical "highly trained" athlete and the putatively "untrained athlete" we've been comparing have the same stipulated 2k time. The point is precisely that the former has actualized most (or possibly even all) of his oxygen-processing potential, while the latter almost certainly hasn't.
If the formula is said to predict 2k time from VO2 max then it can be reversed to estimate 2k time from VO2Max, this makes it easier to judge if it makes sense or not.

The formula says that for male hwt going sub 8:20 for the same VO2 Max the untrained athlete goes faster than the trained one. If there is any kind of truth to that my only advice to any athlete would be to get fit and work on his VO2 max while cycling or running and stay away for the erg/boats as much as possible as it would make them slower :mrgreen:

T.

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