Supertraining

--- In [EMAIL PROTECTED], [EMAIL PROTECTED] wrote:
>
> I am sorry for latest contribution in my mouse seems to have
wandered
> beyond my intentions, but then, it shows an explorative mind or
maybe it
> is just an Ubermaus.
>
> Maybe my Double Dutch wasn't clear enough, I did not ask anybody to
define
> the term, it was "let's",  a gentle proposal, not a question or
demand.
>
> Until now, nobody has been close to a proper definition, e.g. is
CNS to be
> distinguished from the periferical nervous system or from the
autonomic
> nervous system, isn't the hormonal system with the hypothalamus and
> pituitary part of, or controlled by CNS?
> A few questions to challenge our brains, (at least it challenges
mine)
> Is chronic fatigue syndrome also CNS fatigue?
> Is CNS fatigue the same as CNS tiredness?
> Is CNS fatigue the same as mental fatigue or
> is CNS fatigue lack of motivation(drive)

*********
The below information may add to the discussion:

Medicine & Science in Sports & Exercise: Volume 36(5) Supplement May
2004 p S45
Overtraining and the Neuroendocrine System
Meeusen, Romain FACSM
Vrije Universiteit Brussel, Brussels, Belgium.
0310

The human body has the capacity to adapt to various forms of
stressful stimuli. From a physiological standpoint, exercise can
impose a significant amount of stress on an organism. Muscular
activity requires coordinated integration of many physiological and
biochemical systems. Such integration is possible only if the body's
various tissues and systems can communicate with each other. The
nervous system is responsible for most of this communication through
central command and peripheral adjustements.

The endocrine and nervous system work in concert to initiate and
control movement and all physiological processes it involves. When
all facets of the central nervous and neuroendocrine system are
performing in harmony, the ability to coordinate and regulate key
physiological and metabolic functions, under the perturbations
imposed by physical exercise, is quite remarkable. Regular exercise
or training will result in better performance, however
this 'challenge of homeostasis' can lead to a disturbed balance
between training and recovery.

In overtrained athletes, several signs and symptoms have been
associated with this imbalance between training and recovery.
However, reliable diagnostic markers for distinguishing between well-
trained, overreached and overtrained athletes are lacking. A hallmark
feature of overtraining syndrome (OTS) is the inability to sustain
intense exercise and recover for the next training or competition
session. The symptoms associated with overtraining, such as changes
in emotional behaviour, sleep disturbances, and hormonal dysfunctions
are indicative of changes in the regulation and coordinative function
of the hypothalamus. In pathological situations such as in major
depression and also in overtraining, the glucocorticoids and the
brain monoaminergic systems apparently fail to restrain the
Hypothalamic Pituitary Adrenal axis (HPA) response to stress.
To date, relatively little attention has been placed on the role of
the central nervous system in overtraining and fatigue during
exercise and training. We will focus on the the role of
neurotransmitters and neuromodulators in mechanisms that underly
overtraining.

===========
J Neurol Sci 2000 Mar 15;174(2):92-9

Neuromuscular disturbance outlasts other symptoms of exercise-induced
muscle damage.

Deschenes MR, Brewer RE, Bush JA, McCoy RW, Volek JS, Kraemer WJ.

This study examined the biochemical, immunological, functional, and
neuromuscular responses associated with exercise-induced muscle
damage in the quadriceps of untrained men.

Muscle damage and soreness was elicited with maximal
concentric/eccentric muscle actions at 0.53 rads s(-1). Significant
(P<0.05) soreness was evident 1, 2, and 3 days following muscle
insult, while plasma creatine kinase, a marker of muscle damage, was
elevated 3 and 5 days post-insult. Plasma interleukin-Ibeta was
significantly increased within 5 min, and remained elevated 1, 2, 5,
and 7 days post-insult.

Maximal isometric quadriceps function was impaired (P<0. 05) for 5
days following muscle challenge. Maximal isokinetic performance at
1.09 rads s(-1) was diminished (P<0.05) for 2 days post-insult; no
significant decrements at 3.14 rads s(-1) were noted. Average
electrical activation (iEMG) of the quadriceps was unaltered, but
iEMG activity of the rectus femoris - where soreness was focused -
was significantly increased. Neuromuscular efficiency (torque/iEMG)
was compromised throughout the 10-day post-insult period
investigated. While other symptoms of exercise-induced muscle damage
dissipate within 7 days, neuromuscular perturbation persists for at
least 10 days.

============
Ken Jakalski wrote:

Dr. Hornby mentioned Doug Stuart, one of the top researchers in the field who 
organized a symposium back in 1994 on the issues of central vs. peripheral 
muscle fatigue. This symposium resulted in a book which came out in 1995: 
Fatigue: Neural and Muscular Mechanism, by S.C. Gandevia, et. al.

Although ten years old, this book is still one of the best resources to date on 
muscle fatigue

Regarding the central issue of CNS fatigue, there are indeed central mechanisms 
which account for fatigue, and ample evidence of this in the literature.
What we know is that the electromyographic signal from a muscle during a 
sustained maximal contraction decreases somewhat proportionally to the force 
during the contraction, so there is something that is decreasing the drive to 
them motor neuron or motor pool. Dr. Hornby mentioned that there are three 
central physiological mechanisms that may account for this decreased drive:

1) chemical and mechanical stimuli from a contracting muscle can be sensed by 
different sensory fibers, and this in turn might inhibit the discharge of motor 
units. This appears to have a protective effect on the muscle.
2) When contraction occurs, the drive to motor the neurons which innervate 
sensory stretch receptors (gamma motoneurons) decreases, and this decreases the 
sensory input to the motor pool. Dr. Hornby referred to this as disfacilitation.
3) If you stimulate a motor neuron or its axons directly, the discharge rate of 
the fibers will decrease, without any input from the muscle (i.e., there is an 
intrinsic adaptation of the motor unit discharge). The decrease in discharge 
rate is greater in the fast vs. slow motor units.

Sounds good…and technical… but what about recovery, which is at the heart 
of all our discussions. According to Dr. Hornby, this depends on the task 
performed, and it's difficult to separate out the effect of peripheral 
mechanisms vs. central mechanisms, even more so if the stimuli from a 
contracting muscle can indeed be sensed by different sensory fibers.

In addition, there are supraspinal effects, which means that brain pathways 
that activate the spinal motor pools can adapt their rate of firing as well. 
Evidence of this can be found in Gandevia's book.

As Dr. Hornby notes, " There are also motivational factors, arousal, sense of 
effects, and pharmacological agents that can alter fatigue"

============
>From a recent review of a Charlie Francis seminar:

The CNS is like a cup.
The best way I can relate my understanding of the CNS is that it is
like a cup. You never want it to overflow! This means you should
always play it safe. You are better to slightly under train than over
train. Supercompensation may not be as great but it will still be ok.
Never go for the great super workout as the best possible outcome
from it is a return to normal. There is no need to see the ultimate
levels of an athlete in training.

The volume of each training session needs to be managed at the time.
If there is an extraordinary speed session you may need to drop
weights altogether as including the weight session may cause the cup
to overflow thereby stalling, or even regressing progress.
Progression is vital. If it is a high CNS day you adjust the volume
as required to reach the appropriate CNS limit, conversely if the day
is low CNS ensure it stays that way. Never have back to back high CNS
days.

Whatever you add in to your training you have to take something out,
so if you want to start doing arm curls what are you going to take
out?

============

Loren Chiu also previously noted on the Supertraining list:

…..Regarding neural fatigue, perhaps the two major structures in the
CNS which are of interest regarding exercise and training are the
hypothalamus, which regulates homeostasis and the pituitary gland
which secretes hormones, many of which have a primary function of
signalling release of other hormones.  These hormones include the
anabolic-androgenic hormones, estrogens, thyroid and related
hormones.  So in theory training can (temporarily) negatively affect
the CNS - in practice it appears to be more likely when training
volume is considerably high and during prolonged periods of high
volume training.  This may account for the comments regarding
powerlifters not appearing to suffer from CNS fatigue - the volume of
training in powerlifting is relatively low, compared to sports such
as weightlifting as well as all "endurance sports."

We should not, however, forget the PNS and control of muscular
activity.  With strenuous resistance exercise protocols, either high-
or low-frequency fatigue occurs for durations as long as a week.
Thus planning brief but frequent periods of recovery-type training is
imperative.  For more regarding this, see the recent articles of
Plisk & Stone, and Chiu & Barnes in the latest Strength and
Conditioning Journal (December 2003).

==================
Jamie Carruthers
Wakefield, UK