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.

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.

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.