jam pants said:Would you have felt comfortable submitting that paper for peer review?
Me? No, at least not the way it was written/presented. But, my standards for myself are higher than average.
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jam pants said:Would you have felt comfortable submitting that paper for peer review?
ScienceIsCool said:I picked Sassi's paper at random. Very interesting, but I'm not sure it supports your central hypothesis. First paragraph of the discussion:
"GE and EC, despite of their in-subject seasonal waves, did not show changes related to those of other maximal and sub-maximal parameters of aerobic fitness" That seems odd to me. You think they would track nicely if the GE changes were due to training.
ScienceIsCool said:As for the GE and EC changes themselves: the authors cannot exclude the possibility that the improvement over a season wasn't due to their methodology. They changed from measuring at 78% PPO (Peak Power Output) to 73% PPO in later measurements. <Paragraph 3 of the discussion> They even give a proposed mechanism for why that change would affect their measurement of GE and EC.
I could go on, but I have to admit that I'm kind of disappointed. In a more formal setting, I would even be tempted to use this paper to refute the idea that GE can be improved through training when using a trained subject and the sport they are accustomed to.
Did I completely miss something?
John Swanson
acoggan said:If you wish to whittle the list to just those studies using trained cyclists, it would look like this:
Paton and Hopkins J Strength Cond Res 2005; 19:826-830
Sassi et al. Appl Physiol Nutr Metab 2008; 33:735-742
Hopker et al. Med Sci Sports Exerc 2009; 41:912-919
Hopker et al. Appl Physiol Nutr Metab 2010; 35:17-22
Sunde et al. J Strength Cond Res 2010; 24:2157-65
acoggan said:I cited that study simply because it is a longitudinal investigation of changes in gross efficiency resulting from endurance exercise training, i.e., in that regard it is similar to the others. If you wish to whittle the list to just those studies using trained cyclists, it would look like this:
Paton and Hopkins J Strength Cond Res 2005; 19:826-830
Sassi et al. Appl Physiol Nutr Metab 2008; 33:735-742
Hopker et al. Med Sci Sports Exerc 2009; 41:912-919
Hopker et al. Appl Physiol Nutr Metab 2010; 35:17-22
Sunde et al. J Strength Cond Res 2010; 24:2157-65
Plus the recent Hopker et al. paper, as well as a few others published between 2010 and now.
(Note the correction in the volume number of the first reference.)
In contrast, here's a list of all the longitudinal studies (of untrained or trained individuals) that I have been able to locate reporting that efficiency does not change:
Roels et al. Med Sci Sports Exerc 2005; 37:138-146
As for the role of biomechanics vs. biochemistry, it doesn't really matter to the question at hand, i.e., either efficiency is changeable, or it is the immutable "Holy Grail" that Ashenden claimed it was.
Finally, gross efficiency increases with increases in absolute exercise intensity, as the impact of the intercept of the VO2-power relationship becomes less and less - this is what the authors meant by "PO-dependency".
acoggan said:Not if different physiological mechanisms were involved.
Yes: the fact that gross efficiency tends to plateau at high power outputs, such that the difference between 78% and 73% of peak power output would not matter.
Anyway, keep scrounging...I'm sure you'll come up with a way to dismiss all of the other papers as well.
acoggan said:http://www.ncbi.nlm.nih.gov/pubmed/19941249[/url]
ScienceIsCool said:I swear that I am taking only random samples of your citations.
sittingbison said:forgive me if I'm completely wrong, because I'm not a scientist and don't know what I'm talking about. But isn't all this a big stinking pile of BS?
Because again forgive me if I'm wrong, but wasn't Armstrong doping since a teenager with Carmichael, and admitted to taking Test, EPO, steroids, insulin and some other stuff in 1996? So how the frak can a physiological study (purportedly about normal elite athletes (if there is such a thing)) of Armstrong when he was juiced to the gills have ANY relevance to anything ?
And I didn't even mention Ashenden et al having misgivings about the methodology (I gather they don't see eye to eye). Such as LAs weight and height being misreported etc.
Random Direction said:Unfortunately acoggan's approach here seems to be one of showing credentials and waving a bunch of studies. When ScienceIsCool and others dig in and try o find out for themselves, they get criticized for not being expert in the field. Given this reaction, my intuition is that it is not science that is being debated, but instead 'science' is being improperly used to back up a predetermined world-view.
ScienceIsCool said:Can I ask what those physiological mechanisms are?
DirtyWorks said:Winner! Winner! Turkey dinner! Then Acoggan resorts to a personal attack, labeling you a conspiracy theorist. http://forum.cyclingnews.com/showpost.php?p=1034627&postcount=382
DirtyWorks said:The bad news here is the fundamental scientific process is sound, yet here's another instance where it seems Acoggan has used the process to meet some other non-scientific goal.
the big ring said:you appear to imply being cited 56 times somehow indicates soundness?
acoggan said:On the contrary: my point was that Coyle's paper has been rather middling in its direct impact (at least compared to the rest of his work), and seems to continue to be cited at about the same frequency after as before all the Letters-to-the-Editor.
acoggan said:I'm not sure I'm clear on your exact question, but you acted surprised that VO2max, LT, and efficiency did not change roughly in parallel. My point is that you wouldn't expect them to unless there were some common mechanism responsible.
For example, let's consider training-induced changes in VO2max and efficiency. The former is dependent upon changes in maximal cardiac output (stroke volume, actually, since maximal heart rate tends to go down w/ training) and a-vO2 difference (influenced by changes in capillarization, etc.), and plateaus relatively rapidly after someone takes up endurance sports (e.g., I started racing at age 15, had a VO2max of 80 mL/min/kg when I was first tested at age 18, and could still hit that figure when I was age 32).
The mechanism(s) responsilble for changes in efficiency, OTOH, appear (emphasis on appear, because this is still a rather open question) to be linked to changes in skeletal muscle biochemistry/characteristics, e.g., changes in myosin expression/contractile properties, uncoupling protein levels, calcium handling proteins, NOS enzyme activity, etc.). These particular adaptive mechanisms could very well follow a different time course, and/or have a higher potential for improvement, than changes in VO2max. If so, you would not expect VO2max and efficiency to always track one another.
ScienceIsCool said:To your second point, I thought the authors very clearly disagreed; that the slow VO2 something-or-other would make the 78% vs73% difference matter. They very clearly made the point that they cannot rule out that this was the cause for the measured change in GE.
ScienceIsCool said:So if you're correct and it takes some long term physiological changes to the fibers themselves then it would take a very long term study to show this.
acoggan said:Clearly the authors were just being cautious in acknowledging this as a theoretical limitation (for which I commend them). In reality, it is quite unlikely to explain their observations, because gross efficiency was measured at a power output (i.e., 337 +/- 44 W) well below the power at "threshold" (in this case, quantified as the respiratory compensation point) (i.e., 465 +/- 43 W), meaning that the slow component to VO2 would be essentially non-existent.
ScienceIsCool said:Oh, Christ. "Results of both experiments in this study demonstrate training related increases in GE, but not V˙O2max."
I wasn't able to access the entire study, but came across the full abstract. Really? The cyclists trained, but didn't increase VO2max!? Were these trained or untrained cyclists? Athletes, or "off the couch" performers.
ScienceIsCool said:Dr. Coggan, what am I missing? Please, give a semi-layman's (scientist in a different field's) explanation of why GE in a trained athlete changes with training. Please give *relevant* citations.
ScienceIsCool said:I swear that I remain open-minded and cognizant that this is not my field. Not impressed so far. I only have so much free time, so will only take random samples of your citations until I make my way through them. If you have any citations I should focus on, I would welcome the suggestion.
As an aside, abstracts are useless. Full papers or GTFO.
the big ring said:The power at threshold was between 422 and 508W?
the big ring said:So if the studies in the review are cited more often, that would make them more sound, yes?
acoggan said:"Thirteen subjects (mean ± SD: age 26 ± 4 years,
body mass 67.4 ± 7.2 kg, height 178 ± 5 cm, _V O2 max
74.7 ± 4.9 mLkg–1min–1) were involved in the study: 8
professional road cyclists (3 of whom finished in the top
5 places of the Giro d’Italia or Tour de France overall
final ranking) and 5 mountain bikers competing at the international
level (with 4 out of 5 being current members
of the Italian National Team)."
ScienceIsCool said:So if you're correct and it takes some long term physiological changes to the fibers themselves then it would take a very long term study to show this. Am I correct?
ScienceIsCool said:Am I also correct that this should be of intense interest, because of the implications? Understanding and manipulating GE through a specific training regime could give an athlete a very large advantage in an endurance sport like cycling.