PP 67 : ENDORPHIN PARADOX



The relationship between sporting performance,  endorphins and other neural
biochemicals may be one of the least useful or most useful issues in sports
training today.

Many of the psychological benefits of endurance exercise are invariably
attributed to the secretion of endorphins, enkephalins or other pleasure
chemicals (a la the early work by James Olds on the 'pain and pleasure
centres' in the central nervous system) in the brain.  Addiction to exercise
is also attributed to the same endogenous morphines or peptides, since an
injured athlete often apparently experiences withdrawal symptoms akin to
those experienced by drug addicts undergoing therapy.

Others have also suggested that some of the effects of meditation, central
nervous electrostimulation and various visualisation regimes may be
attributed to the release of such chemicals in the central nervous system. 

Research into cerebellar processes also indicates that this region of the
brain is not only implicated in controlling aspects of movement, but seems to
have areas which are associated with emotion and feeling.  This apparent
association between motion and emotion might then
suggest that movement alone may elicit a generalised pleasure response. 

Now, endorphin (etc) release has been attributed largely to prolonged
endurance exercise, so we have to wonder how this idea relates to the above
comments on possible cerebellar motion-emotion interaction - since movement
alone might stimulate the release of 'pleasure chemicals'!.

We also have to examine empirical evidence from the world of non-endurance
sports, in which strength athletes such as weightlifters, powerlifters and
bodybuilders also tend to display withdrawal symptoms if deprived of training
as a result of injury or other demands.  Does this imply that even the very
short intense epochs of strenuous resistance training also liberate
endorphins in the brain?  Is there any research evidence of this happening or
is this deprivation merely a placebo artefact?

On this theme, then we have to ask if the placebo effect itself could be
explained (at least in part) by the release of  'pleasure chemicals' as part
of some auto-conditioning (operant,  respondent or other) psychological
reinforcement process.

Withdrawal is associated with various responses such as anxiety, pain,
depression and fear, so let us now take another performance-reducing
phenomenon into consideration, namely fatigue. 
Since fatigue (and effort) is heralded by discomfort and pain, some local and
other centralised, would we then be justified in attributing some of the pain
to be the result of impaired or absent endorphin release?

Others might add that there are numerous other neurochemicals, nitrogen
oxides, peptides and even endogenous cannabinoids released in the brain to
mediate control and communication, so that the above propositions are far too
simplistic to warrant a clear answer.  Nevertheless, if we choose just some
of them , one might conjecture a la Timothy Leary that exogenous cannabinoids
(from marijuana), nitrous oxide and morphines are meant to be used in a
'controlled' fashion  to enable the human to evolve neurally to a fuller
experience
of life.  [For those who may not have followed the Leary story, this
psychology professor referred to LSD as a cortical vitamin in his book 'The
Politics of Ecstacy'!].

This is certainly not to suggest in any way that drug abuse is to be approved
of, but it suggests that we should more vigorously investigate the reason why
natural consciousness-modifying substances exist in the body.  After all, it
appears as if the breaking of world sporting records may be becoming more a
function of psychological and neural factors than our rapidly limiting
physical factors. Is it not logical then (within sensible limits of actual
physical damage to the body) that better control of pain and more pleasant
association of any movement or exercise with pleasure should not then lead to
better performance? 

Maybe then we should be investigating the importance of pain control and
pleasure enhancement in sport as potentially one of the major areas for
improving human performance.  Does this perhaps imply that part of the value
of  general heavy resistance training may simply lie in its role in raising
pain thresholds and tolerance and not just in its ability to enhance muscle
hypertrophy and strength?

Exploitation of our endogenous biochemistry, therefore, may allow us to
transcend the current 'barriers' in sport. On the other hand, the tendency of
many sports scientists to relate exercise and  gain in performance, loss of
performance, withdrawal symptoms and so forth to the release of
neurochemicals may be misleading and hasty. 

Comment on these issues and others raised in this series of propositions by
referring to any relevant research or other information that you feel is
important.
_________________________________________________________


PP68: TESTING PARADOX



Inadequate distinction between exercise to FAILURE and exercise to FATIGUE
may be distorting a considerable amount of the testing and measurement of
strength and endurance among athletes.

MUSCULOSKELETAL ISSUES

A great deal of modern technology in Sports Science is devoted to analysing
the muscle strength and endurance, thus:

1.  Maximum strength values or strength/torque curves are obtained  by having
subjects produce as much force or torque as possible against a specific type
of dynamometer (isokinetic ones being the most popular).  The maximum value
read off from the torque/strength curve is then regarded as the peak torque/
strength which the subject can produce for the given movement.

2.  Muscle or local endurance values or torque-time curves are obtained by
having subjects continue to exert effort against a convenient dynamometer 
until they can continue no longer or until the output torque drops to a
certain value.

Some researchers may prefer to carry out similar tests using free weights
exercises such as squats, 'arm curls' or bench press to determine either
maximum strength or muscle endurance.

In this case, it would appear quite clear that maximum strength is exhibited
when the subject cannot execute a single repetition with a given load - he
'fails' in attempting to complete one repetition and the value of the load is
referred to as his 1RM (1 repetition maximum). 'Failure'  to produce greater
performance would undoubtedly appear to be a result of inadequate strength,
rather than inadequate muscle endurance.

Invariably, the point at which failure occurs is regarded to be of no
significance, but is its casual dismissal from the proceedings warranted?  Is
a failure near the beginning of a heavy attempt to be regarded as the same as
a failure near the end of a movement?  Is it not conceivable that what we may
term 'short-term muscle endurance' (high intensity muscle endurance) may be
the more significant limiting factor than inadequate strength?  If this is
true, then this type of testing would be measuring limiting strength and
limiting endurance concurrently and we would not be justified in singling out
either of these possible factors.  As is said in engineering, each factor has
to be regarded as 'indeterminate' and different methods of internal analysis
have to be applied to take the analysis further.

One might then state a preference for isometric testing at a series of
successive joint angles (and sufficient rest time between each reading).  At
least the failure would occur at a given point and a strength-joint angle
curve could be plotted to determine the magnitude of the isometric maximum
force produced and the angle at which this occurs.  However, we could equally
well make out a valid case for the limitations imposed by 'isometric
fatigue', because the isometric force output depends on the time factor.  One
might also point out that slow isometrics and explosive isometrics are
different phenomena.

This brings us to the differences in force production or endurance under
ballistic conditions, in which momentum or stored elastic energy (in tendons
etc) may be used to facilitate maximum force production or continued
repetitions of a given movement.  Are we justified in ignoring the
differences between non-ballistic and ballistic actions in testing, when so
many sporting actions fall into the former category?

For example, the Olympic lifts and the Powerlifts produce very different
strength/power profiles, largely because of the non-ballistic nature of the
powerlifting movements.  How then does one apply isokinetic tests to
determine if a lifter in each of these two lifting sports is deficient in
some musculoskeletal respect and where special training needs to be applied? 
What is the relevance of testing to failure and testing to the point of
fatigue in such cases?

Let us now progress to the situation of sub-maximal or near maximal testing. 
One often comes across tables which show you how to extrapolate to one's 1RM
from one's 3RM (3 rep max) or 6RM, but repetitions to failure with
sub-maximal loads undoubtedly involve an element of high intensity fatigue. 
The physical education realm is strewn with tests of abdominal 'strength'
tests which presume to estimating abdominal strength by having subjects
perform as many situps as possible in a minute or by working to failure. In
this case, there can be little doubt that this type of prolonged test is more
a measure of muscle endurance than strength (1RM), yet use of this test
continues unabated in physical education and sports training.

It would appear that many TESTS TO FAILURE (which are intended to measure
strength) are really TESTS TO FATIGUE and therefore, they fail to give an
unequivocal measure of the maximum strength of a given muscle group (bearing,
in mind, too, that muscles are rarely isolated during any exercise and that a
considerable amount of overflow may occur).  Does this not imply that there
may be great difficulty in separating out the contributions by muscle
strength and endurance factors in all testing?  This is because testing to
failure for a 1RM may implicate resistance to high intensity fatigue and
testing for general endurance may be testing for cardiovascular endurance and
local muscle endurance (resistance to low intensity fatigue).

It is now relevant to examine the possible impact of this P&P on
cardiovascular testing.

CARDIOVASCULAR ISSUES

Of course, our Russian colleagues have for many decades been warning against
the superficial use of treadmills and other ergometers  to assess
cardiovascular endurance, because the work output is a function of both
cardiovascular and local muscle endurance factors.

Already in 1978, the Russian physiologist, Nevmyanov (Principles of
Investigating Work Capacity in Sport  "Teoriya i Praktika Fizischeskoi
Kultury"  1978, 10: 32-37) had written:

"The ability to endure a certain exercise intensity is hardly an indicator of
work capacity.  The influence of the psychological, will-power or
motivational factors here is enormous and is not reflected in popular
biochemical tests.  Nevertheless, it is very rare for exercise physiologists
to take this fundamental factor into consideration when they study work
capacity.  Apparently, the convenience of technological measurement of a few
easily controlled factors deposes the central role played by apparently more
esoteric and difficult-to-measure central nervous and psychological factors".

"Research has shown that the cyclical regularity of running on a treadmill
does not relate functionally to the constant changes of rhythm, pace, stride
length, motor pattern, driving force and direction encountered under actual
sporting conditions.  Although ergometry offers a convenient, controlled way
of analysing human performance, non-functional sports testing can be
misleading in prescribing training and for developing theories in exercise
physiology.  In this respect, the use of dynamometers (isokinetic and other)
to measure the strength of local factors can also be misleading and
counter-productive".

"... Our work has identified several functional indicators which interact and
compensate for deficiencies in one another.  These are primarily indices of
haemodynamics (variations in blood flow volume and deficits in blood flow to
the lower extremities) and these are the most powerful regarding the ability
to compensate for inadequate functioning of other systems.  It is noteworthy
that most physiological studies of endurance do not pay any attention to
limitations imposed by deficits in blood flow to the limbs and other involved
parts of the body.  Conclusions based on measures of general physiological
efficiency such as V02 max and lactate level may then be seen to ignore the
vital role played by local factors in the propulsive and respiratory muscles."

"We deliberately avoid use of the terms 'aerobic' (or oxidative) and
'aerobic' (non-oxidative) work capacity, preferring to speak of indices of
the functional systems involved in work capacity.  In our view, a change in
the conceptual language used in studying work capacity could open new
perspectives for studying the body's capabilities."

It is interesting to note that many Western sports scientists consider that
they are carrying out innovative research into the limitations imposed by
muscular and haemodynamic factors in determining 'cardiovascular performance'
when prolific Russian research in this area dates back more than two decades.
It will be most interesting when more Russian scientists join us on the
Internet to enable us to examine a few more P&Ps in many more areas of Sports
Science (conversely, we trust that they will also gain from our insights).

In summary of this point, Russian scientists have long been warning their
colleagues that ergometer analysis involves the simultaneous and interactive
measurement of several factors, so that we are not justified in
simplistically attributing endurance performance to any single physiological
factor as has been done for ages on treadmills and isokinetic dynamometers
for so long.  Somehow, we need to dig deeper to look at interactions,
compensations and other less obvious factors which determine performance in
each different situation.

CONCLUSION

There would appear to a valid case for trying to distinguish between testing
to failure and testing to fatigue to enable us to re-evaluate the validity of
many of our laboratory tests of human performance. Comment on the issues
presented above, offering suitable references to validate your point of view.
_________________________________________________________


PP 69 : DIURNAL CYCLE PARADOX


Attempts to explain variations in athletic performance and health on  the
basis of specific endogenous rhythms such as a human 25 hour  diurnal cycle
may be misleading and ncorrect.
_____________________________________________________________

Lately, after several decades of indecisive debate, research has been 
renewed regarding the possibility of internal biological rhythms  having a
significant effect on sporting performance, adaptation to  different time
zones, the immune response and miscellaneous  determinants of fitness and
health.

In particular, several researchers have proposed that the  observation that
the human biological day is about 25 hours long and  not 24 hours means that
athletes regularly have to 'catch up' on  a missing hour's sleep and factor
in this effect when crossing time  zones when competing away from home.

Although the 25 hour day is not very well known to the average  athlete, it
has been known for many thousands of years (as the lunar  day) and in more
recent scientific times it has been measured by researchers who isolated
subjects for several months in underground  caves or specially insulated
apartments. Records of urinary hormone rhythms, body temperatures, activity
and so forth showed that most  subjects possess a free-running overall
rhythms of longer than 24 hours. 

Aware that the methods of 'isolation' used in these studies  controlled only
some of the more obvious possible influences such as  light, temperature and
seasonal changes, other scientists examined  the effects of isolating their
subjects from electromagnetic fields  or by changing the intensity of light
in their subterranean chambers (e.g. Aschoff, Poppel & Weever at Max Planck
Inst in Germany).

The subjects in electromagnetic isolation  displayed a cycle period  of 25.26
hours, while those in the unshielded rooms displayed a period  of 24.84 hour.
 When a constant electric field of strength some 1000  times greater than the
ambient fields was introduced into the  shielded rooms, the cycle duration
shortened to 23.5 hours.  The  length of this cycle also decreased as the
intensity of the lighting in  the room was increased.  Justifiably it must be
asked if the 25 hour  day measured is more characteristic of the Northern
Hemisphere  subjects used in most of the studies.  How would the results have
 differed if the subjects had been born and bred in more tropical and 
sunnier climes?

Whatever the relevance of these studies, it is apparent that the 24  hour
solar day used to measure our work and training days does not  accurately
describe our biological timing, which is influenced by  changes in light,
darkness,  electromagnetic fields and other environmental factors.  But are
we justified in simply deposing  the 24 hour solar day and enthroning a 25
hour biological day on  the basis of these studies?

Most studies have concluded that we have an inherent circadian  oscillator
system that can be entrained to any cycles between 23 to  28 hours, but not
to cycles which fall outside this range.  Social  cues also can have a
significant effect on these cycles.

Other scientists have examined the apparent rhythms of REM sleep 
(paradoxical or dream sleep), slow wave sleep and so forth,  sometimes
measuring the variations in secretion of growth hormone,  melatonin and other
hormones.  Some of this work has resulted in the  use of  melatonin
supplementation to help travelling athletes  accommodate more rapidly to new
time zones.  More cautious scientists  have urged conservatism in the
premature use of a hormone whose  systemic long-term effects are not yet
understood, especially since  some subjects find that melatonin can cause
prolonged drowsiness and  fatigue.

It is interesting that the 25 hour daily cycle is not only limited to  human
mammals, but to many other species.  It is possible more  interesting that
this cycle is close to the lunar cycle, which has  led to some scientists
(not unscientific astrologers!) examining if our longer rhythm is being
electromagnetically entrained by lunar  activity and modified by flares in
solar activity (which have long  been shown to affect growth in plants and
major changes in weather).

The controversial father of this work was Dr F Brown (Biological  Clocks 
1962;  The Rhythmic Nature of Animals & Plants  AMERICAN  SCIENTIST XLVII
1959, 2: 164 etc), who concluded that there was also  a very strong case for
exogenous entrainment of biological activity  and not just the primacy of
simple deterministic internal clocks.

His work and that of others also showed that the 25 hour circadian rhythm 
sometimes switched to slower or faster rhythms and then returned to  their
original value.  This we may link to the subject of a previous  P&P, namely
that of the phenomenon of  'Chaos' and partial  indeterminacy - and suggest
that the 25 hour rhythm needs to be  understood in the light of physiological
or cosmic 'chaos' before it  is applied simplistically and erroneously.

After all, other work has shown that blood levels of tryptophan,  tyrosine
and glycogen seem to follow a 24 hour cycle.  Why would some  biochemicals
follow a 24 hour day and others a 25 hour day?  Which  ones tend to dominate
in sporting and physical activity, if any?

Early studies by Halberg et al (Physiologic Twenty-Four Hour  Rhythms in
MAN'S DEPENDENCE ON THE EARTHLY  ATMOSPHERE  Macmillan, 1962) found a 24 hour
rhythm in the rate  at which cells synthesise DNA and RNA, with DNA activity
reaching a  peak as RNA activity is dropping to its nadir.  Later studies
have  revealed similar patterns.  Curiouser and curiouser!

Then there is the issue of psychological time versus clock time, which  can
have a profound effect on performance, as is being revealed by  research into
the effects of stress into the estimation of time, the  immune response,
healing rates and so on.  One would then have to ask  which of a short
psychological day or a 25 hour biological day would  have more profound
implications on sporting performance and training.

In this respect, is it the altered perception of time (and endogenous 
chemical profile)  produced by visualisation , meditation or  other altered
state procedures which modifies performance or is it  the direct effect of
the procedure concerned?  Which is the hen and  which is the chicken?   After
all, the ability to consciously  manipulate one's perception of time and
events in time can have a  major effect in improving performance, especially
in events where  skill and speed are pre-eminent.

For those who are concerned about the validity of the different 
periodisation models, it is interesting to consider the possible 
complicating effects that may be introduced into apparently  meticulously
computed periodisation charts by 25 hour rhythms,  environmental modulators
and self-induced altered state rhythms  (chronically practised by TaiChi and
other Eastern masters).

Comment on the relevance of the 25 hour 'rhythm' and the various 
propositions discussed above, drawing upon any relevant research or 
practical experience.
____________________________________________________________