Challenge Decathlon - Barriers on th way to becoming the "King of Athletes"

by Günter Tidrow

AUTHOR

    Prof. Günter Tidrow is the head of the Department of Movement and Training Science at the Humboldt University in Berlin, Germany

1 - Introduction
    The topic dealt with in this article was " chosen to show the considerable barriers an athlete must overcome if he wants to fulfill the wide range of demands which are typical of the top-level decathlon. Once one is in possession of this information, it is easier to understand why there are clear limits to performance maximization in the combined events even if potential world record holders in arbitrary individual events change to the decathlon early enough.
    The statement that combined events are more than their parts is by no means new. However, it is much more difficult to identify the reasons for this imbalance. The explanation that there is a continuous accumulation of fatigue, which is unavoidable in spite of the breaks between the individual disciplines, is certainly not sufficient. However, it is true that specialists have considerably better starting conditions in each discipline of the combined events. Although it seems to be quite normal today for television companies to dictate the Olympic timetable to an increasing extent, the finals of the 100 m or 110 m hurdles, for example, have not yet been scheduled at eight o'clock in the morning, which is a normal time decathletes have to cope with. In other words, even the performances in the first discipline of the decathlon cannot be directly compared with the specialists' performances, although at this stage of the competition the athletes are not fatigued at all.
    However, in the minds of the sporting public, just these sorts of comparisons, which are caused by the international presentation of the combined-event athletes as "interval" individual-discipline competitors, are considered as the seemingly objective basis for the "correct" assessment of a decathlete's current objective performance capability at one glance. The additional disadvantage that he is given only three attempts in the long jump as well as in all the throws is simply ignored.
    However, regardless of this distorted view leading to the (superficial) conclusion that the decathlon is a "catchment basin" for the less gifted one thing is correct: the specialists set the standards by which each combined-event athlete must be assessed as to the extent to which he has approached the ideal of perfection across the spectrum of events. However, this statement only applies if the transformation of the individual results into points, which is necessary for determining a winner precisely and objectively, and thus the scoring systems, reflects this reference basis (Ulbrich 1950; Tidow 1983b). Otherwise it could be no longer guaranteed that the best all-round athlete is the winner rather than merely the athlete whose individual performance capability best matches the characteristics of the scoring system. This is exactly the case with the current scoring tables of the IAAF, which were introduced in 1985 (Tidow 1989d). Beyond a certain point, the scoring system favours throwing and jumping performances and discriminates against sprinting performances of the same international standard. This situation undoubtedly has a bearing on talent selection and combined-events training and is demonstrated by a comparison of the development of the decathletes' relative performance ability in the individual decathlon disciplines.
    It is a general fact that the superiority of the specialists varies considerably from discipline to discipline. For decades, as far as velocity is concerned, decathletes have come closest to the specialist level in the long jump and in the (hurdles) sprint (93%), while in the throws and in the 1500m decathletes are farthest away from the specialists (ca. 75%) (Tidow 1981c; Tidow 1989d). In Figure 1 the gaps between the ten decathletes with the highest scores and the ten best specialists in each event are presented in the form of velocity percentage values (mean velocity in the runs, take-off velocities in the jumps and release velocities in the throws). The comparison between 1980 and 1996 shows a far-reaching parallelism of the decline in the relative level of performance attained: The difference has become smaller in the throws, whereas it has become clearly bigger in the high jump as well as in the 1500m race.

    The reduction of the performance gaps in the throws, including the shot put, might be caused by two primary factors: on the one hand stricter doping controls have reduced the average performance ability of the top throwers since the beginning of the nineties, on the other hand the above-mentioned influence of the scoring tables adopted in 1985 becomes noticeable. According to this system, throwing performances are scored progressively from a certain level of performance onwards. Correspondingly, at least some of the decathletes of the new generation with the best scores show certain strengths here while hardly anyone shows striking weaknesses. The price of this is a reduced performance ability of the best decathletes in the 1500m and in the high jump, as compared with 1980, while there has been an increase in the performance level of the specialists. Consequently the developmental dynamics of the individual and combined-events athletes is characterised by a convergence in the throws and, in contrast to this, a divergence in the high jump and the 1500m.
    When interpreting the performance gaps it must be taken into account that the arithmetic mean values are representative only for specialists competing in events with a very great performance density. In contrast to this, decathletes show a rather wide variation, so that in individual cases there are considerably greater or smaller distances to the specialist level (see vertical beams in the white columns of the decathletes in relation to the velocity ranges of the specialists on top of this). This implies that it is obviously possible to be successful in the decathlon with a quite different performance background. The resulting performance structure is the product of possibly scoring-orientated training and individual talent. This can be characterised by strengths, as for example in the sprinting, jumping or throwing disciplines, or it can be balanced (Joch 1969, 1973, 1975; Tidow 1981a, 1983a, 1988).

2 - Prospects of success in athletics
    When one analyses the world ranking lists as well as the results in the World Championships and Olympic Games, it becomes obvious that there are only few athletes who are successful at the highest level in more than one speed-strength event. Even where rare examples can be found they are virtually all restricted to the following combinations of two disciplines: 100m and long jump or shot put and discus throw. It is extremely rare to find athletes competing internationally in three disciplines at the same stage in their career.
The obvious conclusion is that specialists predominate, and there are no traces of true 'all-round athletes'. Thus, when looked at in more detail, athletics is a "collective sport" for a great number of individual competitors who, from an interdisciplinary point of view, have nothing more in common than the intention to surpass each other and themselves. Of course this also applies to combined-event athletes. However, they are the only athletes who take up the challenge of competing across the whole range of athletics disciplines unlike, for example, long jumpers, shot putters or middle distance runners and are therefore the only true track and field athletes.
    It seems to be remarkable that even with combined-event athletes very few discipline combinations exhibit a significant internal relationship: correlation-statistical analyses (Bäumler/Rieder 1972; linden 1977; Kunz 1980; Joch 1981) unanimously show that these disciplines are identical with those where as mentioned above few specialists are placed in the world ranking lists (in decathletes there is additionally only the 'plausible' connection between the 100 and 400m, which is no attractive double start combination for specialists). This means that, as far as performance is concerned, the majority of the combined-event disciplines are independent from one another, as it were, even with those athletes who pursue the ideal of universality.
    The question as to the causes of this necessity to specialize in one event in order to achieve top-level performances in athletics has as yet hardly been dealt with. However, giving an answer to this question seems to be the key for understanding why it is right to regard the "voluntary" grappling with ten disciplines as a permanent challenge.
    This question can be approached by trying first of all to trace the determinants of success in the individual athletics disciplines. Everybody knows that without talent nothing is achieved! As far as content is concerned, this concept can be filled with four 'dimensions', the two pairs of which are connected at least to some extent (see Figure 2). Only the first pair is clearly visible and can be identified by the expert almost at first glance. The second pair of determinants, which most definitely decide performance in the end, remains in the dark to a great extent.

    One speaks of a 'natural movement talent' when a young individual is either able to realise important elements of a target technique right away or when he or she needs only a small amount of instruction in order to be able to execute complex motor skills correctly. According to the current state of knowledge, such gifts are mainly based on the movement experiences an athlete has gained from early childhood by being offered a great variety of movement opportunities (Joch 1974; Tidow 1988).
    When, in addition to this, the talented individual exhibits a great propelling capacity or flexibility which matches the mechanical or energetic requirements of the respective discipline, two of the four talent factors are fulfilled. Performance advantages are almost an automatic consequence of this.
    To what extent a talented individual becomes a top-level athlete is almost exclusively dependent on untapped adaptation reserves in combination with a high load tolerance. When both prerequisites for development are fulfilled, that coach will be successful who links up with a permanently highly motivated athlete with the greatest adaptation reserves (and in whose coaching he makes only few mistakes).
    The reason why this process is always exciting is that as yet there is no measuring instrument available which enables a reliable estimation of the potential for development lying dormant in an athlete. The amount of this potential is revealed only after years of training if at all. This is the problem with all talent promotion programmes. (Contrary to this, success in the decathlon is neither dependent on extremely great adaptation reserves nor on their complete exploitation. Although this generally increases the chances of decathletes to be successful, the probability that an individual athlete is an "all-round competitor" with developmental possibilities in a variety of disciplines decreases in proportion with the required level of performance.)

3 - Specialization effects
    It takes between five and ten years to attain world-class level in a certain discipline. Even if it seems far fetched to multiply this number of years by the number of the technical disciplines in order to determine the period of time which is necessary to produce a top-level decathlete" this is correct at least to the extent that the special talent can develop without being influenced by disturbing variables. In contrast to this, combined-event athletes, who must permanently deal with a lot of disciplines, are almost systematically hindered from specialising universally, so to speak. Quite bluntly, there is no possibility of a cumulative specialization for a decathlete even if his physical, motor and techno-motor preparation is distributed over many years in one discipline after the other. This is mainly caused by the fact that the motor system must bring the respective discipline-specific impulse patterns in line with the current driving conditions. It is very probable that the resulting refinement cannot be exchanged or called up at will at a certain point in time but can only be changed over a certain period of time in favour of one specific discipline at the expense of another discipline. How important an undisturbed time of development in one discipline is for an optimal exploitation of talent can be shown with different phenomena, which can be tracked down in specialists.

3.1 - Co-ordination: "Movement centering"
When, in the world-best specialists, the ranges of time measured in those disciplines of the decathlon which are limited by speed-strength are analysed, it becomes obvious that in the respective core phases of force transmission to the body or to the implement not more than 100msec are available (see Figure 3). In all eight disciplines the goal is an absolute maximization of velocity. To this end the motor system uses ballistic movements (Tidow 1982). Such actions, which are the fastest that a human being is capable of, take place in a pre-programmed way. When they have been activated, it is not possible to correct them during the execution. This applies even if the athlete - in spite of the extremely short duration and complexity of the movement - should have been able to discover such a deviation in a split-second because of his sharpened movement awareness. Consequently, if there is a programme error, an attempt at deleting this error can only take place after the result. How fast (or slowly) a necessary change of the programme can be translated into practice is primarily dependent on the degree of automation. Experience teaches that the older and more firmly established the respective impulse pattern is, the more resistant it is to correction.

    With the movement tasks included in the sprinting, jumping and throwing disciplines only achievable by using the gross motor system, the goal to reach maximum velocities leads, firstly, to an optimal intermuscular co-ordination of the partial impulses in relation to time and, secondly, to a maxi- mum intramuscular time related activation of the terminal accelerators.
    The main reason why this is only possible in an individual in a specific discipline instead of in all disciplines is that the movement tasks differ from one another. In the sprint, for example, the athlete has the task to integrate the swinging elements into the push-off, to ensure force transmission through the stabilisation of the trunk and to create the best working conditions for the respective agonists and optimally long micro-regeneration phases for the respective antagonists through the maximally fast alternation of tension and relaxation. Just as with the jumps and throws, this takes place under enormous time pressure because, in the respective core phases, the athlete's body (or the implement) is already in (very fast) movement caused by pre-acceleration.
    A consequence of this is that in the sprinting, jumping and throwing disciplines there are no stationary strength efforts, as for ex- ample in the tennis serve. Neither can track and field athletes make use of a second chance, comparable to the second serve available to tennis players, because of the requirement of maximization. A reduction in velocity by 10 to 15%, which is typical of the second serve in tennis, would lead to more than poor results in the throws - with a loss of distance of about 4m (in the shot put) or up to 20m (in the javelin throw)! In other words: In the speed-strength disciplines of athletics the securing of an attempt through a decrease in intensity, which is inconspicuous and rather normal in non-cgs sports, would lead to differences which would neutralize the performance advantage of the best specialists in the world over the decathletes with the best scores (see Figure 1: the difference of 15% in the release velocity of the javelin corresponds with a difference in distance of 24m - i.e. the difference between 89 and 65m).
    In trying to find a balance of the career of a world-class thrower or jumper, all the technically relevant kinetors (= movement creators) need to be taken to an increasingly higher level of performance through above- threshold strength training loads being repeated periodically until the adaptation re- serves are more or less exploited. By executing the target technique repetitively many thousands of times, the kinetors are matched with and adjusted to one another to transform acquired strength into movement speed maxima. This "centring of movement", which sometimes takes more than ten years requires a neuronal programme predominance, which includes the muscle spindles and is often associated with a restriction in the scope of the muscular action. Such effects of specialization become apparent if one persuades world-class athletes to start (again) in disciplines which they were good at from a technomotor point of view when they were young. In most of these athletes there is then a considerable gap between the extreme muscular potential and the (modest) result achieved on this basis.

3.2 - Strength and flexibility: Angle specificity
    When one analyses the working angles which are existent in the core phases of each combined-event discipline (e.g. in the knee joint of the take-off leg, the elbow joint of the throwing arm or as related to the trunk torque), there are rarely congruities. Added to this is the fact that the working conditions especially as far as dynamics is concerned are not identical. Therefore, an interdisciplinary synopsis of the statically represented front support and rear support phases in the sprint and jumps as well as of the release positions can confirm this finding only indirectly (see Figures 4, 5, 6). In comparing, for example, the run-up velocities in the long and high jump, which differ by up to 4m/sec, it is quite obvious that the long jump take-off leg is loaded "in a different way" than in the high jump, regardless of the bracing angle.

    Taking into account a certain movement affinity between the shot put and the discus throw (Kunz 1984), these differences can be interpreted to the extent that, for the creation of an optimal acceleration impulse, at least three requirements must be fulfilled from a discipline-specific point of view:

    ● First of all, the muscle fibre lengths of the motor units must guarantee the highest mechanical efficiency through an optimal amount of overlapping of the actin and myosin filaments.

    ● Secondly, a correctly timed maximum activation of the driving muscles.

    ● Thirdly, a corresponding optimally timed deactivation of the antagonists.
 

    Apart from these demands made on the target muscles (and their respective antagonists), corresponding demands apply to the postural muscles, too. Experiments show that the degree of neuronal activation (of a flexor or extensor) co-varies with the angular position of the joint and moves towards a maximum within a certain small angular lone. Should the situation occur that, during muscle contractions for a period of several weeks, a different angular position is isometrically pre-determined, the maximum activation which can be quantified using EMG analysis moves in the direction of the training position (Thepaut-Mathieu et al. 1988). At the same time there is a change of that angular position of the joint, where the maximum angular momentum is produced. It must be assumed as a hypothesis that these results are based on two adaptive mechanisms: in terms of the neuronal system, every contraction command not only includes excitatory but also inhibitory impulses. Against this background, the angular specificity is based on the fact that during the activation of the respective flexors/extensors in everyday (habitual) angular positions of the joint, a large amount of the neural drive reaches the motor end-plates without inhibition. However, in rather unfamiliar angular positions (which are normally not used to create maximum forces) there is a stronger inhibition. The adaptive reserve in the area of muscle mechanics consists of the adjustment of the fibre length and thus the optimal degree of overlapping in such a way that the greatest angular momentum or the greatest active tension is reached in a position which is normally characterised by the highest strength demands (Herring et al. 1984).
    It has already been mentioned that these strength demands resemble each other only to some extent if at all. Correspondingly, in terms of time, it is not possible for a driving mechanism to exist which is equally optimal or which can provide an identical maximum neural activation for all disciplines. From a neuromuscular point of view, the term 'special strength', which is often used in athletics, can be attributed to the adaptation mechanisms mentioned here.

3.3 - laterality: Hypertrophy, hyperplasia, contractility
    Lateral preferences imply that in the motor context all human beings are specialised by nature, so to speak. The lifelong preference for one extremity e.g. the right arm or the left leg as well as a predilection for a certain direction when turning around or rotating about one's longitudinal axis, which gets steadily firmer from childhood onwards, eventually leads to a more or less marked muscular asymmetry, which can even be osseous in competitive athletes.
    It has, for example, been demonstrated by autopsies that the muscles of the right lower arm in right-handers exhibit a fibre transformation: According to Fugl-Meyer et al. (1982) there are significantly more slow twitch fibres in the dominant arm implying a higher fatigue resistance. Probably induced by the abutment function of the contralateral left leg, certain muscle groups of the lower left leg show a greater population of fibres in right-handers indicating hyperplasia (Sjostrom et al. 1991). Applying planimetric magnetic resonance imaging of the trunk muscles of 122 trainees (average age: 18 years). we ourselves could demonstrate that the left side of the body of the right-handers (n=112) showed a significantly greater cross-sectional area (Tidow et al. 1997). This finding seems even more remarkable because there were no competitive athletes among the people examined. In individual cases the difference was as much as 14%. When one considers that carrying loads with the preferred hand means a stress on the arm muscles of the same side and a simultaneous activation of the contra-lateral trunk muscles for the stabilisation of one's balance, these functional asymmetries become plausible.
    The results of the measurements of leg lengths in Scandinavian track and field athletes of various disciplines 63 jumpers and 86 runners are more surprising (ef. Friberg/Kvist 1988). According to these measurements, 69% of all long and high jumpers had a take-off leg which was 0.5 - 2.5cm longer than the other leg. In contrast to this, in sprinters the leg length difference was much less pronounced if existent at all (which was the case in 19%). While the mechanical advantage of a longer take-off leg is obvious, it is more problematic to relate cause and effect to one another as far as time is concerned. The question is whether the higher stress which had been placed on the take-off leg over a period of many years had eventually induced an osseous adaptation as is typical of top-level tennis players as far as their playing arm is concerned or whether intuitively the respectively longer leg had been chosen as the take-off leg.
    Furthermore, it is remarkable that when testing muscular contractility by means of electrostimulation it could be verified that, for example, hurdlers as well as high jumpers and pole vaulters exhibit a higher muscle contractility in their swing leg than in their take-off leg (cf. Absaljamow et al. 1976). Here the authors assume that the decrease in contractility was caused by the higher mechanical load. In animal experiments Caiozzo et al. (1992) used above-threshold strength training of one leg to induce an analogous, highly significant left transformation in the fibre spectrum of the fast running muscles, which occurred only in the target leg.

3.4 - Sense of balance: Habituation
    Body posture, orientation in space and direction stability are controlled by the vestibular system. Feelings of dizziness occurring directly after rotations indicate that this organ is very sensitive to higher accelerations and affects the support-motor system with decreasing intensity (Bartmus 1987; Neumann 1991). Although correct body posture, orientation within the space of the throwing circle, and stability of direction as related to the throwing sector are elementary requirements for a technically acceptable discus throw, the 11/2 turns preparing for the release do not cause feelings of dizziness in anybody.
    This is probably the reason why for a long time both coaches and athletes have underestimated the significance of a sense of balance which is immune against rotations. To what extent this statement is justified in individual cases can be clarified quickly by using a simple test. The athlete touches a men's shot lying on the ground with the tips of the hand of his swinging arm and, while maintaining this contact, he runs around the shot as fast as he can ten times to the left (right-handers) or to the right (left-handers). Right after this, he is told to walk a distance of 10m along a line. If he succeeds in this, an untrained sense of balance can be ruled out as the cause of demonstrated, hard to correct technical deficits in the discus throw. However, studies which we have conducted with a great number of young decathletes show that none of them was able to fulfill the actual test task walking along the line even to some extent. They would have fallen to the ground in a completely uncontrollable manner if they had not been caught by companions who had been positioned precisely for this purpose. Unlike the decathletes, the specialists were not only able to walk along the line but they could even run along it and afterwards they asked what the problem was ...
    In special terminology this phenomenon of an indifference towards rotary accelerations is called habituation. In common with other adaptive phenomena however, this habituation, too, is not stable and permanently effective but reversible. Once the athlete lays off executing the rotary movement for a few weeks, his sensitivity will increase again, which means that the rotation will lead to an impaired equilibrium.
    Local conditions during the preparatory period hinder most decathletes from throwing the discus with a full turn, so almost no stress is placed on their vestibular system as far as rotations about the longitudinal axis are concerned for a period of up to six months. Correspondingly, each year the same insecurities in the throwing circle are preprogrammed. In addition to this, an athlete training by throwing implements in series for example five consecutive throws will bring about a serial, unconscious increase in the load placed on the vestibular system because by each consecutive trial a new stimulus is set within the abating phase. The same is the case when during the preparation for competition (in the decathlon) a maximum number of warm-up attempts is executed one after the other as fast as possible.
    Against this background, the increasing frequency of movement faults and the simultaneously decreasing possibility of correction in the same discus technique training session can be explained. By now the remedy is known to everybody: Rotations about the longitudinal axis with and without implements which closely resemble the throwing technique and which are optimally executed along the lines on the track are a part of the standard warm-up repertoire of decathletes all through the year. This way it is possible to avoid rotation-induced irritations of one's equilibrium. Consequently, at least as far as this aspect is concerned, the specialists can
no longer claim to be at a notable advantage.
 

3.5 - Speed and endurance: energy supply
    Steve Ovett, the former world record holder over one mile, is reported to have said that he tried to annoy his team mate Daley Thompson, who was at that time world record holder in the decathlon, by remarking that the decathlon consisted of nine Mickey Mouse disciplines and one genuine competition - namely the l,500m race. The fact that middle distance athletes in particular refuse to pledge their allegiance to the "kings of athletes" is not without good reason. The gap in performance between themselves and the decathletes is by far the greatest of all the disciplines (see Figure 1).
    One reason for this is the energy supply which predominates in the individual competitions of the decathlon because that in it- self highlights the special role played by the 1500m event. Primarily anaerobic mechanisms are activated in nine disciplines; alactacid mechanisms in the throws and jumps while in the 100m and 110m hurdles sprint, and especially in the 400m event, alactacid plus lactacid mechanisms are involved. In contrast, world-class performances in the 1,500m are inconceivable without a highly developed aerobic capacity (see Figure 7).

    From this point of view, the decathlon consists of 9 anaerobic speed-strength disciplines and a primarily aerobic endurance contest.
    The chances of success are distributed correspondingly: athletes who by nature are supplied with a majority of type lib fibres in their arms and legs have the best prerequisites from the point of view of muscle mechanics to achieve brilliant performances in the throwing and jumping disciplines. However, because the three sprint disciplines re- quire energy supply for about 22 (100m), 25 (110m hurdles) and 100 muscle contractions (400m) per leg these demands in training and competition make corresponding adaptations at least in the running muscles absolutely necessary.
    With decathletes this leads to a reduction of the original explosiveness of their legs. This is particularly true in relation to the specialists in the throws and to some extent even in relation to the specialists in the jumps.
    As far as the 1,500m race is concerned, there is some evidence that the aerobic capacity of the type II fibres too can be considerably increased through correspond i ng amounts of training. However, this always has negative effects on their contractility (Hather et al. 1991; Tidow 1994e). The securing of the energy supply is the highest priority of the biological system, and as a result, the muscle cells of the faster type (i.e. llb and lla fibres) are - in proportion to the training volumes - transformed in the direction of a higher resistance to fatigue and are correspondingly equipped with more mitochondria, aerobic enzymes and develop a higher capillary density. This enables them to be used for longer periods of time and, in the context of an "intramuscular rotation mechanism", they can contribute to the micro-regeneration of the motor units even during the (running) exercise. This is only possible through a reduction in the performance capacity of the sarcoplasmatic reticulum and the cross section of the fibres. However, the main effect is a considerable decrease in the concentration of ATPase. This enzyme is necessary for the splitting of ATP. The more ATPase is available, the more cross-bridge cycles can be realised per unit of time. This in turn means that the ATPase concentration in a muscle fibre limits its contractility (Larsson/Moss 1993).
    Middle distance specific training loads, which result in an increase of the aerobic capacity, lead to a decrease in the jumping and throwing performance, possibly even in the 100m performance, although the 1,500m performance will improve considerably. To avoid any misunderstanding, nothing is wrong with the use of extensive cross-country runs for the development of an aerobic base as well as for regeneration during the preparation period. On the contrary, every decathlete should be able to move his own body weight for at least 45 minutes at a rather moderate speed as compared with a specialist (Kudu 1971; Sadurski/Mankiewicz 1975; Kudu 1976; Seropjogin 1980). This is particularly important because the recovery between the disciplines and between the competition days takes place exclusively aerobically.
    When the running performances of specialists over the 1500m distance are compared with those of decathletes, the systems of energy provision which are available to these groups differ considerably. The maximal oxygen uptake (V02max) of decathletes is about 55 ml O2 x kg^-1 on average (Scheele 1972; Parnat et al. 1973; Berg et al. 1983; Tidow et al. 1983), whereas the V02max of specialists is actually more than 40% higher. Therefore the decathletes, who have powerful leg muscles, are forced to use anaerobic-lactacid mechanisms earlier and to a greater extent than the middle-distance runners. The result is an acidosis which begins early on and increases steadily during the course of the race because of the lack of possibility for compensation (this is particularly because the trunk and arm muscles of the top-level decathletes consist of predominantly type II fibres).
    The lactate values, which in spite of considerably worse running times are significantly higher than those measured in specialists, are proof of the anaerobic share in energy provision which in relation to the slow running times is over-proportionally high. After a 4:20 min run, a decathlete showed a post-exercise lactate value of more than 25 mmol/I (Tidow et al. 1983). On the other hand, the maximum lactate values of many decathletes after the 1,500m and 400m race do not differ much from one another. When there is an additionally low oxygen partial pressure caused by exposure to altitude as during the Olympic Games in Mexico City the performance difference between the decathletes and specialists becomes even greater (Tidow 1991d).In the heptathlon the 800m race does not tax the athletes to a comparable degree (although their personal feeling is certainly quite different] because the anaerobic share in energy provision is at least half of the energy needed. Therefore specialization in the 800m does not depend so much on a high aerobic capacity as a corresponding specialization in the 1500m. This is possibly the explanation for the greater ability of heptathletes to compete with specialists and the smaller relative differences in performance.

3.6 - Movement control: visual information processing
    The long jump is characterised by the fact that, regardless of the take-off point, the result is always recorded from the front edge of the take-off board, i.e. the take-off line. Therefore the run-up in the long jump is not a mere approach but includes the movement task to h it a certain spot precisely. It is a well-known fact that the precise placement of the take-off foot onto the board is sometimes even difficult for specialists. As placement errors occur under steady or even calm wind conditions, too, and because some athletes have more run up problems than other athletes, the following causality may be assumed: if the run-up consists of 20 strides, the acceleration towards the board is provided for by 20 push-off impulses. When one compares different attempts, these impulses are very similar although there is a great probability that they are rarely identical. The result of this is a variability in the run-up pattern. However, if the athlete does not make any gross corrections, i.e. if he does not chop or lengthen his strides, this variability is hardly noticed. Moreover, this is even more the case when the board is reached during every attempt. The precisely measured run-up which the athlete utilises on the day of competition is based on a mean value which has been established days (or even weeks) before by way of trial and error.
    When the athlete's shape is different on the day of competition, there are bound to be difficulties in adaptation. The 'external' adaptation takes place by moving the checkmark backward or forward. The 'internal' adaptations, on the other hand, take place almost unnoticed in the form of stride variations. Those athletes who are able to visually perceive their relative position in relation to the board can make adaptations by varying the impulses, particularly in the middle section of the run-up. On the other hand, those athletes showing deficiencies in the visual-dynamic area will have difficulties which will be all the greater the more the daily rhythm and form of the athlete deviates from the shape he was in on the day when he established the length of his run-up.
    The art of the jumper therefore consists of the ability to make fine corrections in stride lengths during the run-up on the basis of visual information in such a way that the following direct take-off preparation can then take place in an undisturbed way according to a fixed pattern. This strategy does not always work completely without error, a fact that becomes especially obvious when the athlete enters the competition in his best shape. Particularly those jumps where the athlete oversteps the board only by a narrow margin are more than once over-proportionally long. This may additionally be caused by the fact that a somewhat sharper bracing angle was intuitively chosen to correspond with the higher run-up velocity. With the horizontal distance of the head/eyes in relation to the scratch line remaining identical, this causes the front of the take-off foot to be a little further forward which leads to a fouled attempt.
    There are at least three other decathlon disciplines in which, similar to the long jump, the resulting performance depends on the athlete's ability to process visual information during locomotion as precisely as possible and to utilise this information immediately in a dynamic way. However, in these disciplines the demands are even higher because a certain spot which is not marked and therefore cannot be seen must nevertheless be hit as exactly as possible. This is the case in the sprint hurdles, the pole vault and in the high jump, too. Here the athlete is required to hit the optimal point of take-off in front of the obstacles or the take-off point, matching the grip height or the height of the bar.
    How difficult this can be even for hurdle specialists is highlighted by getting them to wear special glasses which prevent them from seeing the hurdles. Not one of the specialists was even able to clear the first hurdle without difficulty and most of them were only able to clear the second hurdle by using a safety jump (Schnell 1996). This finding is particularly remarkable because in this experiment the run-up distance to the first hurdle and the distances between the hurdles were standard. This means that the conditions did not differ from the conditions the athletes were accustomed to and under which they had developed and reproduced their individual hurdles technique again and again in some cases for more than a decade.
    In sprint hurdles, it is also necessary to receive uninterrupted feedback about one's own relative position to the next obstacle in order to be able to adjust one's stride pattern accordingly. Unlike taking part in a sprint event in top form, where longer strides lead to a corresponding reduction of the number of strides which are necessary to reach the finish line, and also unlike the long jump (run-up) in top form, where the checkmark can be altered, the hurdles sprint is a compulsion run. Consequently, regardless of the athlete's rhythm or form on a particular day (and the wind conditions), the stride pattern must guarantee that the take off points in front of each hurdle are hit optimally. When the stride lengths 'fit', the only way out is a variation of the stride rate. In accepting this fact, even the run-up to the first hurdle requires the ability to steer oneself correspondingly on the basis of visual information (Tidow 1992, 1996b).
    In the pole vault the task consists of placing the front of the take-off foot exactly where the perpendicular dropped from the upper grip hand makes contact with the ground. This is the only way of maximising the plant angle in relation to the individually chosen grip height (Tidow 1991a). In the pole vault the visual-dynamic demands are therefore even more difficult to be fulfilled than in the long jump. After all, there is no optical target (in contrast to a long jump take-off board) and the optimal point of take-off depends on the grip height chosen. The optical point of reference for the necessary "calculations" is the pole vault box sunk into the ground as well as the landing area surrounding the box. The end of the pole must be brought into contact with the stop-board, which is 4 - 5m away from the vaulter, as exactly as possible and simultaneously with the plant of the take-off foot. In order to guarantee that this takes place smoothly the vaulter must initiate the preparation for the plant by moving the pole forward and upward in a visually controlled manner about three strides before the takeoff contact. Whether the vaulter breaks off his attempt shortly before the plant or not is consequently very much dependent on whether he subjectively perceives his own relative position including the tip of the pole, which is about 4 metres in front of him, as 'matching' the plant box or the landing area beyond the box. There are as yet no studies available which indicate how pole vaulters primarily orient themselves optically. In any case, however, the probability of error is maximally +/- 15 cm, which is very small. This means that, within this range, possibilities of compensation are available so that in spite of these deviations from the optimal point of take-off the athlete can perform a jump successfully.
    In the Fosbury flop, which has enabled all combined event athletes having only limited talent for the straddle to increase their performance considerably, the relatively slow run-up velocity (up to 7 m/sec) generally leads to much better perceptual conditions than in the other disciplines characterised by special visual-dynamic demands (long jump: up to 10.5 m/sec, hurdles sprint: up to 9 m/sec, pole vault: up to 9.6 m/sec). Actually, studies of straddle jumpers show that their run-up precision is very high with the runup velocities being almost identical. In contrast to this, even the best flop specialists demonstrate a considerable range of variation (Tidow 1990c; Killing 1995). The hint that this may be caused by the curved runup leading to greater possibilities of variation is certainly correct although it is only partly true. It is highly probable that an additional cause is the fact that with all straight runs the visual-optical frame of reference remains constant with the exception of the increasing size of the objects ca used by getting closer. To be more precise, the athlete can 'continuously' fix his look on a target object (or he is able to control the background at least peripherally) from practically the first stride onwards. In contrast, this lack of variance does not exist with curved run-ups and especially not if the take-off point is more or less in the middle between the two uprights (and not next to the upright at the side of the swinging leg).
    Specialists are confronted with these visual and motor demands every day during technical training. It is possible that the corresponding abilities are part of the basic discipline-specific prerequisites which talented young athletes must fulfill. In any case, however, combined-event athletes can acquire the necessary competence if their training is oriented accordingly e.g. after each long jump attempt the athlete indicates his perceived position in relation to the scratch line whereupon he is immediately shown his real take-off point. Perhaps it is then even an advantage to be forced to solve different visual-dynamic locomotor tasks in order to optimise the quality of processing visual information and their immediate translation into movements (Oberbeck 1980).

3.7 - Synopsis: Maximization of performance through the development of sub-systems

    In trying to draw a conclusion from the findings presented, there is a high probability that the concentrated dealing with one and the same movement task over many years with the pressure for absolute performance maximization finally leads to a reorganisation of the active and passive movement apparatus, to an optimization of the respective neural impulse pattern and to an accordingly adapted energy supply. In other words: specialization means the development of discipline-specific sub-systems (see Figure 8).

    It has been shown that a specialist is particularly successful if he is equipped by nature with the modules necessary for developing the driving mechanisms which are optimal for his discipline from the point of view of muscle mechanics, energy supply and co-ordination. In the case of mechanisms developed to perfection in the course of a preparation process taking many years, it is not possible to be similarly successful in other disciplines (if this is still the case, one has either chosen the wrong discipline or trained wrongly ...).   For this a different sub-system would be needed. This statement particularly applies to disciplines with an acyclic finish, i.e., the jumps and throws.
    In the running events there are naturally smooth transitions, especially in the case of longer distances. However, the discussion about the fastest man in the world which took place in 1997, shows that even the 100m and 200m distances are rarely dominated by one and the same sprinter. For Donovan Bailey the 200m event was a bit too long because of the developed nature of his training state and energy supplies, whereas for the quarter-miler Michael Johnson the 100m event was somewhat short because of his slightly lower maximal acceleration capacity.

FROM IAAF/NSA 2 - 00