Charlie identified the concept of CNS Fatigue years ago and gained evidence of its existance through the construction of such a successful training approach ,but can’t we just help each other define the whole thing better ?

Is CNS fatigue a single factor phenomenon linked to a single system in the body (the Central nervous system)?
Does our organism allow for such an isolated phenomenon really?
Or maybe by CNS Fatigue we identify a much more comprehensive concept,which links a number of bodily systems and functions together?

depletion of neurotransmiters is my guess. The neurotransmiter that is responcible for the motor neuron signaling is achetylcholin, which up to a point would become depleted.

obviously, its not that easy to pin point one thing, given the fact the the brain works with so many neurotransmiters acting on so many types of receptors that is nigh imposible to have an absolute definition. But in the end, neurotransmiter depletion and/or receptor descentization and quite likely reuptake receptors upregulation would contribute to CNS fatigue.

basicaly you might want to excecute a certain task but cant. Mind you the CNS fatigue is there among other things to prevent total PNS failure which would be well…death presumably?

that would be the answer i gave at the previous thread

I would go with CNS Fatigue is a comprehensive concept,which links a number of bodily systems and functions together e.g., endocrine, muscular systems etc. neuroendocrine, muscle-nerve.

Don’t forget the peripheral nervous system also.

Sounds like the right idea. Maybe it can be referred to as those factors that take time, beyond that which can be explained purely by muscular recovery, to generate an equivalent or higher performance than was seen in the causal session.

It must be a comprehensive set of factors.

What’s your take on your initial post, pakewi?

Anyone going to take a stab at a definition??

Physiology being my weakest area of knowledge, I can’t speculate specifically but i believe we are talking about a disbalance in several factors (there could be a number of different combinations that lead to the same end results) that limit the body’s ability to produce high rates of force development. As mentioned above, these factors appear to be unrelated to structural damage in muslce fibres.

So in short it is probably a disturbance in homostasis among several non structural body systems that can occur in a variety of ratios.

Perhaps the inverse question is something that we could look at. Under what conditions is the body optimally prepared to produce high rates of force development? Following this we can then consider how these conditions could vary after a period of high intensity training and hence isolate what are the limiting factors (or perhaps downstream limiting factors) in the equation that are not structural in nature?

To follow the lines of the threads above to start off some discussion, I think CNS fatigue is NOT really relate to neurotrasmitters per se,and might well be related more to structural or functional damage in muscular system…
Being a very complex topic,is trying to dissect the possible components the easiest way to try and proceed?

Very interesting, pakewi!
Are you suggesting that specific distractions in the periphery potentially affect the CNS in a negative way making it, therefore, a two-way path? And further, you believe that this has more of an influence on CNS?

PS thanks for bringing this up again, Charlie!

Two questions …

Is there such a concept as ‘PNS fatigue’?

What your interpretation of the relationship bewteen CNS fatgiue and Adrenal fatigue?

Yes from working with OW you must have pretty good idea of the relationship beteen Adrenal, ANS and CNS fatigue.

As for damage at the muscular level, a question for those with more understanding of physiology… During high power sport what damage is done to the muscles and nerves? E.g. what damage do you do during shot putt/weightlifting/sprinting the 100m in 9.77? How is this different to the damage done when running 10x100m at 75% with 50m walk between reps?

These are from notes I had written some time ago on my interpretations and understanding of CNS fatgiue.

I wanted to develop a computer program that could assess to some degree the various degrees of CNS stress on the organism regardless of event/training stimulus.

I have spoken to a number of neurologists informally and to be honest I was just met with blank stares when I started to discuss athletic demands.

Just assessing the components of stress on the whole body - muscular and neural - for a minute …

The 3 key factors I was using were/are …

Engagement - the degree of neural recruitment of the organism as a whole
Intensity - the degree of force expressed
Density - the degree of force divided by the total time of expression and rest

There is also IMO
Factor X - A % factor representing the state of the organism.

This must be inlcuded to take account of nutritonal status, personal mindset, (for amateurs - work stress), personal life demands etc., adrenal effeceincy, of course percived fatigue/energy status or CNS fatigue and can include or be measured/estimated using a simple subjective questionaire test.

This factor X is intersting. Does it follow the fresher the organism the higher the CNS fatigue created by a one off bout can be? How do you find the cumulative effect of CNS fatigue. Does each additional maximal attempt create a lower level of CNS fatigue because you are not fresh? Is there a point where you are so fatigued that you can’t produce CNS stress.

Ok before I keep digging a hole for myself - I am no expert - these are just my theories from my limited ameteur expereinces and readings on the whole CNS concept!!!
I’m sure Charlie and the others will be able to find big errors in my hypotheses!
But here they are for discussion anyway …

These are my thoughts …

“CNS fatigue is a gradual reduction in the effeciency of elements of the nervous system such as the Spinal Cord, cerebelum, parasympathetic system, midbrain and diencephalon.”

“It appears gradual - in that as the fatigue progresses the reduction in operation progresses.”

For example -
The degree of fatigue will affect the athlete gradually - fine motor control my start to diminsh and then gross motor control.
I would speculate that with extreme CNS fatigue taste, hearing and visual systems would be affected negatively.
However since we deal mostly with athleets we never expereince that degree of fatigue since we would expect a breakdown (injury) before reaching that stage.

“CNS stress is concurrent - the various componenst of the CNS seem to be affected simulataneously - but from an athletic perspective to varying degrees.”

Different elements of the CNS diminish slowly, some at greater degrees than others. In other words all elements will be affected slowly and gradually.

“Certain substances can permit both an extenstion of CNS effeciency and a heightening of CNS control.”

By the way I’mnot talking about dark arts here - caffiene is one such supp

“With use of such substances there will always be a debt or price to be paid as the body recovers.”

“Supplements cannot directly restore CNS”

“Adrenal fatigue increases the rate of and speed of CNS fatigue”

“Rest is the single best method of restoring the CNS”

“Supplements can only ever assist in clearing the way for neurotransmitter regeneration, speeding neurotransmitter operation.”

Post physical exertion the organism (including CNS) must recover, massage, lympathic drainage, PWO recovery foods etc will speed muscluar recovery (ie physcial recovery) and therefore reduce the overall stress on the organism permitting CNS regeneration.

Does it follow the fresher the organism the higher the CNS fatigue created by a one off bout can be?
(I would be happier letting Charlie, PJ or Pakewi answer here)
If your talking about a 100m max effort - I would answer yes - as the various factors listed can be used to the maximum.
Also the higher the grade of athlete the greater the CNS fatigue I think.

How do you find the cumulative effect of CNS fatigue.
Well this is the problem - how do you measure CNS fatigue first of all?
Do you use tap-tests or Omega wave?
Like I say I was working on a very basic set of heursitics at the begining of the year so I could balance and monitor CNS fatigue (in weights sessions and running) for a footballer.
I think you can get to a certain level of measurement but - it got to the stage where it became more work that the sessions!
But personally - I do think there may be potential in using such a system to design training programs.

Does each additional maximal attempt create a lower level of CNS fatigue because you are not fresh?
Certainly that would be my perception.

Is there a point where you are so fatigued that you can’t produce CNS stress.
No - I think that other factors would come into play - injury!
CNS fatigue would lead to reduced concentration, redcued propricetion and thus at extreme stress -injury.

Great post No23, but you explain CNS fatigue only for chemical concept of nervous system.

CNS fatigue isn’t only CNS fatigue…sorry if I play with the words!

Neurotransmitters are sure important, but NERVOUS SYSTEM FATIGUE is a more extensive concept, other structure play a major role in this event.

Muscles, Fascia, Chinese Meridians, Acupoint/Trigger Point, Biomagnetism/Bioelectricity, these structure have a great influence on nervous system fatigue and regeneration/recovery.

With omega wave analysis there are more interesting links!

No - not at all.

I think we will both have difficulty explaining ourselves!!!
(And English is supposed to be my “first” language - though Charlie has caught me out a few times!)

Perhaps I gave the impresssion that I believe neurotransmitters are solely the cause of CNS fatigue - I don’t far from it.


Yes other structures play a vital role - but the end result is deterioration of the effeinecy of the CNS at the cerebrum.

Also I consider CNS fatigue a ‘syndrome’ or ‘phenomenom’ rather than an exact symptom if that makes sense?

In other words there are many ways to kill the golden goose.

I agree with the above statement - true - but only in a general sense or as an overall comment.

For example -
Do Trigger Points directly affect the CNS or NS or is it the effects of the resultant hypertonicity, reduced cell hydration, drainage etc and following consequent factors that have a cumulative affect on it?

As I understand it if these elements are not functioning properly there is an increased CNS effect.

Yes with Omega wave there seems to be another area of investigation - Sadly I don’t have access to Omega wave - or fully understand its potential.

No23, Trigger Point can have a direct and indirect effect on CNS/NS.

Leave me explain this concept.

Myofascial trigger points generally are associated only to a muscle problems (direct effect), but there are many reflex (I call it Prioritary Trigger Point), that have a great influence (indirect) on principal body system i.e. cardiac, respiratory, hormonal, digestive.

When you work and release these points (generally local injection or electro/vibrational therapy are the winning choice) You have a modification of a biological profile (found by omega wave).
Ditto for Acupoint.

Autonomic Nervous System has a great influence on CNS (brain), and trigger point/acupoint can influence ANS through myofascial imbalances (bioelectricity?) and some muscles have a major role in these event.

“End Event” (neurotransmitter imbalance) is only the point of the iceberg.


Interesting - thanks - I’m going to have a look at this.

Have you a few references for me Jamirok?

Especially in relation to Prioritary Trigger Points?
Travel and Simmons?

Very interesting conversations. How specifically do trigger points change the ANS? What does release of it do to the PQRS points?