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ENGLISH (I). About K'TEST-TOTAL ( soccer field laboratory in). Principles. Physiological arguments.


                                                                                                                                                             by Ionel Colonel

                                                                               " How far can we push the limits of the lab tests and

                                                  how much constraint do they bring on the football field?”

    K’TEST-TOTAL (Field lab). Scientific and methodological background.

      The determination of the maximum amount of O2 that the body consumes during effort is considered to be the leader of the methods that measure the capacity of effort. Its data fidelity and objectivity and its echo in physiology are undeniable. Taking into account the fact that this method is widely used all over the world, the data that it supplies have become an important reference mark in training players of many teams. Their training results are compared with its value scales, which enables stating the physical potential of the players with regard to both their training and their physical abilities in playing the game. Together with monitoring the cardiac activity and measuring the level of lactic acid in the blood, during and after effort (and other biochemical tests), the determination of the maximum amount of O2 that the body consumes during effort (VO2 max.) gives an ample physiological profile of a player. Of course, under some reservations that are to be discussed further on.

       Related to this method, the countless number of lab and field tests that have been developed so far pretend to provide 92 or even 97% compatibility with the results given by the average VO2 max. test. This has happened because the VO2 max. measuring devices are quite expensive.

      In order to make our introduction complete, it is essential to mention that VO2 max. must be measured only during the increase in intensity of straight running.

      Paradoxically, a short account of the results obtained by monitoring systems of parties such as Amisco, ProZone, Digital Soccer, SICS, Human Performance Lab, MAPEI Sport etc. entails such data that any scientific research management regarding the present day methodology of measuring the capacity of effort would find surprising. The data conglomerate is puzzling by:

- the small share given to straight running (compared with the test intensity);

- its biometrical character, totally different from straight running, where the largest amount of energy is consumed while doing mechanical work;

- the huge difference between the (minor) neuro-muscular consumption needed in straight running and the one needed in the other motive power structures involved in football.

      We will give below an account of the motive activities of a player during an approximately 90-minute game.

       Due to the players different field position, we must accept (we think you do too) two limits, the upper/superior limit and the lower/inferior limit.

1. 15-30 duels for the ball, on the ground or in the air, preceded and followed by several motive moves of various intensities;

2. a considerable number of running starts (of various intensities) and running a certain distance (40-55 at a speed of 15-21 km/h, 13-25 at a speed of 21-24 km/h, 15-20 at a speed of 21-24 km/h.);

3. fast decelerations from a high speed, and followed by several motive moves of various intensities, 5-20;

4. other decelerations, of lower intensity, 5-20;

5. 30-73 passes, done from various body postures, preceded and followed by several motive moves of various intensities;

6. 15-40 changes of direction, at an angle of more than 90º, at different running speeds;

7. hand to hand fight with other players in order to get the first position/to catch the ball, while playing or before carrying out still phases (10-50);

8. alternating various types of running: forwards, backwards, sideways, to feel the pulse of the game etc. (15-30);

9. others, such as: shifting the player’s centroid outside his projection area, due to intended but rapidly failed participation to a certain playing phase; countless motive moves needed when controlling and leading the ball; tense moments before carrying out still phases (corners, free kicks), when the players move a lot before sprinting to catch the ball, fight the opponent or cover a player.

   *** We have confined ourselves to mention them as terms, without pointing out their morpho-physiological background elements such as: the amplitude of Motor Unit recruiting, intra- and inter-muscular coordination, work speed while alternating agonistic-antagonistic muscle contractions, neuro-muscular activity, peaks of eccentric and concentric contractions, amplitude of lever work etc. It is true that all these aspects can also be found in the case of cyclic / straight running, but a question is raised here: what are the reference points for intensity and amplitude in these two cases?

     Metaphorically speaking, we can say that the specialized monitoring systems mentioned above highlight an ample picture, whose paint abounds in a huge number of gestures and moves of a great motive diversity and complexity, where there is a part concerning linearity-monotony (only as a pale background), but in an amount which is too small compared to its importance. It is not justified.

      We wonder how we can quantify and classify the above-mentioned motive and physiological aspects, as a whole, so as:

- there should be a direct relation between the test result and the parameters of playing;

   the test result should clearly point out the levels at which each motive feature, especially in its complex or associated form (e.g. instead of talking of ‘straight running speed’ we should use the term ‘acceleration-deceleration speed followed by something else’ such as ‘a change of direction’ or a jump’) momentarily adapts to its specific effort;

- the correlations between the partial results should clearly point out possible training deficiencies on physiological targets;

- the picture of the player’s individual features, seen as a whole, should highlight the possible limitations, where the progress rate would be too small comparing it to the work to be done;

- last but not least, it should provide compatibility to similar data, within the boundaries of an integrated national or even international system, on the grounds that the morpho-physiological parameters are universally valid.

     Principles. Physiological arguments.

     In addition to the necessary correlation between the quality of complex/specific field determination and the accuracy of the lab tests, K’TEST TOTAL is a great step forward in the attempt of designing an instrument that specialists could use to get the most articulate data about the players.

     Perhaps more important than these features is the fact that the specialists need to have a conglomerate of data supplied by a single test which has to be able to point out more than a simple momentary, adaptative state or a single effort element.

      Presently, in the football world, several aspects are tested: the capacity of effort (VO2 max.), speed, aerobic resistance, explosive force, sprint force (with determination of lactic acid level in the blood) etc. Everything is done according to some reference points, training sessions/stages, adjustment training stages designed for specific periods of time, specific methods. It is a whole system that is tightly related to the competitional calendar. A database is thus created, which can be used to give the ‘able to play’ verdict with regard to the player’s capacity of effort.

      There are many times when the player does not feel the acme of accumulations. From this point of view, the player’s feed-back does not assure the state anticipated by the doctor/trainer. Of course, there are many possible explanations for this situation according to present methodology but, taking into account the way it is orientated, it only touches the topic partially and superficially. That is why we suggest a new concept, namely the adjustment to the maximum fitness condition, which is to be discussed further on.

       Relative to this concept, K’TEST TOTAL criteria have been modified in the course of time according to the BORG CR 10 SCALE, to the very purpose of supplying another important parameter which proves relevant for rounding off the database of top football players.

As for the physiological and metabolical targets, K’TEST TOTAL includes the following in the TRACK:

· 8-10 m. maximal sprints, which cover enough distance for the player to gather speed so as to require maximum deceleration from him;

· Changes of direction at an angle of 180º, which require deep involvement of eccentric/concentric relations – general / segmentary concentration;

· At the first hurdle, a group of maximal elements of deceleration-explosive stamina-speed-acceleration which require intense propioceptive activity on the account of exhausting of the phosphagenous reserves in the muscles involved in the effort. Carrying out the above mentioned group of elements differentiates the further players’ performances through the necessity of keeping a high rate of excitation-inhibition on the account of a previous extreme phosphagenous and neuro-muscular consumption;

· At the second hurdle, a group of elements which include unilateral deceleration (on either feet). This element requires passing from a maximal eccentric contraction to maximal concentric one in the same muscle (the quadriceps complex). It is these almost analytical performances, of great intensity, that make the difference between several players or between two different performances of the same player. It is all carried out against the background of the necessary propioceptive involvement and maximal coordination, given the accumulation of extreme metabolical exhaustion;

· The number of sprints entail considerable neuro-muscular consumption;

· The total dynamics and the diversity of the maximum intensity moves a player is capable of provide multiple opportunities of identifying deficiencies as well as of differentiating the players.

K’TEST TOTAL includes 30’’ groups of 20 m. and 50 m. sprints which must be performed at the speed required by monitorizations. The number of repetitions, the distance and the speed, the breaks between them as well as the way of accelerating and decelerating, provide the optimum correlation with a certain player’s physiological density (see the reports of the official games monitoring). Thus, the way the human body is involved in the effort (the effort parameters) is kept at a very high level (even maximal for the players who show deficiencies during effort).

→ K’TEST TOTAL (after carrying out the second track) provides multiple possibilities for data interpretation varying according to the times obtained. The exhaustion level during 7 minutes of effort influences the way players carry out the track tasks according to their own level of specific/unspecific training).

→ During K’TEST TOTAL the amount of mechanical work is almost triple compared to the specific monitoring ratio (Prozone, Amisco, etc.). We consider this ratio as the proportion between the real playing time and the amount of effort made during this interval. Example: during a 90 minutes game a player performs about 110 sprints of different intensities, which means 11 sprints in 9 minutes. The test requires 13 maximal sprints (8-20 m.), 6 sub-maximal sprints (50 m. at a speed of approx. 23 km/h) and 7 turns on the distance of 50 m. at a speed of approx. 11 km/h.

K’TEST TOTAL entails the maximum involvement of the player, but without touching those extreme points in his determination of seeing the effort through, as aerobic tests do. It is a well-known fact that players hardly accept these ones. The possibility of recording the maximum level according to the BORG CR 10 Scale in all the cases is thus eliminated. On the other hand, it often happens that a different response be recorded only within minutes in the case of aerobic tests. So, the results expressed according to the BORG CR 10 Scale show that the way the human body adjusts during training in terms of morpho-physiology is consistent with its perception and assimilation during the actual play time.

→ In addition to these, K’TEST TOTAL supplies complete data about the physiological and metabolical behaviour of the body during effort by pulse monitoring (including 5-10’ post- effort pulse monitoring) and lactic reaction (immediately after effort and afterwards).

K’TEST TOTAL can be used as a test and as a reference point, but also as a part of player’s general training. In this case, due to the mental energy and to the neuro-muscular and metabolic consumption involved, it must be used after careful planning and in the right amount. It can become an important reference point for the physiological data regarding the effort only by keeping constant conditions (training sessions, temperature, field etc.) along the whole playing season.