Vlamax from power testing only

[Kalle Arsch]

...that's what INSCYD claims can be done

Does anyone here have further insight into the topic?  I searched researchgate and the like, but I could not find any method that would outline how this can be done.

All I found were the classic sprint tests with subsequent lactate measurements.

This could be the next killer-feature of GC ;-)

[dane...@gmail.com]

I think INSCYD is somewhat based on the work of A Mader(?) and Jan Olbrecht. 

You can find some of the same graphs from INSCYD in "A Theory of the Metabolic Origin of "Anaerobic Threshold"" (Mader and Heck, 1986) and then an expanded model can be found in "Glycolysis and oxidative phosphorylation as a function of cytosolic phosphorylation state and power output of the muscle cell" (Mader, 2003).

Both papers can be coded in Excel, so I'd imagine someone smart could do this in Python. I've found quite a few INSCYD athlete reports online from people posting them in random places and have found some of their testing protocols. Mostly varying power targets with blood lactate measurements as specified time intervals after the work interval. The model likely uses power and blood lactate as the input to estimate a bunch of other parameters in the system of equations.  

I'm definitely interested in finding out more.

[Kalle Arsch]

I'm pretty sure you are correct about the basis being Mader/Olbrechts work.  If you know the Vlamax and VO2max a MLSS can be simulated.  That basically yields the curve that STAPS (also founded by Sebastian Weber) put in their logo.
However the "novelty" is, that there is power-only testing protocol for cycling that eliminates the need for lactate/o2/Co2 measurements and claims to come within some odd 2.5% accuracy for Vo2max/Vlamx/MLSS/substrate utilization.
As far as I understand it, it's partly similar to W'/AWC/FRC:

Measure total workload

subtract anaerobic work

add a CP-test, just in case ;-)

yield aerobic work

make a model ;-)

I can imagine it can be more accurate than, say W'/FRC, because for one the testing protocol is more precise: i.e. the sprint test is supposed to be as anaerobic as possible (performed from complete rest >90sec).  Sebastian said in a podcast when you coast at your Z2 and then throw down a 20sec sprint, than the work produced is not purely fueled by the anaerobic system, because your metabolism was already producing x-Watts with your metabolism being in homeostasis at start of the sprint...

Anyway- interesting stuff.  If anyone has further info on how to DIY such a test... I'm interested ;-)

[itimation]

Does anyone know the exact Protocol to ride for the Power-only Testing?
As VLamax and PeakPower (maybe rather W/kg than absolute Power?) from a sprint correlate very high, and there should be a negative correlation with longer duration MMP, I think it should be possible to get some good guesses if you have different power/time numbers. In the end it also would be interesting to have a rough estimate like low/medium/high/very high and see if there is a (significant) change within season/training period

[Kalle Arsch]

the protocol is nothing too elaborate, there are some interviews out there where Weber talks about them.

15-20sec max test (from complete rest)

2.5-3.5 max test (not sure if from rest)

5-7 min max

10-12 min max

so basically same protocol as a Vlamax and a CP test.  I assume the longer intervals are just to validate the outcome of the simulation, because to plot "lack of pyruvate & lactate accumulation" graph you only need two values:  Vlamax and VO2max.

In other words: all the data would already be in GC provided that you "clean the data sets"- basically only accept values in the MMP-model that comply with the protocol below 3.5 minutes.  The same "knowledge" from the INSCYD test is already somewhere in the MMP ,-)

[Kalle Arsch]

I did some further digging and found a couple of papers that contain the "basic" calculations used, mostly Maders work...

If my understanding is correct the set of 7-10 equations basically solve for MLSS based on known VO2max and Vlamax.  INSCYD somehow also seems to be able to calculate the VLamax from a sprint test with only power.... but I guess the calculations could also be used "in reverse":  Since VO2max and MLSS can be approximated from the MMP and ACSM-formula or derivatives for VO2max, VLamax could be calculated.

Here are the papers that I found:

https://monarch.qucosa.de/api/qucosa%3A20237/attachment/ATT-0/

https://tbiomed.biomedcentral.com/articles/10.1186/1742-4682-11-25

https://tbiomed.biomedcentral.com/articles/10.1186/s12976-016-0044-3

[raf...@tfrank.de]

Interesting topic and nice literature finds, thank you. Currently reading them.

In the meanwhile I find it highly interesting that WKO5 now also added a model for WKO5. But as interesting as this fact alone is the background article by Kolie Moore (https://www.wko5.com/vlamax-in-wko).

And no, of course not the background on their implementation of the model - that is to anyones guess as it is closed shop as anything in WKO5. It's more on the background why they implemented it. But even that is obscure. Seems more like the only reason Kolie has written that piece is to somewhat hint at the fact that VLa Max would be on the top of the list on what metric everyone seems to want in WKO5 and at the same time while he believes everyone wants it for moot and the wrong reasons. And for the reason he thinks it's worthwhile he also mentions that there are far more direct measurements already available (sprint power).

He backs up his reasoning with a short excursus into the possible model errors and the substrate usage of the muscle cells and I think his angle merits some further discussion/consideration (i.e. about his titled 'mis-use of VLa Max). Food for thought and I wish he and Sebastian Weber and other people with the needed background could discuss this in a civilized manner (does it show that I may have come across to many Kindergarten threads of sports 'scientists'  with a bit too much of an ego? ;-))

[Mark Liversedge]

Quantifying  contribution to the power duration relationship from different energy systems is built in to both the WKO5 and GC models.

This isn't anything particularly new tbh. I suspect INSCYD stealing TrainingPeaks coaches and especially pro teams and institutes is what has motivated this being added to WKO5.

Mark

[Damien LE MESNAGER]

Do you have any new information about this model? How is it functional? What are the equations etc?
Personally I have trouble understanding how it determines Vlamax and VO2max...

Thanks in advance!