Thanks Spaniel. I will do my best.
My focus has been to get the brain into the discussion. I am not a neurophysiologist and know desperately little about the brain and how it works. In the laboratory I believe we study subconscious controls when we have subjects do activities with which they are unaccustomed (exercising at a fixed rating of perceived exertion) and we expose them to changes in the oxygen content of the inspired air which they have usually not ever experienced before. I would not understand how under these conditions, the changes that occur in their exercise performance are due to conscious controls. But again I may be wrong. Similarly when they exercise in the heat or the cold, we are able to explain (ie predict) why they change their exercise performance on the basis of biological signals that I don't think are being perceived at a conscious level by the subjects. I do not know that we consciously know how quickly our bodies are heating up - this is the biological signal to which the brain is responding under these conditions.
The point is that we study pacing strategies in response to some environmental pertubation; we don't study pacing strategies in athletes in competition in which there is no pertubation. So anything we say about how athletes pace themselves in competition is purely a theory based on the model of subconscious control we believe we have identified in laboratory studies. But it has to be fairly obvious that conscious controls also exist. We can clearly override the CG - I did it many times in my running career - but I also learned, especially in the 56mile Comrades marathon, that if you went too fast early on in the race, sooner or later the "bear" would jump on my back and I would "hit the wall" and whatever I might consciously wish to happen would simply not happen, however hard I willed it to happen, or prayed for assistance, or whatever. At the time I believed that this "fatigue" was due to changes in my muscles - "peripheral fatigue". Now on the basis of what we have found - in particular the finding that under these conditions we are activating less than perhaps 40% of the fibers in our active muscles - it seemed more likely that our effort was being regulated centrally in the brain. Because if it were not, the brain would logically recruit progressively more muscle fibers until all were active at which time and only then would we be exhausted.
After I had learned how to train for that race, I also had to learn how to run the race. I learned that the key was to study the final 25km of the course and then for the last month or so before the race, to imagine myself running over the course, memorizing each hill and its exact distance. Only when I did that was I able to speed up at the end and run the last 2 miles faster than any other section of the race. This endspurt taught me that the cause of my fatigue could not have been "peripheral fatigue" since it was reversible at least for a short time. And if exercise was regulated only by "peripheral fatigue" why was it necessary also to prepare my brain for the last month (at least)?
During those runs I also learned that it requires all your conscious effort just to MAINTAIN your pace; it was quite impossible to will yourself to speed up, except in the last mile or so.
Hill never discussed the role of the brain in determining exercise performance. I have personal copies of all his books and I can find no such reference. But he did write that in skilled activities the brain co-ordinates and determines the response. Why he did not discuss conscious controls during exercise I have no idea. Perhaps he did not think the brain was important since in his view exercise was regulated in the periphery. But if he had included an opinion that the brain played a role, exercise physiology would have been different in the past 90 years and this blog would probably never have happened.
With regard to your 2 propositions, proposition 2 seems more probable. You train your body to be able to maintain homeostasis at a higher rate of energy expenditure (oxygen consumption). This allows you to run faster without endangering homeostasis. But there has to be more to it than that since it seems that the governor is conservative and it does insure that there is quite a large reserve. I conclude this on the basis that athletes can change their performance quite suddenly (i) without dramatically increasing or altering their training if they believe what their coach tells them - the performance of John Landy discussed earlier is a case in point. Or (ii) by adding a few sessions of speed training to their normal aerobic, base training. So you might be able suddenly to teach the governor to be less conservative (at least for a period although this too will be reversible). I also think that in disease states, the governor suddenly becomes even more conservative.
I have additional evidence for these statement that I will share in due course if we are able to get it published.
Thank you for agreeing that the Hill model is fatally flawed since it absolutely does not allow for the brain to influence the exercise performance.
In contrast we have provided irrefutable evidence that exercise performance is regulated by a complex intelligent system and we have published that work in a number of peer-reviewed journals. The CG does not exist purely on the basis that the Hill model is "fatally flawed" and needs to be replaced. We have real data that presently support the predictions of the model.