Monday, May 18, 2009

Developing British Rowing Technique

Developing British Rowing Technique
ARA Sep 07
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Thursday, May 14, 2009

Romanian Model of Talent Identification and Promotion


FISA Coaches Conference 2001 Bucharest Romania

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Premises

In Romania, sport certainly belongs to the national culture. Elite sport used to be and still is considered an important means of expression, a virtue and a token of national pride.

At the Summer Olympic Games of the last decades, Romania achieved quite good results, being ranked 13th according to an OG all time unofficial classification.

At the last edition of the Olympic Games in Sydney 2000 with 26 medals (11 Gold, 6 silver, and 9 bronze), Romania was ranked 11th in the world.

Out of these, 3 gold medals were won by the feminine rowers. Please consider that this result made our country be the first in rowing in these Olympics!

This is why this model was selected for today’s presentation.

Our position on the identification of talents and selection in female rowing

The repeated successes of Romanian feminine rowing were also a consequence of an appropriate selection system.

To remain competitive in world confrontations, steps must be taken to extend the area of selection system.

In our view, we think favorable to perform a post-puberty identification, in a period of life when most of the morph, functional and psychological indicators are settled.

The selection models are continuously analyzed in parallel with the best women rowers in the world.

Selection criterions

In the first stage of selection, we choose to work with the help of the following criterions:

The health condition
The functional state of the body
The physical (motric) capacity
The psychological capacity
The somatic development and state of nutrition

3.1 The health condition

The condition of health, is an eliminatory criterion, at all stages of the section, in two typical situation:
- If it is dangerous for the anatomic integrity or even the athletes life
- If is becomes a performance limitation factor

3.2 The functional state of the body

Here we would be interested in the global functional integrity (endocrine, metabolic, hemetalogical, (heart) cardio-respiratory). Practically we are aware that the cardio-respiratory system would most easily adapt to physical strain.

The initial exam should possibly also contain the following functional tests:

- Pashon-Martinet test
- Astrand test
- Spirometry – vital capacity measurement

3.3 The physical capacity (motric capacity)

The internal and external factors have a life long action on physical capacity. The main qualities necessary for the performance rowers are:

- The endurance, cardio-respiratory resistance to long term efforts
- Local muscular resistance in force regime
- Mobility of the coxofemural and talo-crural articulation
- The skill (sense of equilibration and coordination of arms and legs)

3.4. The psychological capacity

The success in rowing is determined as well by the level of development of the traces to reflect the psychological and neuroendocrine profile.

The psychological qualities of future rowers should be dominated by strong will, expressed by perseverance and determination

Also, important is the adaptability to monotonous, often repeated activities as well as the conscientiousness to struggle to come as close to perfection as possible.

3.5 The somatic development and state of nutrition

The somatic development and state of nutrition have always been important criterion in rowing. Here is the evolution of the main selection models for the women in rowing and some consideration concerning them.

3.5.1 The Indicator of Segmentary Ability (I.S.A)

Dr O Popescu elaborated this indicator in the decade 1965-1975. The indicator wad established by taking into consideration six dimensions, four unperfectible and two perfectible ones, namely

3.5.1.1 Stretched height (face to the wall, heels to the floor, arms up over the head)
3.5.1.2 Arms amplitude (face to the wall, stretched at shoulder level)
3.5.1.3 Trunk Height (sitting position, back to the wall, to shoulder level)
3.5.1.4 Legs length (sitting position, back to the wall, feet plant in 90 degrees, to the heels)
3.5.1.5 Bideltiodian diameter (shoulders width)
3.5.1.6 Crouching surplus mobility

Much attention is paid to the perfectible dimensions, imposed by short rails and rowing technique suggesting the balance of the trunk in attack and offcome.

3.5.2 The Rowers Morphological Indicator “R.M.I.” Romanian “I.M.Ca”

This indicator was worked out by Prof C Radut and became operational in the years 1975-1980. The indicator was based on seven measurements, out of which four were unperfectible and three perfectible. The third perfectible dimension was added to the O. Popescu model and was namely:

3.5.2.7 The rowing specific amplitude (crouching surplus mobility + leg length) R.M.I. = The sum of the seven measurements in cm, (the higher the total sum, the more segmentary appropriate is the subject considered for the practice of high performance in rowing)

3.5.3 The Morphological Model

Between 1982-1995 Prof C. Florescu and Prof V. Mociani have proposed an operational model which included 4 measurements, 3 imperfectible and one perfectible:

Height stature
The arms amplitude
Stretched height
The weight

- the value of the model for each parameter taken separately, represent 100%
- The real value of each parameter is transformed in percentage according to the model
- (a+b+c)% / 3 = the value of stature dimension, genetically conditioned and thus perfectible.
- The arithmetic mean is usually calculated expressing in percentage, the relation between the value of dimensions in stature and appreciation of the state nutrition result an integral parameter of physical development.


Mathematically this could be expressed as follows:
(a+b+c) / 3 + d] : 2 = [(98,89 + 98,91 + 101,74) / 2 + 96.15] / 2 = 98%

This model brings in weight, considered by the authors as relevant according to the principle of “mass rows the boat”.

The height appears like another new element, but rather esthetically, as it does not influence considerably rowing movement as one is inclined to think. Could there be a contribution of the necks length and head dimension? This is still to be checked.

The perfectible parameters become less important due to the possible changes in boat construction (like changeable lengths of rails, changing angle of the shoes) as well as the general growth of rowers height.

3.6 Control norms and standard system

The control norms and standard system must be in correlation with the rowing particularity of the effort.

For an initial selection in rowing the following events have been recommended by specialists:

- From stand jump in long
- From stand jump in high
- Horizontal rowing (from facial lie down on a board 4cm thickness, it will suspend at the end to 1m height. The arms stretched keep a 15-20kg dumbbell. The arms bend and stretch for 1 – 4 minutes.
- Genuflection with a dumbbell on the shoulders / relating kg and time
- Trunk abdomen (from lying to sitting position)
- To continue to hang with stretched arms
- To continue to hand with stretch arms
- 1200m to run
- 1000m rowing on ergo
- Equilibrium on a bottle

However, I observe that there is a weak correlation between the results in these initial tests and high performance in the future. If just the quite poor result in the primary and secondary sections achieved by of the best rowers (Elana Horvat Florea, Adriana Cheariu bazon, Doina Ignat, Viorica Susanu, Georgeta Damian, Viorica Susanu, Aurica Chirita) had been taken into consideration, we would have had with four Olympic rowing champions less.

So it is not possible to assert that we are aware of methodology of identification and selection of talens that may satisfy all exigencies. The process of selection remains a desiratum still watching for solution.

The sooner, the better!

The practical revivers selection conclusion from practice.

Selection is an evolving process, essentially relaed to somatic growth, functional and psycho-motor development.

The eliminatory selection system is not the most concluding one.

During the training process after a period of preparations the young debutant rowers, initially unsuitable, can register a remarkable qualitative progress, often taking advantage over those who had been predicted a brilliant sports career.

In principle, a small number of tests are preferable to an overloaded and sophisticated package of tests, which will make selection even more difficult and rather create confusion than enhance degree of certainty.

This is why during the practical identification and selection campaign, operated only with two segmentary measurements: stretched height (over 224cm) and amplitude arms (over 178cm).

This minimal selection model has been confirmed by praxis. It thought us that no young lady should be eliminated who is promising and could in future become an Olympic medalist. As an example please observe the segmentary values of our Golden Ladies at Sydney 2000.

All young female rowers who are healthy, preset minimal segmentary values and wish to practice rowing as a sport, should be admitted to take part in the second phase of selection.

A super motivated athlete can compensate many of the effort or somatic demands.

The mobilization of the available neuro-psychological capacity is directly related to the level of motivation. During the training, the capacity of the young female rowers to become high performance athletes will be achieved.

Ultimately it depends on the “TALENTED” young, promising lady athlete how she manages to coordinate her social activities (school, family, professional) so as to succeed in dedicating rowing the time budget required by more and more demanding and challenging conditions.

Wednesday, April 1, 2009

Applying Biomechanics to Improve Rowing Performance

Applying Biomechanics to Improve Rowing Performance
By Peter Schwanitz (GER)
Translated from German by Lena Baden and Fred Kilgallin
From FISA Coach Vol 2 No 3 Summer 1991
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Editors Note: The following is an abbreviated version of the original presentation by Dr. Peter Schwanitz at the 1990 FISA Coaches Conference in Athens. Dr Schwanitz presents recommendations for improving rowing performance based on research conducted at the former East German Sports Science Centre (FES) in Berlin. His analysis is based in part on parameters obtained from boats equipped with biomechanical measuring devices. His primary measurements are the velocity of the inboard of the oar and the force applied to the inboard of the oar. These are simply means to objectively measure characteristics which are usually subjectively determined by the coach. Dr Schwanitz shares the thought provoking findings of his many tests from the 1980’s in the GDR.

Improvement of Rowing Performance

Every rowing race has a winner. The winner the individual or the crew – has rowed the racing distance in the fastest time with the highest average boat speed. The final performances by rowers in the finals of the top international competitions (World Championships and Olympic Games) are the result of important and complex efforts by the rowers and the coaches.

The results make it possible to evaluate, among other thins, the effectiveness of the training, the creatively efficient effort of the athlete during training and competition, and the development of modern materials for the production of boats, oars, and other equipment. In order t draw conclusions about future success in competitive rowing it is important t to have a general idea of the trends in racing times in the finals of previous top international competitions. If this is regarded as a benchmark for the development of performance requirements in rowing, it is important to emphasize that the performance is influenced by two factors: The human factors (personal abilities, fitness, rowing technique, etc.) and the non-human factors (boat, equipment, weather, regatta course, etc).

Three questions about development of performance will be addressed in this section. The answers to these questions are based on the following:
- the winning times of all boat classes for men in the World Championships and the Olympic Games; and
- The results of test races performed in measuring boats by FES – Berlin in cooperation with Humbolt University in Berlin.

Question 1: How has the race performance (boat speed, racing times) developed?
Figure 1 shows the development of the boats speed of winners of the Olympic finals in all men’s boat classes from 1948 to 1988.


If you analyze the average boat speed of all winners of the men’s Olympic Finals (except the 4x) from 1948 (London) to 1988 (Seoul), it is clear that from one Olympic Games to the next, the average boat speed over the racing distance has increased by 1.3 percent.

It is interesting that the development in the average 1st place time corresponds to the relative development in the single sculls. From this one may cautiously draw conclusions about the development of the individual performance.

If this period of time is divided then (see doted lines in Fig 1) from 1948 (London) to 1968 (Mexico) the first place times in an Olympic cycle improved o average 1.9 percent. Winning times in the period since 1968 have improved at a rate greater than the previous period.

The result is that boat velocity, as a mean value for the Olympic winners of all boat classes has increased on average by 1.9 percent in an Olympic cycle. The relationships in velocity between boat classes (mean values) of the winners have stabilized (see Table 1).


Question 2: How are the racing performances in the Olympic cycles of the 1992 and 1996 likely to develop?

Future increases in speed over 2000m have been calculated based on improvements in performances. It should be noted that weather is included as an “average condition”. Therefore the expected improvement implies “average” weather conditions (i.e. calm, small waves etc). For example, for the three boat classes 1x, 2-, and 8+, the improvement in the racing time and the boat speed in the cycles of 1992 and 1996 are clear in Table 2.


Question 3: How are the key technical parameters likely to change in the cycles 1992 and 1996?

Assuming constant stroke rate in the three selected boat classes, the Olympic winner in 1992 and 1996 will have to:
- educe the total number of strokes in the race
- increase the propulsion per stroke in comparison to the winner of 1998 ad 1992 (see Table 3a and 3b)
Assuming constant propulsion in the three boat classes, stroke rates must increase.

Now it is interesting to see the consequences of the probable quantitative improvement of important rowing technique parameters and their relative percentage changes (see Table 4). These data were obtained from measurements of the former East German National Team.

In the three boat classes the highest percentage rates of increase in the realized average performance (P) on the inboard (PIH) are shown for:
- a rowing cycle (PIHZ)
- The effective drive (PIHEF) in the rowing cycle.

The product of the factors “force on the inboard or inside lever” (FIHEF) and the “velocity of the inboard or inside lever” (VIHEF) with the mechanical performance of the inboard show a minor rate of increase within an Olympic cycle.

In general it should be noted that the increase in boat speed puts demand on the athlete to exert more power on the inboard and to attain a higher velocity on the inboard.

Applying Interdisciplinary Contributions to Improve Performance

The definition of biomechanics can be described as the effects of mechanical laws on and in the living organism and their mechanically measurable reactions of the organism to these effects.

Thus biomechanics has its basis in both the physical and biological sciences. Therefore, one should not depend solely on mechanical findings to determine how to achieve competitive goals, (victory, bets possible result, faster, etc)

This knowledge must be translated for use in interdisciplinary synthesis and an application oriented training plan. The following four questions and their answers attempt to substantiate this claim.

Question 1: What are the possibilities and limitations of the contributions of biomechanics to the sport of rowing?

The essential focus of biomechanics in rowing has and always will be rowing technique

Most objectives of biomechanical research are to explain the propulsion-causing powers and accelerations of the rowing stroke during competitions, both in theory and in practice. This research also tries to explain the effects of the development of equipment.

Theoretically explained biomechanical knowledge and the empirical findings that create successful rowers are the bases for forming a technical concept. The application of the concept has contributed to the improvement of rowing performance.

The biomechanics of athletic movements in the endurance sport of rowing can improve performance, especially if it considers biomechanical/energetic and biological/energetic interactions. The task in this connection is:
- to investigate the movement sequences during competition and training in order to explain those mechanical causes that influence the biological/conditional effects;
- To develop rowing technique as a biomechanical solution process that can be applied to the effective biological/energetic development in training as well as result in higher speed during races.

It is important to develop and identify rowing technique from a biomechanical perspective, which makes it possible for the athlete:
- to achieve the fastest racing times and the highest average boat speed over the rowing distance on the basis of his or her individually available energy potentials at the lowest possible external resistance;
- to achieve the fastest time over a given distance on the basis of his or her individually available biological energy potential and taking into account the biological-conditional objectives for the particular training area at given resistance conditions (boat type, gearing, area of blade, etc.).

Question 2: What research could form the basis for the establishment of a rowing technique for training and competition?

In practice you can find different force-time curves on the oarlock [F=f(t)] with an approximately equal impulse area. These can be classified as shown in Figure 2.



“A” emphasizes the middle of the drive – synchronous force of leg, upper body and arm musculature is dominant. “B” emphasizes the end of the drive – synchronous forces of the upper body and arm musculature is dominant. “C” emphasizes the beginning of the drive – synchronous forces of the leg and upper body musculature is dominant. “D” strongly emphasizes the beginning of the drive with no emphasis on the remainder of the drive.

The strongly schematized force/time curves appear in rowing of all classes, including World and Olympic Champions!

But which of these curves will now be useful? Trying to get the answers from the science of biomechanics alone won’t be enough. The following accounts should give some help in making decisions.

“The work is all the more inefficient the more tension there is in the muscle at the end of the effort, because the work is wasted isometrically, without producing any performance.” (Landois-Rosemann, 1962, p. 504)

“The force/distance curves with a short steep rise to the peak of maximum force and a subsequent flatter fall off the end of the work distance appears to be the most favorable. The effectiveness of the energy turnover for equal work is, in comparison to other curves, the highest, since the necessary energy turnover is the lowest.” (Landois-Rosemann, 1962)

This information disqualifies an orientation towards hard pressure at the finish of the rowing stroke, and it highlights an emphasis on the beginning of the stroke.

“Equal work, realized though extreme tension of the different muscle groups, results in various local loads. The higher loads manifest themselves in the smaller muscle groups (i.e. the legs) and the lower loads in the larger muscle groups (i.e. the legs) (Hollmann/Hettinger, 1976)

From this statement it makes sense to employ a synchronous whole body effort of muscle potentials, taking into account the different force potentials of the leg-, back- and arm muscles. Emphasis on the finish of the stroke should be deemphasized because of the high local load on the arm muscles.

“There are two alternate ways to increase performance (in the mechanical sense, as a product of force and movement velocity): you can increase either the force or the movement velocity. The physiological processes react more strongly to changes in movement velocity than to changes in force.” (Landois-Rosemann, 1962; Roth/Schwanitz/Korner, 1989)

Thus, it makes more sense to improve the time of the movements during the whole drive where the body parts work synchronously. The necessary high velocity on the inboard can be carried out throughout the slower movements of the legs, upper body and arms while they work individually.

“A high force development in the beginning of the rowing stroke seems to be the most effective with regard to the most favorable body position for a proportional development of the force potentials. The position of the body in the beginning of the drive can be compared to the position of a weightlifter at the beginning of the weightlifting process” (Gjessing, 1979)

In light of the previous statement, one should emphasize the beginning of the drive portion of the stroke. Empirical research carried out by this author has produced the following results:
- The average boat speed per stroke rose with the rowers increased force exertion on the inboard at the beginning of the drive;
- The increase in boat speed did not parallel the increase of average force past the 90 degree position of the oar relative to the splashboard;
- The recorded increase of inboard velocity in the area of the drive is therefore mostly a function of higher boat speed initiated by the higher inboard force at the beginning of the drive (Schwanitz, 1975)

Therefore, one can justify an emphasis on the beginning of the drive as well as an orientation towards increasing the force in the middle of the drive and in the finish in order to make use of reserves (Schwanitz, 1976). In the discussion about the effectiveness of the rowing stroke, Nolte (1985) raised the aspect of the hydrodynamic lift, which supports the orientation towards the beginning of the drive.

Summary
From a biomechanical, biological and training-method point of view, there are reasons for an efficient rowing technique that takes into account the aspect of load as well as the propulsive effect during training and competition. The emphasis of the force on the inboard, in order to produce a powerful first part of the drive, characterizes this rowing technique and should be encouraged.

In addition to the emphasis on the first part of the drive, the force on the inboard should be produced in the tangential direction to the inboard, especially before the 90 degree position. A common expression for this force expression should be “row around the oarlock”.

The intention of al training methods is to increase the individual performances in the drive phase. This also covers the common forms of diagnosis used in biomechanics, rowing technique and sports medicine. These usually show the effects of training under defined test conditions.

The increased force exertion and movement velocity as components of the mechanical performance are the correlated partners of the biological and mechanical criteria, with the drive given first priority. Here one should pay attention to the fact that the coordination requirements of the recovery phase are particularly high. In training it is important to carry out a conscious conditioning of the muscles used during the recovery at race intensity to counter conditionally caused coordination problems and to ensure the propulsive effect in the drive by paying special attention to the reversal movement into the entry.

Question 3: What should the coach and athlete know about rowing in different boat classes?

An analysis of training methods with boat measurement technology of FES Berlin in 1978 gave results which later, strengthened the considerations of the rowing federations of the former GDR with regards to decisions about loads. Rowing in different boat types will, under the same training conditions (distance, stroke rate), put different demands on the athlete and result in different loads. A comparative examination of inboard velocities in similar tainting ranges gives the following results:
- Recovery: The profile of the inboard velocity and the time bases approximately match in the various boat classes;
- Drive: As the boat classes get bigger the acceleration on the inboard in the beginning of the stroke increases, and the drive time decreases considerably. (Refer to Table 5.)



Question 4: How does the individual rower deal with the requirements of the specific boat classes?

The research in the biomechanically explained movements of the different boat classes made it possible to qualify the diagnostics of the measurement boats in such a way that that the individual load requirements and effects during training could be clarified, along with the development of rowing technique. This led to an experiment in 1987 carried out by Korner (training methodology), Roth (performance physiology) and Schwanitz (biomechanics).

The object of the experiment was the rower’s mastery of the boat type specific requirements. Four athletes each carried out the following tests in 1x, 2+ and 4+ measuring boats:
- A five step test (one step: three min.);
- one unit of basic endurance training (90min.; stroke rate =20-22)

Inevitably there were the same general requirements (stroke rate, boat velocity) for every step for the four rowers in 4+. However, every rower showed very different realizations of the demands of every load level from the biomechanical point of view. The analysis of the biomechanical parameters shows great dispersion among the rowers at the same load input (between 4 and 25 percent). It was striking that:
- the highest individual deviation in the load steps appeared at lower velocity
- at all load levels the inboard velocity showed the smallest individual deviation, which is mechanically explainable

The overall impression of a team is often formed by that which one can see, such as movements of the body parts relative to each other and to the boat as well as movements of the oars and the boat. In general, one can conclude that:
- The different load demands of each boat class and of each step in the test show very individual results in rowing technique and physiological load.
- In every load of the step test the performance on the inboard as the product of the inboard force and the velocity shows particularly large differences for every rower in all boat classes.
- Performance, force, velocity, lactate and other biological parameters determined as functions of the load in the different boat classes by the same rowers confirm the necessity and the possibility of emphasizing the individual control of performance development my means of biomechanical/rowing technique parameters and characteristics. (See example of this analysis in Fig 4.)

The results of this experiment were used to prepare the athletes of the rowing federation of the former GDR for the 1988 Olympic Games in Seoul. Early in 1988 the women’s sweep rowing team was diagnosed according to this method and given training recommendations, later in June selection tests were carried out to form crews in different boat types.

A basic endurance load test of more than 90minutes at the stroke rate 20-22 showed:
- large differences among rowers in performance, force and velocity on the inboard
- Different amounts of force and velocity among the rowers
- Different lactate concentrations that prevented at least one rower form reaching the biological training goal

As the training progressed all four athletes tended to:
- decrease the inboard velocity during the drive
- increase the inboard velocity during the recovery
- reduce the force on the inboard
- reduce the performance on the inboard during the drive

The following facts can be applied to the examined boat classes:
- depending on the length of time and intensity of the training session on the water, a relatively early tendency of decreased rowing technique was observed;
- The biggest deviations in the technical parameters from rower to rower happened under low intensity training.

These facts strongly support Roth’s demands in 1987 for a transition from methodology/biological training concept to a methodology/biomechanical training concept to improve the performance of the active rowers.

Conclusion

The previous improvements in times and the average boat speed in the finals of top international competition are milestones in the development of rowing performances. They are the result of human factors, developed by training and experience and influenced by non human factors. In terms of Olympic cycles, the relative increases in the average boat speed of 1.5 percent to 2.0 percent are also likely in the future.

The biomechanics of athletic movement based on physical and biological sciences can improve rowing performance, especially in biomechanical/energetic and biological/energetic contexts.

The following two essential tasks should be emphasized:
- the improvement of rowing technique to help the biological/energetic development during training, which leads to a higher boat speed and faster times in competition;
- The examination of movement patterns during competition and training to explain the mechanical causes in biological-conditional effects.

From a biomechanical and biological point, there are reasons for adopting an efficient rowing technique, the most important characteristics of which is the emphasis on the first part of the drive.

In order to perfect the technique and fitness as a synthesis for further improvement in rowing performance, one should find and pay special attention to the specific aspects of each boat class and the individual use of these characteristics.

The conscious use of boat characteristics depends on ones knowledge of rowing in big boats versus small boats. For example, when going from a small boat to a big boat, one experiences:
- reduced drive times;
- increased inboard velocity;
- increased emphasis on the first part of the drive;
- reduced drive-phase proportion in comparison to the whole stroke cycle (changed rhythm relations);
- increased inboard velocity on the performance of the drive

Knowing about the individual characteristics of a certain boat class, one will be able to prescribe the correct work load and gear the athlete in training towards a successful performance.

Diagnostic methods to check certain abilities specific to rowing should allow a variation of the loads that will enable the athlete to reach the limits of his or her current individual ability. It is therefore possible to make low risk assessments of the training effectiveness, and to give recommendations more likely to succeed in the further development of performance.

A diagnosis of the rowing technique should be done along with keeping track of the rowing performance. For this reason it is recommended that you make a system of diagnoses (video analysis, dynamic-graphical measurements, individually or together):
- full stroke cycle and drive portion evaluations;
- competitive evaluations in test and regatta environments;
- Work load evaluations.

Abbreviations
Variables:
P = Performance
F = Force
V = Velocity
T = Time
S = Distance

Indices:
B = Boat
EF = Effective Drive
IH = Inboard part of the oar
FL = Recovery
Z = Rowing Cycle

Example:
PIHZ = average performance (P) on the inboard (IH) of one rowing cycle (Z) in the rowing stroke.

Reference Parameters:
SF = Stroke Rate
GA = Basic Endurance
WSA = Specific Endurance necessary for competition
S = Sprint
WK = Competition

References:
Andrich, B/Buchmann, R/Schwanitz, P: Ansatze fur die Erarbeitung biomechnischer Zweckmassigkeitskriterien sportlicher Bewegungshandlungen in Ausdauersportarten fur Wettkampf und Training. In: Theorie und Praxis der Korperkultur 38(1989) 6, p. 420-422
Gjessing, E: Muskeltatigkeit und Bewegungs verlauf beim Rudern – eine Kraftanalyse. In: FISA Coaches Conference, 1976, p 15-35
Hollanm, W./Hettinger, T.: Sportsmedizin – Arbeits – und Trainings-grundlage. Stutgart, 1980.
Muller: entnomen Landois-Rosemann: Lehrbuch der Physiologie des Menschen. Vol II, Munchen –Berlin, 1962, P 504.
Nolte V.: Die effectivitat des Ruderschlages, Berlin, 1985.
Roth, R./Schwanitz, P./Korer, T.: Untersuchungen zum Freiwasser-Mehr-stufentest in den Messbooten Vierer, Zweier, Einer in funf Geschwindigjeitsstufen. DRSV-intern, Berlin, 1989.
Schwantiz, O.: Ruderspezifische Systembetrachtung und Analyse der Veranderungen Rudertechnischer Parameter in drei Geschwindigkeitsstufen. Dissertation, Humbolt-Universitat in Berlin, 1976.

Force Application during the Drive Phase

Force Application during the Drive Phase
By Valery Kleshnev
Rowing Biomechanics Newsletter No2 Volume 4 February 2004
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… increasing the force faster at catch is very important for achieving efficient rowing technique? Below are force curves (as a ratio to body mass) of two crews, where the crew 1 increases the force much quicker than the crew 2, but crew 1 has relatively lower maximal (7.27 and 8.84 N/kg, correspondingly) and average (3.84 and 4.09 N/kg) force application:

It is also important, that the first crew increases the force by means of faster leg drive, good connection with the trunk work and more horizontal and shallower blade path:

As the consequence, the handle velocity of the first crew increases at catch up to higher value and maintain it longer during the drive:


The boat speed and acceleration curves of the first crew have deeper negative peak at catch (7.6 and 7.1 m/s2), but much quicker increase afterwards.

This creates faster moving support on the stretcher and helps to accelerate rower’s centre of mass (RBN 1/2004):


We can figure out three main reasons of higher efficiency and better performance of the first crew:
- Higher power production due to higher handle speed and in spite of lower force application (4.06 and 3.83 W/kg, 5.6% difference equal to 6s gain over 2000m);
- Lower fluctuations of the boat speed (deviations were 0.70 and 0.72 m/s), which cause higher boat velocity efficiency (98.17% and 97.64%, 2s faster over 2000m);
- Lower inertial losses caused by lower fluctuations of the rower’s CM speed (9.4% and 11.4%, 2s faster over 2000m).

Finally, the overall gain due to better technique of the first crew was approximately 10s over 2000, which was nearly equal to the margin between two crews in the race.

Understanding Gold Medal Standards

Selection – Understanding Gold Medal Standards
By Tom Landry,
Nova Scotia Rowing Association

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What is a Gold Medal Standard?
A Gold Medal Standard (GMS) is the theoretically predicted fastest possible time that a crew of a particular class can race the Olympic distance of 2000 m.

In Canada, The GMS times are developed by Rowing Canada Aviron (RCA) (often the Director of High Performance) based on gold medaling international performances. The GMS times are reflective of what RCA deems a necessary time for a crew to win a gold medal internationally (World Championships and Olympic Games). As international race times improve, GMS times change to reflect advances in training, equipment, and competitiveness. Therefore, the GMS times published by RCA are adjusted often on a four year basis to coincide with the Olympic quadrennial.

Understanding Gold Medal Standards
Currently (2008), The GMS time for a Heavyweight Men’s 8+ is 5:19. That means that if a men’s 8+ can race 2000 m in a time of 5 minutes 19 seconds they should be able to achieve a gold medal performance at the either the World Championships or the Olympic Games.

Similarly, the GMS time for a Lightweight Women’s 2X is 6:45. A lightweight women’s 2X should be able to achieve a gold medal performance internationally if they can race 2000 m in a time of 6 minutes 45 seconds. There are GMS times for every boat class that is raced in international competition. GMS times are often inferred for crews for which there is no international event (e.g. Heavyweight Women’s 4+). Junior GMS times are typically used for Masters.

Gold Medal Standard Percentages
What is most useful in the analysis of performance is not the time a crew rows the 2000 m distance but rather the percentage of Gold Medal Standard time (GMS%) achieved. For example, if a men’s 8+ rows 2000 m in 5:53 we want to know what percentage this time represents of the fastest possible GMS time of 5:19.

A time of 5:53 represents a boat velocity of 5.666 m/s as calculated by:

velocity = distance / time = 2000 m / 353 s = 5.666 m/s

Similarly, the GMS time of 5:19 represents a velocity of 6.269 m/s (the velocity associated with the GMS time is called the prognostic speed). So the GMS% achieved by the crew that rowed 2000 m in 5:53 is given by:

5.666m/s / 6.296m/s = 0.9037 = 90.37%

Why are Gold Medal Standard Percentages Useful?
Class Comparison
In the previous example a men’s 8+ rowed a 2000 distance in 5:53. Imagine now that a lightweight women’s 2X covers the same distance in a time of 6:53. Which is the higher quality crew?

The GMS% achieved by the men’s 8+ is 90.37% (as shown in the example above. The GMS time for the lightweight women’s 2X is 6:45. Following the same calculation above the lightweight women’s 2X GMS% is 98.07%. Despite the fact that the men’s 8+ was a full minute faster, the lightweight women’s 2X is the superior crew. While these crews will never race in competition the lightweight women’s 2X will compete in their event at a much higher level. Class comparison is also useful on an ongoing basis. In a weekly time trial crews can measure how they are performing on a regular basis relative to other crews regardless of class. This can be particularly encouraging for developing crews who improve their GMS% each week compared to experienced crews.

Team Selection
Every regatta represents a slightly different level of competition. Achieving a gold medal performance at World Championships is definitely more difficult than winning a gold medal at a local club regatta. GMS can be used to assess the competitiveness of a crew at any competitive stage of rowing.

Example #1: Cut Off Lines
There are 6 crews of both junior men and women that are interested competing at the Eastern Interprovincial Rowing Championships. The coach selects a distance that is reflective of the race distance at that regatta and evaluates the crews in a time trial format.

The results look like:
Crew 1 88.1%
Crew 3 87.9%
Crew 5 87.8%
Crew 2 86.9&
Crew 4 82.1%
Crew 6 79.9%

Which crews should qualify to go to the regatta? This is not an easy question to answer. First and foremost, the selection committee (or coach) must be aware of the philosophy of the team under selection.

Inclusive Philosophy: The inclusive team philosophy is one in which the selection committee (or coach) intends to send a full team to the regatta regardless of the level of competitiveness of each crew. This can be achieved by starting with Crew 1 and working down the ranking until a full team is achieved. This ensures the best and largest possible team but does not consider the team’s competitiveness.

Competitive Philosophy: If the philosophy of the team is to send only those crews that will be competitive it must first be established what GMS% is reflective of a gold medal performance at that specific regatta. Crews that are then close to this level of performance in the time trial should be considered and those that are not should be cut.

To determine the GMS% that is reflective of a gold medal performance for varying regattas coaches and selection committee members must use their expertise and discretion. Often coaches and the selection committee will base the interpretation of the results on one or two crews that are in the time trial that have previously achieved a high level of success at the regatta. For example, if Crew 3 above were a lightweight men’s 2X that were gold medalist at the same regatta a year ago, it can be inferred that a GMS% of ~88% is reflective of a gold medal performance at that level of competition. If Crew 3 cannot be used as relative performance indicator (perhaps Crew 3 has significantly improved or detrained over the year) coaches and selections committees must use subjective experience to establish what % is reflective if a gold medal performance.

Let’s continue to assume that 88% is reflective of a gold medal performance. If the philosophy of the team is to send only gold medal hopeful crews, Crews 1, 3, and 5 should strongly be considered. If the philosophy of the team is to send crews that will simply be competitive, perhaps top qualifying top 3 or making a final of 6 boats, Crews 1, 3, 5, and 2 should be considered.

You will never remove all subjectivity from team selection procedures. GMS are an excellent way to promote fairness, transparency, and to minimize subjectivity.

Example #2 Improving Your Chances
Often at regattas coaches are faced with the dilemma of two events being very close together and having the same athlete(s) in both races. At some regattas “hot seating” is possible but at higher levels of competition you must choose to focus on only one event. GMS% can be used to determine in which event you are most likely to achieve a higher level of performance.

As an example, a coach has to decide whether to race two masters women in a 2X or to include them in a masters women’s 4X. The scheduling of events at a regatta prevents them from racing both events. If the goal is to achieve the highest level of performance the coach could organize a time trial in practice and obtain a GMS% for both combinations of crews over the race distance to determine which crew is performing at the higher level of competition. If the 2X achieves a GMS% of 83.12% and the 4X achieves a GMS% of 84.91%, the coach should race the 4X at the regatta.

Interestingly the coach could also use GMS% to make the exact opposite decision. How? GMS% can be used to assess the competitiveness of a particular event at the regatta. If for example the masters women’s 4X event that the women are going to enter is extremely competitive with the top six boats finishing within 0.5% of each other year after year the coach might opt instead to enter the masters women’s 2X event for which the crew is, according to GMS%, less competitive. If the master’s women’s 2X event normally only has 3 entries with poor GMS% achieved historically, this might be a great shot at a medal.

Common Pitfalls of Using GMS
GMS% Dependence on Conditions
Gathering on water performance data, such as hosting a weekly time trial or timed pieces in practice, allows you to monitor your progress. However, unlike many sports where performance times are highly reproducible, rowing times are not. Times in rowing are significantly influenced by many factors such as wind, current, water temperature, water
depth, and water composition. These factors change from course to course, day to day, and minute to minute. Since times are highly variable so too are GMS%.

As an example, I have personally measured a change in 500 m splits on Lake Banook of 3-5 seconds from April to November as the water temperature increases. You may improve your 1000 m time by as much as 10 seconds over the season and not really be any faster. The improvements are a result of warmer water and less resistance on your hull.

As another example, coaches cannot compare crews GMS% outside of about a 3-4 minute window. If a crew races a 1000 m time trial and another crew follows immediately afterwards GMS% are comparable. However, if both crews are separated by a substantial amount of time wind conditions can significantly change making a relative comparison useless. You can certainly not compare results from crews given time data collected on different days. Unfortunately, coaches do this all the time.

Misinterpreting the Meaning Behind 1%
It is easy to confuse the significance behind the on water time differential between crews when you consider only the GMS%.

If a heavyweight men’s 1X achieves a GMS% of 94.10% and another heavyweight men’s 1X achieves a GMS% of 91.10% it might be tempting to conclude that they are relatively the same speed. After all, there is only a 3% difference in speed between scullers. But what time differential does that 3% represent. In this case, for a GMS of 6:33 for the men’s 1X, a difference of 3% is equal to a 10 second lead! That is approximately 50 m or 6 boat lengths of open water! 1% GMS is a significant amount of time.

How are Gold Medal Standards used in Nova Scotia?
GMS are used in Nova Scotia by the Nova Scotia Rowing Association (NSRA) as part of the provincial team selection document. Crews that aim to compete for the Nova Scotia Provincial Team at the Canada Summer Games, Eastern Interprovincial Rowing Championships, or the National Rowing Championships will be subject to a time trial and assessed using GMS%. As described above, a selection committee (consisting of a mediator and a representative of each club) will draw a cut off line from GMS% results that result from a time trial conducted by the Provincial Team Coach. The Provincial Team coach is normally responsible to select and nominate crews to the time trial stage but is omitted from the final selection process to promote accountability and to remove coach subjectivity. Athletes are made aware of results in a timely manner and a formal appeals procedure is in place.

Monday, March 2, 2009

Terminology and Differentiation of Training Methods

TERMINOLOGY AND DIFFERENTIATION OF TRAINING METHODS
By Dieter Steinhofer
www.athleticscoaching.ca
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In the following text, based on an abbreviated translation from Leistungssport, Germany, Vol. 26, No. 6, November 1993, the author attempts to improve communication between coaches and scientists by proposing a reconstruction of terminology to be adjusted to training principles and methods based on the required physical performance capacity. The article was originally reprinted from A Collection of European Sports Science Translations, published by the S.A. Sports Institute. Re-printed here with permission from Modern Athlete and Coach.

THE PROBLEM
Everybody interested in the science of training knows that there is a need for a dialogue between theory and practice. The frequent absence of communication between athletes, coaches and sports scientists has been the result of inaccurate terminology and sometimes even contradictions when it comes to the interpretation of training methods. The aim should therefore be to re-construct the methodical training principles, as well as training methods and their characteristics, so that they are based on the required physical capacities.

Such a differentiated new structure is necessary because literature dealing with training sciences refers all conditioning training into four or five basic methods. This allocation is no longer suitable for contemporary specialized training. The training required for all physical capacities is covered in the following basic methods:
The continuous method
The interval method
The repetition method
The competition and control method.

The aforementioned methods of endurance training were, without close examination, transferred to strength, speed, mobility etc. development. This took place even when the methods did not fit into the accepted practical evidence. At the same time the influences of certain training methods were wrongly evaluated, while others were overlooked because they simply didn’t fit into the system.

TRAINING METHODS AND THEIR LOAD COMPONENT
The ‘decisive’ factors of methodical training have multiple determinations. The decisive levels extend, among others, from the concept, the execution, the organization and the external and internal feedbacks of training to the evaluation and interpretation of it. At the same time the planned procedures to achieve the desired training effects are determined by the arrangement of the training contents and means based on the load components:
The load volume.
The load frequency.
The load intensity.
The load duration.
The load density.

These load components allow the determination of the volume, duration, intensity and recoveries for an exercise to be performed (see table 1). The load frequency refers here to daily, weekly and monthly periods and depends largely on an athlete’s training state and performance aims.

The continuous method is characterized by uninterrupted high volume loads with relatively limited load intensities. The extensive and intensive interval methods are based on a pre-planned alteration between loads and recoveries. The loads are adjusted according to the task. A high volume and medium intensity represents intensive interval training.

Decisive, next to the volume and intensity of the load, is the length of recoveries. In contrast to the repetition method, interval training proceeds from incomplete recoveries. The breaks are consciously adjusted to prevent a complete recovery in order to create fatigue.

The repetition method is also based on a pre-planned alteration of loads and recoveries. However, the aim is for complete or nearly complete recoveries between the repetitions (for example, heart rate <>


TRAINING METHODS IN PRACTICE
The division of training methods and their characteristics in the German sport science literature is certainly useful as a systematization attempt. On the other hand, it complicates concrete planning and conduction of training. Some of the following examples will verify this statement.

Endurance Training
A prerequisite for the use of a recommended load is its operational clarity. Load recommendations for the continuous method should therefore clarify their background. For example, what does “limited” or “60% to 80%” really mean? Is the load value based on the best competition performance, on maximal speed (m/s), on maximal heart rate (HR/min.), or on maximal watt performance? All these values are, according to the advice and the training aim, employable. Also the pd-values of Conconi, or lactate values, can be used in the determination of intensities. Whatever the chosen value, it will influence the other norms and together with these will have a training effect.

Interval Training
Difficulties in the determination of load norms apply more so to interval training. What do intensity recommendations mean here? Do the intensity recommendations apply to a single load or to a series of loads? How is the incomplete recovery to be interpreted? What differences apply to the determination of intensities for endurance, strength endurance or speed endurance development in interval training?

The situation is even more difficult in the determination of the load density. How is the incomplete recovery determined? The rule for medium and longer single loads in cyclic activities, that recommends a heart rate of 120 to 130/min. before a new load is applied, can only be valid for short anaerobic loads and never for strength endurance training.

The controversial statements on when the recoveries should be incomplete or complete correspond partly to the obviously confusing statements on training aims. In case interval training is supposed to achieve fatigue accumulation from incomplete recoveries, the aim of interval training should be regarded as the development of resistance to fatigue to improve endurance performance capacity.

Several sport scientists (example, Martin 1997, Letzelter 1978, Weiweck 1983, Letzelter 1986, Martin et al 1991), leaning on the theories of Scholich (1965) and Harre (1968), allocate interval training to the role of the development of speed, power, speed strength and explosive strength. However, a closer look at interval training defined as a method with incomplete recoveries in between single loads, reveals that the recoveries in capacities are in practice rather complete. Letzelter (1978) recommends in his “Intensive interval methods III” 3 to 50 minutes recoveries in the development of explosive strength. Obviously this crosses the border of the repetition method.

The border between interval training and continuous training in the development of endurance is also hard to define. This applies to the duration of the load in interval training. Several authors refer here to short, medium and long interval training, corresponding to 15 seconds to 2 minutes, 2 to 8 minutes and 8 to 15 minutes respectively. The type of stimulus in interval training, based on systematical alterations between work and recovery, is overlooked.

Repetition Training
The main problems in converting the information from the literature on load components for practical application occur in the repetition method. Firstly, it is assumed that this method, based on complete or nearly complete recoveries, has the function of avoiding an accumulation of fatigue, or at least delay it as long as possible. This makes it possible to achieve the training aims requiring high loads (for example, the development of speed, explosive strength, reactive strength, technique). Intensive loads can be repeated frequently after full recoveries. The duration of a full recovery cannot be presented in a time unit, because the recovery interval depends upon the previous load. A full recovery after a highly intensive load of a few seconds can be very short (1 to 2 min.), while a maximal load of 3 min. requires a lot longer for complete recovery (15 to 30 min.).

Information on recovery in time units is therefore not useful in practice. Even more confusing in the repetition method are the given intensity ranges (90 to 100%), sub-maximal, maximal. Whilst high intensities are certainly sensible and necessary for many training means, they can only be repeated after a sufficient recovery interval.

Furthermore, loads of considerably lower intensity in higher volumes also have a place in the repetition method (hypertrophy. coordination). For example, load intensities in hypertrophy training can, according to the aim, range from 50 to 80% in employment of a high number of repetitions and full recoveries between the sets.

In Summary: All training exercises performed with alternating loads and complete recoveries correspond to the principles of the repetition method. Extremely high intensities, sometimes regarded as belonging to this method, are unrealistic for certain tasks and therefore not practical. Intensive training exercises are not as decisive in the repetition method as complete recovery intervals in the prevention of fatigue accumulation.

ALTERNATE STRUCTURAL TENDENCIES
Recent sport science literature questions the here criticized traditional division and characteristics of training methods. Trends towards a different approach can already be found in Weineck’s work (1983) on training methods for the development of endurance, strength and speed. Martin (1991) writes: “The attempted simplification of the training doctrine that divides all methods into the continuous, interval, repetition, competition and control principles cannot be accepted, in view of the known practical possibilities and the number of components that make up a method.” We recommend as a possible solution to arrange training methods based only on their conditioning or coordinative foundation. Grosser et al have chosen a similar arrangement (table 2). Both of the above outlined proposals of structural changes are not convincing for the following reasons:
-The terminology for the different methods is presented at the same comprehension level. The methodical principles (for example, interval and repetition methods) are mixed with concrete methodical measures (for example, strength endurance method, speed-strength method).

-The arrangement of the methods is questionable (for example, the repetition method as a substructure of the interval method).
-The objective is not always correct (for example, the use of intensive interval training for the development of speed).
-The terminology sometimes differs considerably for identifiable methods and is therefore misleading for practical application.

MODIFIED STRUCTURAL CONCEPT
It appears that, because training methods according to their task — development of strength, speed-strength or endurance, have different objectives, it is hardly sensible to arrange the methods based on their typical load components. The repetition method in strength training, for example, has a completely different objective than in endurance training and the load characteristics differ accordingly. From this it appears valid to proceed so that the methodical measures are orientated to practical objectives that are mostly of a complex nature.

The systematic arrangement of training methods in tables 3, 4, 5 can by no means cover the complex training procedures, although it provides an oversight of a large number of combinations and variations. Combined training procedures, mixed formats and modifications occur and become increasingly more important in high performance training. Consequently, the training methods summed up in the table represent only a selection for different training objectives.

The following are some explanatory remarks to the material presented in tables 3,4,5:
The use of the term interval principle can be justified only when we are dealing with endurance, including such complex capacities as strength endurance and speed endurance.
The aim is to accumulate fatigue from incomplete recoveries so that the accumulation does not force the reduction of the load volume.
The temporal classification of short, medium and long intervals loads are used with practical training application in mind. The longer the single interval loads, the less valid becomes the term interval because the training effect will be changed.
The concept of strength endurance is based closely on the definition of Buhrie (1985) and Martin et al. (1991) as the capacity to apply strength impulses in a certain time unit without a reduction of the impulse level. We are dealing with resistance to fatigue at an intensity level of 30% below the maximal. This level and duration of the load corresponds predominantly to the anaerobic lactacid energy supply. Longer and lower strength loads (less than 30% below the maximal) change training into endurance loads under increasing aerobic energy supply and can’t be regarded as strength endurance.
Speed endurance is defined as the capacity to keep speed losses minimal in short speed performances of less than 2 min. at maximal or sub-maximal intensity. Grosser (1991) separates 8 to 12 sec. speed performances (submaximal). Martin et al. defines up to 30 sec. maximal intensity performances as sprint endurance and up to 120 sec. sub-maximal intensity performances as speed endurance. We have for practical reasons, eliminated this division.
Decisive in speed endurance and its sub-classifications is the fact that we are dealing with frequency and high intensity endurance performances where the exact limiting factors are not unequivocally explained.
The repetition principle is suitable for several different conditioning training effects. However, it is assumed that the intensity in repetition training is not based exclusively on high and highest possible loads.

Physiological Training Principles are Often Inaccurate

PHYSIOLOGICAL TRAINING PRINCIPLES ARE OFTEN INACCURATE
Reviewed by Brent Rushall -Coaching Science Abstracts
From Noakes, T. D. (2000). Physiological models to understand exercise fatigue and the adaptations that predict or enhance athletic performance. Scandinavian Journal of Medicine and Science in Sports, 10, 123-145.
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This review article critically evaluates several physiological models (i.e., explanations) that are supposed to account for exercise responses and improvements. Such models are variously used as the theoretical bases for structuring training programs for athletes. A central theme of the review is that contemporary physiology looks at explanations for responding rather than the accurate prediction of performance improvements. The former is relatively secure from critical evaluation whereas the latter is difficult to research and has an inherent possibility of failure.
A second suggestion is that contemporary physiologists have forgotten the history of the discipline. Many informative, substantive, and valuable principles of exercise response were discovered in the first part of the twentieth century but have gradually have fallen out of the common literature. That omission is one of the reasons that contribute to modern theories of exercise physiology being incomplete and inaccurate.

Research Weaknesses
The accurate measurement of exercise responses in the field has been subverted by laboratory testing. The author offers three reasons why this has occurred.

The variables influencing human performance are not easily controlled. A field setting exacerbates that difficulty. This has led to the situation where laboratory measurements are used to infer performance characteristics in the field (e.g., a change in VO2max is used to infer the likelihood of an endurance performance change).

There is a dearth of tools to measure accurately human performance in the laboratory. If sports performance cannot be measured frequently with a high degree of precision in the laboratory, then training-induced changes in sports performance are not quantifiable. Direct, accurate testing is rarely possible. Consequently, physiological surrogates (e.g., VO2peak, VO2) are used to predict changes in performance.

". . . most training studies . . . have measured the physiological and biochemical responses of the human to training and have paid less attention (i) to the extent to which human exercise performance is altered by different training programs and (ii) to the specific physiological adaptations which explain training induced changes in athletic performance." (p. 124)
An important weakness in current exercise physiology is a lack of certain knowledge of the precise factors that determine fatigue and hence, limit performance in different types of exercise under a range of environmental conditions. This is largely due to researchers and teachers advocating only one specific incomplete model of exercise physiology that does not explain performance under all conditions.

The review contemplates five exercise physiology models used popularly to explain and guide physical conditioning programs.

1. The Cardiovascular/anaerobic Model
In maximal exercise, this model holds that endurance performance is determined by the capacity of the heart to pump large volumes of blood and oxygen to muscles. That facilitates muscles achieving higher work rates ("cardiovascular fitness") before outstripping the available oxygen supply ("anaerobiosis"). The capacity of the muscles to use fat as fuel ("aerobic lipolysis") is also increased. This is currently the most popular model for guiding the structure of training programs.

An increase in coronary blood flow that is inherent in this model is largely overlooked. However, the pumping capacity of the heart is restricted and limits oxygen utilization. Since that is so, the heart itself will be the first organ affected by the postulated oxygen deficiency. A. V. Hill's pioneering work has been incorrectly interpreted and an error perpetuated. Hill's actual interpretation of the fatigue that develops during maximal exercise was:

"Certain it is that the capacity of the body for muscular exercise depends largely, if not mainly, on the capacity and output of the heart. It would obviously be very dangerous for the organ to be able, as the skeletal muscle is able, to exhaust itself very completely and rapidly, to take exercise far in excess of its capacity for recovery . . . When the oxygen supply becomes inadequate, it is probable that the heart rapidly beings to diminish its output, so avoiding exhaustion . . . " (Hill et al., 1924)

The heart is a muscle that is subject to the same functional constraints as skeletal muscle -- it needs oxygen to operate. The cardiovascular/anaerobic model ignores the role of the heart and assumes that all muscles fatigue at the same rate, both heart and skeletal. There must be some form of a central "governor" that stops the heart from reaching dangerous levels of fatigue. No such mechanism has been discovered because no one has looked for it.

Peak blood lactate, maximum heart rate, and cardiac output all fall with increases in altitude. At altitude, exercise terminates when exercising muscles are contracting in fully aerobic conditions. Thus, this model is unsatisfactory when it proposes the delivery of an adequate oxygen supply to exercising muscles is the cardinal priority during exercise. Some unexplained mechanism must exist that prevents the heart from becoming anaerobic during maximal exercise at any altitude. Neither skeletal nor cardiac muscles show any evidence for anaerobic metabolism at altitude.

The model is inconsistent when submaximal work is compared to maximal work. Similar function in maximal work must also exist in submaximal work, but at the lesser level, oxygen transport cannot be limiting. For example, a superior capacity for oxygen consumption during maximum exercise does not explain the manifest superiority of Kenyan runners during more prolonged submaximal exercise. Black runners have been shown to run substantially faster at all distances beyond 5 km despite VO2max values that are similar to middle-distance runners. What they did exhibit was a capability to sustain a substantially higher proportion of their VO2max when racing. They have superior fatigue resistance rather than aerobic capacity [%VO2max is a valid measure of fatigue resistance.] A VO2max test does not measure all the physiological variables determining success during more prolonged exercise.

"In summary, there are serious theoretical flaws in the proposed cardiovascular/anaerobic mode of exercise physiology and athletic performance, . . . not least because the model predicts that a "plateau" in cardiac output must develop before skeletal muscle anaerobiosis can begin to occur. But any "plateau" in cardiac output requires that myocardial ischaemia be present either to cause that plateau (according to the theory that anaerobiosis limits muscle function) or as a result of it, as the cardiac output determines both coronary and skeletal muscle blood flow. As myocardial ischaemia has never been shown to develop during maximal exercise in healthy humans, so it would seem unlikely that skeletal muscle anaerobiosis can develop during progressive exercise to exhaustion . . . Rather, it would seem that "fatigue" during maximal exercise of short duration is part of a regulated neural process that prevents the development of myocardial ischaemia during maximal exercise." (p. 132)

Implications. Skeletal muscles do not develop anaerobiosis and form the effect that limits exercise. Some governor that protects the human from destructive fatigue level appears to exist. The functioning of the heart seems to be the important factor in any maximum exercise, and should be the emphasis of training programs.

2. The Energy Supply/Energy Depletion Model
This energy supply model predicts that performance in events of different duration is determined by the capacity to produce energy (ATP) by the separate metabolic pathways including the phosphagens, oxygen-independent glycolysis, aerobic glycolysis, and aerobic lipolysis. Superior performance is explained by a greater capacity to generate ATP in the specific metabolic pathways associated with an activity. For example, a common explanation is that a sprinter has a greater capacity to generate ATP from intramuscular phosphagen stores and oxygen-independent glycolysis, as opposed to a marathon runner who has a superior capacity to oxidize fat (aerobic lipolysis). Its basic tenet is that exercise must cease when ATP depletion occurs.

The status of this model's hypotheses is uncertain, as insufficient substantive research has been conducted. To validate this model's reasoning, the following have to be demonstrated.
The different metabolic pathway capacities need to be causally related to different events.
Specific metabolic pathways adapt specifically to different forms of training.
Adaptations alone explain different performances that result from training exercises of different duration.

Research has shown the following, each of which contradicts the implications of this model.
ATP concentrations in "exhausted" muscles rarely drop below 60% of resting values.
High-energy phosphates do not participate in fatigue, but other factors reduce the use rate of ATP before ATP becomes limiting.

There is a wide range of muscle pH concentrations reached at exhaustion (uniform acidosis is not exhibited across muscles).

ATP demand by contracting muscles never exceeds the maximum rate of ATP supply.
Muscle recovery is related to recovery of muscle phosphocreatine concentrations and unrelated to muscle pH concentrations.

Some peripheral governor needs to exist to account for these observations because acidosis does not play a direct role in fatigue in maximal exercise. Exercise terminates for reasons other than muscular lactacidosis.

Implication. Exercise is not limited by muscles achieving any critical level of acidosis although the availability of intramuscular phosphagen stores is. The contribution of neural factors that intervene with maximum peripheral muscular exercise has to be considered.

The energy depletion model is specific to exercises lasting longer than two hours. It holds that depletion of endogenous carbohydrate (CHO) stores limits the ability to perform long term exercise.

Much research to support this model has been conducted with inadequate or absent controls. Recently, better experimental designs have been used and placebo effects, as well as less consistent results, have been recorded. Additionally, the phenomenon of CHO-loading is not as evident in women as it is in men (it is hard to grasp why there would be a gender difference in biochemical function).

It is virtually impossible to prove conclusively that muscle glycogen depletion alone limits prolonged exercise performance because so many other factors occur concurrently. To support this model, future research has to show that neural factors are not involved (they seem to be involved in the previous two models).

It is unclear how an inability to produce ATP at sufficiently high rates from one fuel source can explain this form of fatigue, given that ATP concentrations in muscles remain high in all forms of exhaustion.

Further contradictory studies have shown that individuals ceased performing in the fourth hour of exercise when their muscle glycogen concentrations were the same as they were at the end of the first hour of exercising.

Huge increases in muscle glycogen concentrations at the start of exercise only have a minimal impact on performance improvement in some subjects.

It has not been shown that training improves endurance performance exclusively by increasing body carbohydrate stores and by delaying the onset of carbohydrate depletion.
Very prolonged exercises (e.g., Ironman triathlons, 100-mile races) oxidize amounts of CHO in volumes that far exceed those existing in the body, without much detriment to performance in their later stages.

The human body is limited in its capacity to store CHO. High rates of CHO oxidation are required to sustain high rates of energy expenditure. Studies of very prolonged exercise show that rates of CHO oxidation remain high in athletes who ingest appropriate CHO during exercise. Because both muscle and liver glycogen depletion occur in fatigue, it is commonly assumed there is a direct causal relationship between muscle glycogen depletion and the development of fatigue in prolonged exercise. However, the relationship might not be causal under all circumstances. There is a logical impasse because any energy depletion model predicts that exercise must terminate when muscle ATP depletion occurs (leading to muscle rigor). Other factors must be involved in causing fatigue in prolonged exercise.

A popular explanation for "sparing" CHO is that with training, the ability to oxidize fats improves and this extends and improves performance without requiring higher CHO utilization. However, that explanation is still inadequate because ultimately it proposes that ATP depletion limits exercise, something that does not occur. This model is too simple to explain the physiology of prolonged exercise.

Implication. The CHO-depletion model does not adequately explain the response to prolonged exercise because at the end of the metabolic chain, ATP is not depleted. Some other reason has to exist for exercising to cease.

This and the previous model "are based on the assumption that it is either the delivery of substrate either in blood (oxygen) or via the glycolytic and oxidative pathways (ATP) that limits exercise performance. The steps of (il)logic that have influenced these assumptions have been described . . . It remains difficult to prove whether or no either of these models is correct. Yet both continue to dominate, perhaps subconsciously, research and teaching in the exercise sciences, often to the exclusion of competing possibilities." (p. 137)

3. The Muscle Recruitment (Central Fatigue)/Muscle Power Model
The fourth model has two parts that imply it is not the rate of supply of substrate (oxygen or fuel) to muscle that limits performance, but rather the processes involved in skeletal muscle recruitment, excitation, and contraction. The concept of central neural fatigue is invoked.
For the muscle recruitment model, the evidence is sufficiently persuasive to believe that central nervous system fatigue contributes to diminished performance in prolonged exercise, at altitude, and in the heat. In no study observing this phenomenon, is there evidence of anaerobiosis or energy depletion. This model also proposes there is a progressive peripheral fatigue for which the central nervous system makes an appropriate adjustment.

The central neural model does not specify important physiological mechanisms to account for fatigue.


Professor Noakes has argued elsewhere that a reduced central activation of exercising muscles is a protective mechanism. It prevents the following states.
-Myocardial ischaemia.
-Muscle ATP depletion.
-Myocardial ischaemia or cerebral hypoxia at altitude.
-A fall in blood pressure.
-Heatstroke.
-Glucopaenic brain damage during states of hypoglycaemia.


The muscle power model proposes that muscle contractile capacity, the ability to generate force, is not the same in the muscles of all humans. Superior athletes have a superior capacity to generate force. Very little has been researched on this alternative. David Costill reported that endurance training reduces skeletal muscle contractility, which shows that muscle contractility is not an immutable characteristic of the different muscle fiber types.

"In summary, these two sub-models . . . predict that changes in exercise performance may result from increased skeletal muscle recruitment resulting from enhanced central neural drive, or from increased muscle contractile function resulting from biochemical adaptations in muscle that increase either force production or rate of sarcomere shortening, or both." (p. 139)
Implication. Performance increases resulting from this model would only occur within the limits of cardiovascular function within the specific activity.

4. The Biomechanical Model
Performance prediction is based on the greater the muscle's capacity to act as a spring, the less torque it must produce and hence, the more efficient it is. An improvement in performance stems from an increase in elastic muscle efficiency. That efficiency results from slowing the:
-Rate of accumulation of metabolites that cause fatigue, and
-The rate of rise in body temperature.

Reaching a core temperature that prevents continuing exercise is delayed.
This model is in direct contrast to the cardiovascular/anaerobic model, which predicts that superior performance during prolonged exercise results from an increased oxygen delivery to muscle and an increased rate of energy, resulting in increased heat production. A more logical assumption would be to reduce the rate of oxygen consumption and heat production by increasing the economy of movement.

Two factors that reduce heat production are small size and superior running economy. The more economical the athlete, the faster he/she will be able to run before reaching a limiting body temperature. Most training studies show that improvements in running/movement economy result from practice. Thus, being more economical, rather than having a higher VO2max, appears to be a more logical approach for explaining enhanced endurance performance.

A second component of this model stems from observations that repeated high velocity, short duration eccentric muscle contractions, as occur during running, induce a specific form of fatigue that lasts for a considerable time after cessation of the fatiguing activity. Characteristics of that fatigue are reduced contractile capacity, reduced tolerance for muscle stretch, and a delayed transfer from muscle stretch to muscle shortening in the stretch-shortening cycle. These result in the duration of a movement cycle being extended. Since these abnormalities last for several days they cannot be explained by oxygen or substrate delivery models.

In summary, the biomechanical model predicts that superior performance, especially in a weight-bearing activity like running, may be influenced by the capacity of the muscles to act as elastic energy return systems.

Implication. This model will demand that recovery be given as much emphasis as overload in training so that muscle function is preserved as long as possible, thereby facilitating the greatest volume of effective training.

5. The Psychological/motivational Model
Any demonstration of an ergogenic effect of any placebo intervention on exercise would prove this model contributes, at least in part, to athletic performance. In the field of physiology, this model is rarely considered. It does have some credibility in sport psychology, as well as emerging support from CHO-loading studies that are beginning to show a placebo effect.
Implication. The structure and content of an athlete's thinking could have an effect on the quality of performance.

Conclusions
". . . until the factors determining both fatigue and athletic performance are established definitely, it remains difficult to define which training adaptations are the most important for enhancing athletic performance, or how training should be structured to maximize those adaptations." (p. 141)

Many findings are incompatible with the predictions of these models. The traditional tenets of physiology should be challenged until universal predictive validity is established.

New interpretations of training structures and content are warranted. The limited reasons and implications from the restrictive models described in this review will not result in the best form of training. The following are implied [training adaptations are considered to be responses that will transfer to competitive performances].

The use of laboratory measurements, which are only partially related to laboratory performance, are useless for predicting competitive performances.

Training programs based on oxygen and substrate supply theories, are likely to result in incorrect stimulation and will not yield maximal fitness adaptation for a specific sport.

Training that emphasizes the reaction of muscles in the replicated activities of the sport is likely to produce beneficial fitness adaptation. [It should be noted that training with auxiliary activities, such as weight training, will not produce adaptations that generalize to competitive performances.]

The physiological responses to complicated sporting activities are likely to be caused by a complicated set of physiological processes. Limiting training "theory" to one incomplete physiological model will not result in maximal fitness adaptation for a specific sport.

It is likely that training programs developed by incorporating principles from psychology, biomechanics, and physiology will stimulate the best training adaptations for a particular sport.