If Tim Noakes "Central Governor" Model is Correct AND there is NO Lactate Threshold, HOW should this effect my train

Sim,

The myosin ATPase is the enzyme that "breaksdown" ATP. The *ATPsynthase* in the mitochondria is the enzyme the is responisble for making "aerobic" ATP, while ATP made through glycolysis is a product of a metabolic reaction and referred to as "substrate level phosphorylation".

The myosin ATPase acts as a limiter in that the muscle can only contract as fast as the Myosin ATPase can use the ATP. Using the car analogy again, you can have a Volkswagen Fox with a huge gas tank (lots of fuel; ATP), but with the 4 cyl engine, you can never beat the the Ferrari GT, the Fox just can't use the fuel fast enough. Whether the Myosin ATPase is designed specifically with that limitation or, it's reliant on the thermodynamics, probably a bit of both. As I've alluded to previously though, the general theme that tends to evolve in physiological systems is that the system is only as strong as it's weakest link, and so, the speed of Myosin ATPase is related to the other factors (e.g. mitochondrial content, anaerobic capacity, etc) with which this component of the system must interact.

"In a bike if one system is functioning sub maximally then the overall performance is limited even if the other systems could increase that performance.

In a body i would assume the same and so far this supports peripheral control."

Yes, this is the point I have tried to make on a number of occassions, using the previous car analogy, and making reference to some physiologists, Wagner in particular, who take this view.

Total central control?? Well in Control Systems discipline, some use the example of auto pilot in jet planes. Today's jetliners can essentially fly on their own, but they are very susceptible to individual system component malfunction/failure. Therefore, there need to be numerous levels of redundancy in order to protect the plane from crashing. These levels of redundancy occur at various places peripherally, in the system, so that if there is a problem with an individual component, it does not result in a catastrophic failure. The autopilot still makes the major decisions, which way to go and how fast, but many of the details are ironed out peripherally, especially when the system is taxed.

The cause of rigor mortis in a dead person is simply the lack of ATP. There may actually be glycogen present in the muscles, if the dead person were "carbed up", but the processes of making ATP have stopped and as a result the muscle can't relax.

Hope this helps.

Steve

sure, i did the decathlon for Australia and i guess that narrows it down to two. I guess i am not too many hours out of your timezone, although not as close as Perth which is where i was living in 96. I have a background in applied science majoring in physical education and sport psychology. Started honours but then time to travel overseas to compete so i stopped there. Probably the biggest influence was my coach Efim Shuravetsky who was coaching me even whilst i was a student. Very lucky as he somehow helped refine all that i learned directly into a practical sense (well to a degree). He was a very good coach and a very good human being. Perhaps if he was more ambitious he would have produced some great athletes. As it was he was one of the coaches of Nikolai Avilov and he has the best record in decathlon in Australia of any coach. Another possibly equal influence was his son Julian, my pole vault coach. He has a way of looking into things that is quite rare and his mechanical approach, although different to Efim's, has been extrmemly helpful to me.

I think it is important to have teachers, coaches and then guides. A person who can fulfill all three roles over time. I see Arthur and Percy and also Efim as people that can achieve this.

By the way Efim went through the process back in the Ukraine. He did the 4 year sports coaching degree specialising in track and field after being a national level athlete himself and then became a coach in the system. Heavily educated in the embryonic but pure and still accurate sports sciences. he was lectured by the guy who came up with periodisation before Bompa put it out for all, but i cannot remember his name.

Influences are important. The sports science and sports coaching influences are quite intwined. Possibly to become moreso?

Thanks Steve i'm somewhat clarified especially with my mistakes in the physiology. Interesting bit we need ATP to relax. Bascially we need to be alive in order to relax. The more alive we are (i'm linking ATP to aliveness here somehow) the more relaxed we can be? Bit of a leap!

I didn't realise there was a discipline called Control Systems. What is the natural end point for any artifical control system? The Arificial intelligence i guess, in robotic form possibly. In such a future situation if one of these peripheral systems failed and there were levels of redundancy to protect a catastrphic situation, would R2D2 be alerted to the crisis and roll off down to fix it? Does R2D2 symbolise say, a white blood cell being alerted to the presence of an intruder in the system and being told where to go? Or the increased production of such cells to combat this problem.

Possibly mechanical systems aren't a good analogy to the human system as they aren't driven by an intelligence such as the human mind possesses. Future machines, as we speculate, could contain such central government? The Borg have taken it to another level again i i guess.

Dear Steve,

I am not sure if my last post covered all these issues - so let me try here..

YOU WROTE:

Your statement:

"Muscle glycogen depletion reduces the capacity to produce ATP and must therefore cause the muscle to run out ATP if there is no nervous control."

Does not necessarily lead to your next statement:

" ATP depletion causes the muscle to go into rigor (irreversible contraction)."

As I stated in my response, glycogen depletion certainly reduces the capacity to produce ATP at a high rate, but glygocen depletion does no necessarily result in "rigor". McArdle's patients do just fine at activities of daily living, and actually, the "second wind" phenomenon appears to alleviate the rigor or contracture if you will, to a very large extent. So, as I pointed out, glycgoen depletion simply means that rate of ATP provision is limited.

MY ANSWER:

McArdle's patients have a brain and this could protect them from developing rigor.

My point is that in the absence of any other influence or control, a muscle without ATP cannot relax and hence goes into rigor. That is a biological law. Thus if the muscle cannot produce ATP sufficiently rapidly it has to end in rigor. The idea that the muscle will simply slow down is part of the peripheral model thinking that has gone unchallenged because of the logic that "we know that is how the system works". But how does a reduced rate of ATP production causes the muscle to reduce its force production? I am not sure that anyone has ever really tried to produce an explanation for that mechanism.

YOUR WROTE:

Further, this statement:

"Since rigor has yet to be described in healthy people during exercise and since muscle ATP concentration remain within the normal range even when the muscle has (almost completely) depleted its glycogen stores, so there must be a regulation, either within the muscle or via the nervous system, to insure that ATP concentrations do not fall too low."

May or may not be true. Again, if by "rigor" you mean contracture or "cramps", then they are observed in healthy people all the time, and typically attributed to electrolyte imbalance. It is quite likely that a certain proportion of "cramps" that are observed in exercising individuals may be attributed to insufficient ATP provision for release of the cross bridges. Of course, there is no evidence of this, but there is also no evidence against it, so, in the context of this discussion, it seems to be appropriate to include.

MY ANSWER:

Muscle cramps occur with increased electrical activity whereas rigor would be electrically silent (as I confirmed by studying a dead body recently - just joking). So I think that cramps are due to a neuromuscular mechanisms whereas rigor is biochemical.

YOU WROTE:

I will agree with this part though:

" so there must be a regulation, either within the muscle or via the nervous system, to insure that ATP concentrations do not fall too low."

MY ANSWER:

Good to have some agreement!!

YOU WROTE:

Finally, the Cheetah argument again appears to be a red herring. Why not use a human example? In fact, didn't you use the Cheetah as an example of thermoregulation and the "CG"? If we put the argument in the context of physiology we are all more familiar with, the 100 m sprinter "fatigues" within a few seconds, if not immediately. Some may go into rigor, some may not, but they don't become glycogen depleted, so, why not? If the pacing strategy is intended for them to complete the bout with energy reserves, why dont' they just run twice as fast and run out of glycogen? Of course, in part it's because ATP utilization is limited by myosin ATPase, and SERCA. It's also because ATP provision is rate limited and as PC stores become depleted, ATP is provided in a much slower fashion. These factors are regulated peripherally, not centrally.

MY ANSWER:

100m sprinting pace falls off only quite late in the sprint so I am not sure that fatigue happens within the first few "seconds".

More to the point though, ATP turnover rate is not really regulated peripherally. The rate of ATP use is set by how many motor units are recruited in the exercising limbs (by the brain). Micromanagement may occur peripherally but the overall rate is set centrally.

In my view sprinting speed is likely regulated to insure that the eccentric load on the hamstring muscles does not exceed their tensile strength. It seems to me that that is the weak point of the sprinter's body.

The point about the Cheetah is simply to take the extreme case of turning on ATP production so rapidly and to show how exquisitely the rate of ATP production and use must be matched. Again I argue that the only way this can really be done is if the extent of muscle recruitment is matched to the muscle's capacity to produce ATP.

Thanks again for your great observations and questions,

Tim Noakes

Tim

quote

"100m sprinting pace falls off only quite late in the sprint so I am not sure that fatigue happens within the first few "seconds".

How much quicker than a human does this occur in a Cheetah?

and

quote

"In my view sprinting speed is likely regulated to insure that the eccentric load on the hamstring muscles does not exceed their tensile strength. It seems to me that that is the weak point of the sprinter's body."

I think it can be a common point of weakness but not for every athlete. Some have a weakness in the calf or the achilles or the plantar fascia. Most often these are related directly to some minor problem in the spine. Hamstrings are probably the best causally linked to the spine by the physiotherapy profession but the whole body links are well known in chiro and osteo as well as many massage therapies especially Shiatsu.

In the 80s i saw a lot of athletes with enhanced strength and it looked pretty obvious that not all the strength was being applied into running. Some wasted time there. Now i realise that mechanical efficiency is more important in that event than actual cross sectional size of muscle and that quality of muscle is important as opposed to quantity. Maybe mechanical efficiency is more important in every event. How much difference can be accounted for in long distance races due to physiological factors. What if Lance Armstrong only had a VO2max of 60, how much less performed would he be (bad example with cycling though). Say a runner like Pre, i heard he had a high VO2max. Have studies on this been done?

thanks

sim

Jack Daniels countered the problem of runners being beaten by others with a lower VO2max by creating the "VDOT" measurement. According to JD, it's a measurement of both VO2max and mechanical efficiency. The benefit of it is that you don't need to know either one to calculate VDOT once you have tables of other athletes' performances and their respective VO2max and efficiency.

i don't understand how efficiency is calculated as it seems to me there are hundreds of variables involved and every athlete has a different balance of these variables. I'm looking at the tables right now and it appears the VDOT is simply based on what time you can do for a particular distance. Is this an incorrect assessment?

What little I know about efficiency is better explained here:http://home.hia.no/~stephens/effiperf.htmEfficiency is a measure of how much of the energy you consume is turned into mechanical work. (Versus economy which measures how much of that energy consumption turns into a desired velocity).Mechanical work can be measured with an ergometer, while energy consumption can be measured indirectly by oxygen consumption. Efficiency then is calculated using these two measures.I found Daniels's solution of using VDOT tables (a product of VO2max and efficiency), and speaking in terms of a pseudo-VO2max, an elegant way to factor out the variability of an athletes performance versus their measured VO2max. It also eliminates the need to measure VO2max, making it more convenient. It's much more practical to obtain a recent race performance, then perform VO2max measurements.But the keen or cynical observer may note that doing so, essentially factors out the relevance of VO2max from determining performance. Although we can probably come up with a list of 10 or so (100?) factors which affect efficiency, some trainable and some not, and the concept may be quite valid in other contexts, it still seems to contain a fudge factor whose purpose is to make VO2max make more sense. VDOT tables are essentially pace-based, and any connection between pseudo and real VO2max almost seems artificial or forced.

sim wrote:

i don't understand how efficiency is calculated as it seems to me there are hundreds of variables involved and every athlete has a different balance of these variables. I'm looking at the tables right now and it appears the VDOT is simply based on what time you can do for a particular distance. Is this an incorrect assessment?

Cheers light!

Would there not be information about efficiency when comparing a persons VO2 max and their result based VDOT?

Also thanks for the distinction between efficiency and economy. I guess i was thinking economy. Possibly it is difficult to determine how much is lost to either in a given situation?

sim

So efficiency is how our effectively our energetic system function whereas economy is how our mechanical or structural system functions. One is microscopic the other macro. Or does efficiency also include structural factors like the heart, lungs, diaphragm as well?

Of course. Daniels's pseudo-VO2max is essentially the product of VO2max and efficiency, so having two of the variables, VO2max and VDOT, you can solve the equation to determine efficiency.The VDOT tables provides a convenient way of not having to worry individually about VO2max or efficiency, which many athletes may not really want to get into, if they just want a lookup table with "optimal" training paces and the resulting improved times.Determining what you lose where is just a question of what you can measure, or estimate with formulas.Cheers,

sim wrote:

Cheers light!

Would there not be information about efficiency when comparing a persons VO2 max and their result based VDOT?

Also thanks for the distinction between efficiency and economy. I guess i was thinking economy. Possibly it is difficult to determine how much is lost to either in a given situation?

sim

I hate to say too much (but can't help it sometimes)-- I gave the link which pretty much summarizes more than I know on the subject, and I often confuse the two or use them interchangeably.However, if you want me to interpret that link, I think the distinction is just where you stop measuring, and what units you end up in.You can be highly efficient (low heat production, efficient energy production), and still have trouble converting that to speed (too much unwanted mass, high wind or water drag, poor technique, wasted lateral or vertical motion, etc.)I don't know about micro- or macro-scopic, but I think of economy as just going one step further -- how much of the mechanical energy produced (determined by efficiency) is actually moving you forward? Structural factors like length of limbs, mass distribution, and total mass affect economy, while the overhead of beating the heart, pumping the blood, and breathing, which consume energy, is a tax on efficiency.However, I'm open to corrections in interpretations (this time).Regards,

sim wrote:

So efficiency is how our effectively our energetic system function whereas economy is how our mechanical or structural system functions. One is microscopic the other macro. Or does efficiency also include structural factors like the heart, lungs, diaphragm as well?

[quote]The Light wrote:

"Mechanical work can be measured with an ergometer, while energy consumption can be measured indirectly by oxygen consumption. Efficiency then is calculated using these two measures."

Exactly, economy is measured as oxygen consumed relative to velocity (meters/second or km/hr) or power (Watts or Joules)!

Efficiency can be measured by heat units relative to work performed, if I remember my science course correctly. A little help from anyone who is well versed on efficiency would be great!

Tim,

As always, I appreciate your response. I am embarrassed to say it to a workaholic such as yourself, but right now I am swamped and need to take care of things, but I will get back to you on this. It will take a bit of time though.

Thanks again.

Steve

To both you and Sim,

Short on time, but...

I wouldn't put a whole lot of stock in using Vdot in conjunction with VO2max for anything. There would be a lot of hand waving. Don't get me wrong, the Vdot tables are great for loosy goosy determination of starting levels etc, but they're 1) not as exact as something like the Mercier tables and 2) differences in the way/place VO2max may be determined, would likely be too variable to get anything of value regarding economy, certainly not efficiency. You can't get "efficiency" from running speed.

Steve

I recall reading somewhere that somewhere on the order of 90-95% of the energy we burn is given off as heat.

However, it's hard to determine how much energy makes us go "forward" because it's hard to define "forward." For example, we expend a LOT of energy just to stay level(not bounce too high, and not let our legs buckle when we land). Only some of a footstrike's force is directed backwards; most of it is downward. There's a million different economic considerations, but the easiest way to factor most of them in is an ergometer, where you can plot the amount of work done against the volume of oxygen consumed.

However, as you point out, this does not take into account many of the running-specific factors in efficiency. I am not aware of any way to measure the amount of work done by a runner at a given speed.

seven 7s wrote:

[quote]The Light wrote:

we expend a LOT of energy just to stay level(not bounce too high, and not let our legs buckle when we land). Only some of a footstrike's force is directed backwards; most of it is downward. There's a million different economic considerations, but the easiest way to factor most of them in is an ergometer, where you can plot the amount of work done against the volume of oxygen consumed.

However, as you point out, this does not take into account many of the running-specific factors in efficiency. I am not aware of any way to measure the amount of work done by a runner at a given speed.

The area of track i like the most or maybe have the most affinity with is probably mechanics and the product of good mechanics is mechanical efficiency. Possibly this is the missing factor that isn't so easily measurable using physiological factors. One test i have done a few times is to sprint over a force platform. We also hurdled over one as well. The biomechanists then provided us with stats on each. The stats basically consisted of downward force, braking force, propelling force, and how quickly each came on.

At top speed the braking and propelling forces were roughly even with slightly more propelling force as it had to overcome ground friction and air resistance.

At any steady pace i think this is the situation - not just top speed. So at a sub-max steady pace say running at LT there are braking forces occurring on each stride as well as propelling forces. Less braking forces would mean less propelling force required to maintain that constant pace.

Mechanics training to make the movement of the body and limbs more efficient ultimately leads to minimising the braking forces for me.

sim

ps as most of the energy is used to maintain position in a downward direction as you say 7s it would also make it reasonable that the more easily you can stand up or stay up whilst running the less one spends in this area as well.

Thanks Steve,You're right. I didn't and I don't. I only answered from a "theoretical" perspective, and of course, I should have corrected the question and said "economy" -- pretty embarrassing since I was trying to make that distinction.My own idea of my VO2max is based on race predictions and a HR test from my Polar watch -- I'm aware of all the caveats there.

Steve McGregor wrote:

To both you and Sim,

Short on time, but...

I wouldn't put a whole lot of stock in using Vdot in conjunction with VO2max for anything. There would be a lot of hand waving. Don't get me wrong, the Vdot tables are great for loosy goosy determination of starting levels etc, but they're 1) not as exact as something like the Mercier tables and 2) differences in the way/place VO2max may be determined, would likely be too variable to get anything of value regarding economy, certainly not efficiency. You can't get "efficiency" from running speed.

Steve

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All the performance tables I have read predict performance on the basis of performance at another distance. This is the most accurate predictor of performance. The use of VO2max and VDOT data is a sleight of hand to give physiological credibility (gravitas) to what should really be accepted for what it is - ie performance at one distance predicts performance at another distance. I discussed this at length in Lore of Running.

Also as argued earlier the reason why VO2max is a relatively weak predictor of performance in athletes with similar running performance is because the real predictor of performance is the peak treadmill speed achieved during the VO2max test. If you are an economical runner your VO2max at that peak velocity will be lower than that of an uneconomical runner at the same peak treadmill velocity. But since the peak velocities they achieved in the VO2 max test is the same, the runners performances will be similar despite often quite large differences in VO2max that can be up to 30%. Again I presented this evidence in Lore of Running.

The reason why no one believes this is because they "know" that the more oxygen you can deliver to your muscles, the faster you will run. Originally this observation that the peak treadmill speed and not the VO2max was the better predictor of running performance put the idea in my head that perhaps it is something other than oxygen delivery to muscle that determines exercise performance. This then led to the gradual development of the CG hypothesis over an initial period of 15 years (1981 - 1996) with continual refinement over the past 12 years.