A significant proportion of the results obtained by certain rehabilitation or
training regimes may be due more to a placebo effect than direct
physiological intervention.
BACKGROUND
Recently there has been considerable discussion about the superiority of one
training or rehabilitation regime over another, with personality clashes and
subjective prejudice periodically clouding the real issues. Most of the
arguments have revolved around showing why one set of experiments and
academic references is more valid than another, or why one's personal
success stories with certain clients should be taken seriously. The former
approach has often met with criticism of academics having little hands-on
experience, while the academicians have retorted that the latter approach is
anecdotal and scientifically uncontrolled.
The fact remains that some apparently outrageous methods with little
apparent scientific validity seem to work, whereas others with impressive
scientific credentials enjoy only limited success. On the other hand, it
invariably happens that the same methods do not work in certain instances,
no matter how scientifically valid and clinically supported. We all know
that some methods work some of the time, but no methods work all of the
time. We all have suffered failure with our most favoured approaches at
some stage as another and we have invoked cognitive dissonance to enable
us to come to temporary terms with our apparent limitations.
Sometimes we teach certain methods to our students and when our protÈgÈs
report back that these are not as successful as we had claimed, we
automatically conclude that our academic offspring must be doing
'something wrong'. All too often we fail to include ourselves or our clients
into the equation, even though we will see later that herein may lie many of
the answers to this paradox.
THE PLOT THICKENS
Then, like a red rag to a bull, someone makes a statement like: "PNF is not
as good as it's made out to be", "No gain without pain", "HIT (High
Intensity
Training) is a waste of time", "Olympic lifting is dangerous",
"plyometric
training is unsafe and counterproductive", "Swiss (Physio) Ball training is
seriously overrated", "Carbo-loading is a waste of time", "Squats are
bad for
the knees", "Rotator Cuff exercises are a waste of effort", "Machine
training
is of limited value", "It worked for him and he was national champion!!",
"My sit-up technique is more scientific than yours!", "My postural
realignment method is better than any other!", "My aerobic Spinning class
doesn't work me as well as swimming" or "Weight training makes me stiff
and muscle-bound". Inevitably, someone who will disagree with every one
of these statements, sometimes on scientific grounds, sometimes on the basis
of practical experience, sometimes on no grounds other than pure emotion!
Why? Just because they are being plain stupid or cussid? Maybe, but
sometimes your critic is of sound and intelligent mind. What then? Are you
willing to accept that you have been wrong for all those years? Hardly!
Imagine abandoning plyometrics, your Spinning bike, your physio ball, your
ab machine, your carefully periodised training program, your favourite
abdominal routine, your Alexander technique, your McConnell regimes,
your Maitland mobes, your deep transverse frictions, your very life blood!
At worst you may be willing to concede that you may need to modify your
former rigidity of approach in some cases or accept that all methods may
work, 'just depending on the situation'.
ENTER THE PLACEBO EFFECT
If so, you simply may be joining the fashionable ranks of those who deem to
call themselves holistic or eclectic On the other hand, it may be that many
methods may enjoy success with some client in the hands of some
professional somewhere at some time or another. As we are well aware, one
of the explanations behind this individual and seemingly irrational response
is the placebo effect (faith factor), which deems that faith in the giver,
the
receiver and the method can cause real change, even though the method has
no proven scientific validity.
Can it be that the placebo effect, a belief in a given method or the person
who applies it is a major player in producing the results that appear in so
many peer-reviewed journals or are sold by fitness or therapeutic
professionals? How can this be? After all, it would appear that the
scientific controls in all of those experiments have been meticulously
applied and statistically analysed.
On the other hand, how often have we read through an article in which the
possible influence of psychological factors definitely has been excluded
from the training or rehabilitation setup being analysed? How often has the
clinician or trainer been excluded from the experimental scene, so that
his/her presence does not skew the results? After all, we know that the mere
presence of a training partner or spectators generally inspires one to
greater
heights.
If the possibility is not mentioned of psychological factors influencing
results, we must then conclude that the experimenters or other professionals
concerned consider such factors to be insignificant or irrelevant. This is
tantamount to maintaining that psychological factors play no major role in
determining sporting results. One might retort that sporting competition is
different and has no bearing on how the average person responds to
rehabilitation or general training. Only the most naÔve would seriously
believe in such a remark.
THE PLACEBO AND SCIENCE
The efficacy of the placebo effect in many medical situations is well
supported by research, as is the effect of little rituals used religiously by
some sports competitors. Many motivational techniques strongly exploit the
placebo effect, which appears in many guises in inspiring or cajoling people
to producing their finest efforts. The 'Power of the Mind' has been extolled
for almost the entire recorded history of human performance (or lack of it).
Many have grown extremely rich or extremely ill as a consequence of it.
Yet, 'objective' science may often be excluding it from the proceedings
without paying adequate attention to it.
The placebo effect may bear not only positive effects, but also negative
ones. Sometimes, the negative placebo effect is known as the nocebo (from
the Latin 'nocere' meaning 'to harm'). In this form, client expectations
that
something may be harmful result in negative effects.
The placebo situation is typified by five standard elements: a problem, a
receiver of an intervention, a giver of the intervention, an explanation of
the
problem and intervention, and the intervention ritual. If the receiver
accepts
a given intervention that is explained plausibly on the basis of his existing
belief system by a believable interventionist using a reinforcing ritual,
then
the placebo effect has a strong chance of being highly effective.
Conversely, if the receiver is skeptical of the intervention, the ritual, the
explanation offered or the credibility of the interventionist, then the
placebo
effect will be minimised. If the receiver entertains any strongly negative
thoughts about any of these placebo elements, then the nocebo effect may
dominate and the intervention may produce negative results.
Moreover, a placebo operates more effectively when offered after some
intervention that has already produced some positive effects. So, if one
uses
a well-tested method which shows definite results, then a subsequent new
method is more likely to succeed than if it was tried raw. Even some well-
chosen words, a introductory ritual offered during the initial consultation
and an inspiring presentation by a credible professional can create the
circumstances for other placebo effects to be invoked with a higher
likelihood of success.
PLACEBOS IN RESEARCH AND TRAINING?
Let us apply this to the experimental situation. The painstaking scientist
will admit that in every experiment involving humans there is the possibility
of distortion by placebo or related psychological factors, but will add that
this is why a large sample of subjects is necessary. Not only are there many
individual variations, but also many different psychological factors (e.g.
personality, placebo effects and behavioural characteristics) which can cast
doubts on the validity of experiments with a few subjects. So, the careful
scientist chooses large, apparently well-matched samples which should
ensure that the individual idiosyncrasies will balance out. Positive placebo
effects should then cancel out negative placebo effects, unmotivated
subjects should cancel out the highly motivated and so forth. Is such an
assumption fully justified? Furthermore, can we ignore any possible
influence by the experimenter, since the latter is really objective and
isolated from the proceedings?
A similar situation concerns all therapeutic measures and training schedules.
Is it not possible that method A works better in the hands of its 'creator'
than
with anyone else? Is it not possible that inspiring words or mere touches of
a credible interventionist are just as responsible for the success of a given
intervention as the intervention itself?
Some research has shown that a significant proportion of the benefits
produced by cardiovascular training are due to a placebo effect generated by
the expectations of subjects who are constantly bombarded by proclamations
that cardiovascular training has positive effects on health and quality of
life.
Brain research has shown that a considerable number of meditators really
just doze off periodically and thereby derive the benefits of 'cat-napping',
so
that some regimes of relaxation, visualisation and meditation may work
more for the placebo reasons of belief in the intervention than the
intervention itself.
PERIODISATION AND PLACEBOS?
Whew! Does this then suggest that the placebo effect may explain why
periodisation (or HIT or any other single form of training) works for some
and not for others? Does the periodic decrease in intensity and/or volume of
loading just make the athlete 'feel more relaxed' and therefore, more willing
to train harder? Does the change in training routine simply serve as a
variation placebo which results in enhanced motivation? Does the
occasional emphasis on 1RMs just serve to boost the ego and feelings of
self-worth of the athlete, thereby serving as a very effective positive
reinforcer (or placebo)? Are the psychological benefits of cyclical
periodisation more influential than its direct physiological effects? Is it
possible to test this hypothesis readily?
CONCLUSION
Possibly this P&P suggests that the placebo effect can override or increase
the known physiological effectiveness of virtually any form of training or
rehabilitation and that the 'power of the mind' should not be excluded from
research or training situations. Maybe a particular training or
rehabilitation
method is only as effective as its committed user. Maybe a huge proportion
of all scientific research to date has to re-examine its validity in the
light of
its possible distortion by psychological factors.
What do you think? Comment on the many issues raised above, drawing
from existing research or your own experience.
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PP111 : MUSCLE TENSION & HYPERTROPHY PARADOX
Magnitude and duration of muscle tension during training may not offer an
adequate explanation for the promotion of hypertrophy.
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It is very common to encounter research and practical advice which
identify a certain minimum level of muscle tension and a certain
duration (e.g. the Tension Time Index) below which any training
regime will offer inadequate increase in muscle bulk.
In other words, one has to train with sufficiently long sets at a
certain percentage of one's 1 Rep Max (1RM) at a certain cadence
and for a certain minimum number of repetitions if one is to produce
hypertrophy. As growth in strength and muscle bulk occurs, so these
minimum values tend to increase, especially regarding the intensity
(% of 1RM or the average weight that you are using in a workout).
It is also common to come across information which states that
isometric training tends to increase strength in the general region
around a certain joint angle, but it does little to promote
hypertrophy.
Now, this is where a problem arises. If one performs a maximal or near
maximal (circa-maximal) isometric contraction and holds it for a
sufficiently long period (e.g. as long as the average dynamic set of
8-10 RMs), for a few sets at different joint angles, then this would
appear to comply with both the minimum tension and the minimum
tension time requirements for hypertrophy. Why then does this
method appear to offer relatively poor hypertrophy, while it still
manages to increase in strength?
Remember, too, that one generally can achieve greater levels of
muscle tension during isometric action compared with concentric
action, so that isometrics of sufficient duration per rep and set
should then offer better hypertrophy training than concentrics
('positives' in bodybuilding jargon).
This might then lead some to deduce that the other remaining
form of muscle action, namely eccentrics, will offer the best
hypertrophy of all, since one can apparently develop the greatest
level of muscle tension during eccentric action. Others might argue
that one cannot resist heavy eccentric loading for long enough to
fulfill the tension time criterion. So, where does that leave us?
Does all of this imply a corollary to the hypertrophy theorem,
namely that we have to add that significant hypertrophy will occur
only if the training activity is dynamic? Thus, it does not matter
what the magnitude or duration of the muscle tension is, hypertrophy
will be minimal unless the exercise involves a certain proportion of
concentric and/or eccentric activity.
To implicate another confounding issue, some weightlifters certainly
do manage to hypertrophy with training regimes using low repetition
sets of brief explosive exercises which do not fulfill the tension
time criterion.
Does this imply that current research and training information on
hypertrophy methods is incomplete and misleading? Or has something
been left out of this P&P which would reconcile all the apparent
contradictions?
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PP113 : PLANNED OVERLOAD PARADOX
The concept of planned overload in training may be inaccurate and
misunderstood.
One of the first principles of physical training learned by every newcomer to
the world of fitness is 'The Gradual Overload Principle', where use of the
word 'overload' means the increase of the current training load over the
previous load. The principle simply means that, to make progress, one
constantly has to train harder by doing more than before. Load, duration,
speed, height, distance or complexity cannot remain the same; the relevant
one (sometimes more) of these measures has to be increased regularly One
has to 'overload' or stress the body so that it can exceed one's best
previous training levels and thereby move to even better competition
performances.
This process is theorised to produce superadaptation or supercompensation,
which means that training at or close to one's maximum causes the body to
over-adapt in some way, so that it next time (or somewhere a little later) a
delayed training effect is caused which allows the body to handle more than
it previously could. For some not entirely clear reason, the body is
programmed to adapt to a higher level of coping by training at a sufficiently
high percentage of one's existing best.
In the engineering realm, this is tantamount to a bridge or other structure
automatically increasing its strength according to the load placed on it.
Unfortunately, man-made structures do not behave like that, so engineers
always 'over design' a structure to cope with stresses which are
significantly higher than those ever anticipated under the most demanding
conditions. Thus, each structure or machine is built with a certain 'safety
factor' or number of times stronger that structure is than the maximum
anticipated loads in daily usage. This is a very sensible approach,
especially in cases such as building construction in earthquake zones or
where wind or water loading is likely to be great.
The human body, however, is not made like that. Apparently, a dynamic sort
of 'safety factor' is endowed upon the body if it is exposed to near maximal
stress in some way or another. Conversely, it deteriorates to a weaker state
if not exposed to a certain regular minimal stress - though it does not
'infra-compensate' (or does it??) to a state below existing baseline if it is
NOT regularly stressed to some minimum level. In simple terms, we usually
state:"If you don't use it, you lose it".
Before we continue with the overload issue, mabe it is worthwhile to take a
detour and consider the possibility that the body may 'infracompensate', a
process characterised by the body dropping in capability below its former
'homeostatic' state if not adequately stressed.
Thus, at either end of the stressing scale, a body stressed near its maximum
will supercompensate to greater strengths and a body not adequately (how
much is adequate?) stressed will drop even further below its existing state.
In this context, we have to ask the questions: "How much stress is enough to
prevent loss of baseline capabilities?" and "How much stress is enough to
produce supercompensation?". Related to all of this is the question: "How
much stress is enough to maintain existing sporting form?".
Now, let us return to the concept of 'overload'. This word literally means
to load something to a level beyond what it is designed to handle. How
correct or appropriate is it to apply such a term to physical training?
Logically speaking, if we overload the body, it will stress it beyond its
existing limits and cause damage or deterioration, which obvioulsy should
lower its capabilities until it repairs itself again. If we argue that the
word 'overload' should be loosely applied to mean the periodic increase in
submaximal loads (if it were maximal, the next load would be supra-maximal,
which is an impossibility), then we have to wonder how it is possible for
significantly submaximal loading to lead to supercompensation beyond one's
existing maximum.
Yet this is precisely what we seem to have been taught for many years, namely
that gradual increase in submaximal training loads somehow causes the body to
supercompensate to higher levels of performance. Of course, in some sports
(like weightlifting, track & field and swimming), one may often train at or
very close to one's training maximum and we know that this can certainly
cause us to superadapt to exceed our current maximum. On the other hand,
training models such as those of periodisation deliberately cycle training
stresses at light, medium and high intensity levels, so that athletes quite
infrequently train at their existing maxima - yet this cyclical
loading-underloading process somehow produces superadaptation to new maxima.
Consider examples from the world of sport. A weightlifter might squat or
clean a submaximal weight of 150kg for several weeks, generally performing
between 1-3 repetitions. He very occasionally might try his 1RM of 160kg at
this stage of training, yet after a few weeks, he finds that his 1RM max has
suddenly jumped to 170 kg. Likewise, a sprinter does sets of 10.9 second
100m sprints for some weeks, occasional attempts to reach his best of 10.4
secs, then, lo and behold, a few weeks later he achieves a new best of
10.3secs.
All of us are very familiar with this phenomenon - in fact, those of us who
are competitive athletes EXPECT this to happen. Yet, we rarely pause
seriously to ask how this submaximal training stimulates one to transcend
one's existing maximum.
All of this seems to suggest that there may be something illogical and
contradictory about the entire concept of 'overloading' and supercompensation
via the theories currently being used to explain adaptation in sport. Do you
agree? Is it illogical to talk about imposing a training 'overload' on the
body to promote superadaptation?
Is it logical to accept unquestioningly that periodic training at or near
one's existing maximum will somehow shift one's maximum to an even higher
level (even though we might argue that generations of athletes have
successfully done so)? How can periodic increases in a submaximal training
load lead to increases in maximum? What determines the ultimate individual
limits of this process? The implications of all of this are multiple.
Why do some athletes respond more rapidly and more powerfully to certain
training loads than others? Do some athletes supercompensate by using
significantly lower submaximal levels than others? Why do some athletes fail
to respond readily to regular work at or near their existing maxima? In
short, do you consider that the existing notions and theories regarding
training overload and adaptation processes need some serious re-examination?
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PP115 : FAILURE & FATIGUE PARADOX
The distinction between failure in single repetition maximum strength
(1RM) due to inherent limitations to strength production and failure due to
short-term fatigue may not be as clearcut as sometimes is believed.
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There has been considerable discussion regarding the role played by
fatigue in determining hypertrophy and the number of repetitions
which can be completed in a given exercise. The relative proportions
of the different types of slow and fast twitch muscle fibres have
been implicated in these discussions, as have the energy sources for
activities of different duration and intensity.
However, it appears that a few questions relating to an earlier P&P
have to be posed again, namely:
Is failure in a 1RM effort in weight training exercises due to
intrinsic limitations within the muscle complex which maintain
certain safety or performance barriers for a given joint action or
exercise? - or is 1RM failure due to very short-term fatigue in the
involved muscle groups?
If we examine the nature of strength (the subject of a topic which I
sent out to this and other groups a few weeks ago), then we may infer
that the inability to lift more than one's current 1RM is due to
limitations in factors such as:
* the total number of muscle fibres that can be activated during
any stage of that exercise
* the force-producing capabilities of the cross-sectional area of the
relevant muscles
* disinhibition of the Golgi-tendon organ processes during increases
in muscle tension towards their current maximum
* the ability of short-term high energy phosphates to deliver
sufficient energy (this may well be regarded as a form of fatigue)
* the excitation threshold of the nerve fibres supplying the relevant
muscles
* the rate of contraction of the relevant muscle fibres
There are several other instrinsic factors (which Dr Verkhoshansky
and I detail in our textbook 'Supertraining' 1996 Ch 1), but the above
few suffice to discuss the issues raised in this P&P.
Are we justified in regarding such 'intrinsic' limiting factors as
being entirely separate from fatigue processes or is there an element
of certain fatigue decrements in performance operating in each of the
above cases (and in any other factors which one may list)?
Distinction certainly is made between central fatigue and peripheral
fatigue, where the former relates to central nervous factors ouside
the muscle output system, whereas the latter refers to fatigue
factors in the peripheral- and neuro-muscular systems, but is this
adequate to allow us to distinguish between failure in a short-term
1RM event and failure in a longer duration event?
Even then, we need to distinguish between very-short term 1RM events
such as the Olympic lift (snatch, clean & jerk) and the longer short-term
events such as the powerlifts (squats, bench presses and deadlifts).
The difference between these short events and the bodybuilding sets
to failure events would appear to be a clear case of peripheral
fatigue for bodybuilders - though, of course, central nervous events
involving loss of motivation, impaired recruitment of spinal motor
neurons and impaired transmission of spinal nerve impulses might also
be involved.
Does the latter example suggest that it may be artificial to
distinguish between 'pure' central fatigue and peripheral fatigue,
when it may be that both classes of fatigue are involved to different
extents in every physical activity?
If we take the whole issue down to the cellular level, fatigue may affect
one or more of the many excitation-contraction processes which begin
with depolarisation of the muscle cell at the neuromuscular junction,
and end with the mechanical power output. Disturbance at any stage
of this chain of events will lower the capability of the muscle cell for
realising its maximum force potential. The primary peripheral sites
which have been implicated in muscle cell fatigue include the motor
end-plate, the sarcolemma, the T-tubules, the sarcoplasmic reticulum and
contractile proteins.
Consequently, would it be preferable to regard all forms of performance
failure as some form of fatigue, rather than as a manifestation of some or
other intrinsic performance barriers?
Over to you.
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