People who undertake resistance training are not sedentary though, correct? Sedentary people do not have the same MPS requirements as trainees, even when those trainees are having a day off? It seems to me that dosing PA on off days would still be beneficial in terms of maximising levels and MPS, no?
Also, there can be a difference between something being anti-catabolic, and something being pro-anabolic?
Their theory on using it on off days to increase mTOR to enhance recovery is based on the theory that the PA will act at the intracellular level. At the time they did the Tampa strength training study, they have not yet done the sedentary people study (as the Tampa strength training with PA study even notes that sedentary people/muscle wasting should be investigated, implying they didn't have the en vivo data for that yet). They were still assuming that the PA may have the endogenous PA effect.
Think about how PA typically works. It actually doesn't need physical stimuli to act on mTOR (that was mentioned in the Q&A thread as well). It's a signaler and also attaches itself to mTOR. Based on that assumption of how PA works, it makes sense to take it at other times outside of the period in which physical stimuli is present (exercise), assuming that the PA would make its way to a significant degree into the phosopholipids pool of cells. Thus why the sedentary people study is of importance here, going by what is understood of how endogenous PA works, the sedentary subjects should have demonstrated increased anabolism from PA supplementation. Alas, they did not.
So IF you take the result of the sedentary people study along with Tampa's cell culture data AND previous cell culture data, it would become evident that the way supplemental PA works is that it will have the mTOR effects we are looking for WHEN it is available in circulation in your body (serum) around periods of physical stress (exercise) because that is the window in which PLA2 is present at the extracellular level (due to sufficient physical stress placed on cells, leakage basically).
Thus what Stout and Wilson were talking about 9+ months ago, that was when they did not have the results from the sedentary people study and thus assuming that PA supplementation may have significant intracellular activity to stimulate mTOR. Thus going by that logic, when you take it on off days and if it made it into cells to a significant degree, it should keep you more anabolic.
Another thing to note, notice what Stout was talking about when he talks about keeping serum levels high with PA around workout time. The reason this is suggested, again, is based on PLA2 being present at the extra cellular level to convert the PA to LPA. This is also likely why Wilson and Stout suggests higher PA doses may be better, because you now have more of it circulating giving you a higher percentage of PA converting to LPA.
PA is also not anti-catabolic. It's pro-anabolic in terms of what it does at the intracellular level as it is a signaler for mTOR (anabolism). Exogenous PA however is indirectly anabolic, it's actually providing the substrate for LPA, LPA engages ERK and that leads down in a cascade in which it will stimulate mTOR.
Leucine is also directly anabolic, it is indirectly anti-catabolic. The anti-catabolic activity is actually due to the increase in insulin. Insulin is anti-catabolic, leucine increases insulin release. Just an interesting tidbit for you there.
Also. note
De__eB:
Saw your message. I did read the Tampa study thoroughly. Please note in that study they mentioned that investigation of PA's anabolic effects for the use of muscle wasting/sedentary populations should be conducted. At the time that Tampa strength training study was done, they did not have the data on sedentary subjects yet. Their theory on how it may work on sedentary subjects is actually based on the assumption that PA may make it into cell phospholipid pools. That did not pan out in the sedentary subjects study, which was never published since it was funded by ChemiNutra and one of their main bullet points in their patent (obviously it was never published because it didn't work, thus throwing the theory out the window at least for now, and it obviously doesn't look good for ChemiNutra to have a study disprove one of their talking points for Mediator, I'm guessing ChemiNutra owns the study and decides to publish it or not? or it may be that it's under peer review? this was months back that Wilson mentioned it on a podcast somewhere).