Volleyball is a sport with high demands in terms of movement, ie it belongs to the group of high-intensity intermittent sports games - HIIS , which are characterized by multiple short periods of high-intensity explosive movements, separated by short rest periods, during which the athlete recovers to a greater or lesser extent. The complexity of the game is reflected in a small number of natural, opposed to a large number of performed movements, which requires greater complexity of exercise during the process of training and learning the technique .
Long term athlete development (LTAD) is considered to be a planned, structured and progressive model of directing the harmonious development of a young athlete through his sports career [2,7]. The goal is to achieve training and competitive success in a timely manner, but also to form lifelong habits of healthy physical activity . Such a structured long-term path enables talented young athletes to achieve success at the highest level.
The main aim of volleyball training is to maximize the development of all characteristics, abilities and skills with the goal of achieving elite sports results. This involves a long period of adaptation and skills consolidation. Unfortunately, very often there is a tendency to achieving these results prematurely, without taking into account the capabilities of the child's organism . A result is a number of injuries, which makes it impossible for future volleyball players to achieve their goals. Moreover, it shortens their careers and reduces their quality of life after the end of their sports career. In order to achieve the goal, it is necessary to answer the question: how do young people develop? The answer lies in the following settings, which Blanchard  presented through five basic steps for learning the elements of volleyball technique:
TELL – SHOW – TRY – OBSERVE – PRAISE AND REDIRECT!
The aim of this study was to establish what are the volleyball technical elements which the player needs to learn in a certain stage, in order to be able to move on to the next stage of learning. Also, in the modern conditions of volleyball competition, it is necessary to establish a training system, which makes volleyball academies necessary part of volleyball clubs. This is very important because such organized systems of training can give an adequate answer to the previously asked question, ie they enable the participants to go through all the necessary learning stages of the volleyball technical elements.
METHODS AND MATERIALS
The method consisted of the expert knowledge synthesis, ie the expert model application, defined from the positive practice system, based on the experience of the most successful volleyball coaches in the Republic of Serbia, Slovenia and Bosnia and Herzegovina.
BASIC CONCEPTS RELATED TO LEARNING MOTOR SKILLS IN VOLLEYBALL
General learning definitions suggest that learning is a conscious process of acquiring knowledge and skills that are most often achieved through intentional repetition . This also refers to motor learning. Most authors who have studied motor learning agree with the theory proposed in 1967 . Namely, they concluded that the motor learning process occurs in three progressive phases of learning a new skill: a) cognitive phase during which the subject develops a mental picture and a better understanding of the action needed for the executive program; b) associative phase during which the subject repeatedly performs executive program learned in the cognitive phase and; c) an autonomous phase during which the subject learns to perform the skill with little conscious effort.
Learning volleyball technique implies acquiring new skills, knowledge and characteristics, which can be decisive for successful performance. Simply put, it is the process of learning new motor movements, primarily observed through the pedagogical and psychological dimensions . The training process is characterized by a term known in physical education and sports as a "methodical procedure" or a sequence of specific, alternating actions of volleyball teachers or coaches and their students [5,9]. Within the whole series of actions between teachers (coaches) and students (players), it is also important to respect the didactic principles of systematicity and gradualness in the work itself : from known to the unknown, from easy to difficult, from simple to complex.
The learning of motor skills in volleyball begins at younger school age (between 8 and 9 years of age) and ends at 18 - 19 years of age, but the perfecting lasts almost throughout the entire volleyball career. During the learning process and working with younger athletes, it is necessary to know the manner and order of the exercise methodical procedure :
• Certain motor preparation of volleyball school players is necessary (primarily due to specificity of the volleyball sport),
• Constant explanations and new motor tasks setting, with emphasis on positive examples from practice (motivation),
• Demonstration and motor task explanation (pointing out the central details),
• Initial attempt, the beginning of exercising,
• Errors observation (occurrence of typical errors), with mandatory corrections,
• Knowledge consolidation (by repetition) and improvement of results,
• A gradual increase in movement condition complexity and,
• Summarizing the results of the training process.
STAGES OF VOLLEYBALL TECHNIQUE ADOPTION
During the "volleyball development", it is necessary to establish a system of motor (volleyball) skills learning. It is necessary to establish the dynamics of the adoption of the technical elements. The process of volleyball technique learning should be viewed as step by step. Based on the expert model application, defined through the system of positive practice based on the synthesis of most successful Serbian, Slovenian and BIH volleyball coaches experience, it can be concluded that volleyball technique learning is carried out in 5 stages:
1. Beginners – girls under 10 and boys under 11,
2. Girls under 12 and boys under 13,
3. Girls under 14 and boys under 15,
4. Girls under 16 and boys under 17,
5. Girls under 18 and boys under 19.
According to this division of the technical learning stages, it is necessary to establish which are the technical elements that the player needs to learn in a certain stage, in order to be able to move on to the next stage of learning. Hence the need to introduce the term "stage goal algorithms" in the adoption of volleyball techniques. Each stage, in accordance with certain factors, above all the learned technique, implies locomotions appropriate for that age, which on the other hand provide a positive transfer in learning more demanding technical elements .
It is necessary, prior to mentioning the stage goals in volleyball technique, to emphasize that all players do not need to be equally well adept in the manifestation of all elements. Namely, it is known that there is a specialization of playing positions in volleyball, ie each playing position implies the manifestation of several elements, necessary for the specificity of that playing position:
• setter - setting, service, block, defence and attack;
• outside hitter - service reception, attack, block, service, defence;
• middle blocker - block, service, attack, defence;
• opposite hitter - attack, block, service, defence;
• libero - service reception, defence and setting).
However, it is necessary for all players to perform certain basic elements, so that it can, later on, help in their selection and specialization. The transition from the 3rd to the 4th stage (15-16 years of age) is considered as a turning point when you need to start with a certain type of specialization in terms of playing positions. Of course, the factor of chronological and biological age should not be forgotten, because it allows some players to start later. In any case, a system must be established, which is not determined in advance, but a guideline on which path to follow in terms of acquiring volleyball skills.
The Table 1 shows 81 technical elements, which should be learned at certain stages. Each subsequent stage is conditioned by the previous one, ie when the technique is optimally adopted in one stage, the conditions are created to move on to the next stage, where the more motorically demanding technical elements are located. This approach ensures the optimally adopted technique and efficient in-game performance.
Table 1 shows 81 technical elements, which players should learn, in order to come from a beginners level to a point where the mastered technique is the basis for successful playing volleyball. It is necessary to emphasize that in the first three stages all players, without exceptions, should master the recommended technical elements, and in the 4th stage, specific training begins in terms of specialization of playing positions, where each position corresponds to requirements dictated by the game. The last stage in learning volleyball is the stage in which situational training actually begins, ie where the elements of technique are perfected through competitive exercises. In general practice, coaches tend to identify the name of a player's position with the most important technical elements for that position (setter - setting, outside hitter – attack from the side of the net, a middle blocker - blocking, libero - service reception, defence). Of course, the game also requires the performance of other elements, but these are considered crucial as they could determine the player's position.
In addition to the performance of the technical elements at a certain stage, it is necessary to include other factors that, equally, affect the athletes’ development. It is safe to say that everything that is done in the volleyball youth categories training can be summed into several words - the education of athletes. This is most efficiently organized in clubs through the so-called volleyball academies, which last 8-10 years. This period is needed for the child to reach the levels of technique, motor skills, psychological maturity and socialization, in order to be able to compete successfully.
VOLLEYBALL ACADEMIES MODEL
Volleyball academy is a specialized organizational unit for volleyball and sports training of children aged 8-9 to 18-19 (educational period of a volleyball player). Volleyball academy’s goal, through the application of specific training contents and procedures, is to contribute to the children's' maturation, proper intellectual and physical development, and thus the formation of a healthy person capable of life [10,15]. The special goal of the academy is that it contributes to the development of individual abilities of children, raising them to a higher level, in order to grow from beginners to quality volleyball players. Academies are certainly the best institutions for organized selection of children, who will train volleyball.
Volleyball academy’s tasks are :
* to use selection methods to reveal children with talent, abilities and desire for improvement in volleyball,
* to take the children through organized professional work,
* that make the academy training process optimally long,
* to contribute to the general biological development of children,
* to develop motor skills, important for volleyball,
* to make a full contribution to the development of moral and voluntary (emotional-voluntary area) traits, work on the development of psychological stability,
* to encourage children's desire to identify with athletes who possess true human values (top volleyball players),
* to provide the children with useful and healthy entertainment, as well as protection from the negative influences of the social environment.
Volleyball academy is usually organized within a volleyball club and should be conducted through five stages (degrees) (Figure 1). The volleyball academy program enables athletes to acquire the necessary knowledge in the field of volleyball (learning techniques, tactical basics, rules of the game, as well as better development of motor skills - creating a broad, stable motor base for further specialization in volleyball). Unfortunately, a large number of players do not go through all of the levels, so that through their entire playing career they have a "gap", both in technique and in the motor skills performance, character ...
Certain methods, like relay games and basic (elementary) games, should be part of every stage in volleyball academy. They would have minor modifications to make them appropriate for different age groups, as well as different goals. For younger athletes, they would sometimes be used in the main part of the training, as opposed to older stages, where they usually serve a purpose in the introductory - preparatory part of the training. Through these games, the children will get to know each other even better, because as Kajoa  says: "Tell me what you're playing, and I'll tell you who you are." Everyone reacts differently in different situations, of which there are hundreds in the game.
FIRST STAGE VOLLEYBALL ACADEMY
First stage volleyball academy athletes are girls U10 and boys U11. In general practice, physical education in these classes are taught by teachers , and rarely by physical education and sports professors or coaches. Therefore, it is necessary to entrust the selection of children for volleyball academy to a professor or coach, because he is more qualified in the field of sports. At first glance, all this seems simple, but when you take into account the age, habits and workload of children, it is clear that this part of the job is extremely difficult and responsible. The basic tasks of training in the first stage of volleyball academy are - to properly affect the physical development of children, to develop motor habits (walking, running, jumping and throwing) in different conditions, to develop motor skills in accordance with the latent motor area of children of this age. In this stage of volleyball academy, three one and a half hour long trainings a week and one competition (which does not have to be a volleyball competition) are recommended. Every activity in this period should be done through play because through it children get to know themselves and others. This is how the feeling of belonging to the collective develops. Training with the ball should not burden children with technique, but be a game, where the ball is a prop. Also, it is recommended to include competition as much as possible within the training itself (not only in volleyball but in other activities). The balls used in this stage should be lighter and larger or smaller in size (depending on the exercise). Physical preparation is focused on the development of all motor abilities. Since the period of accelerated growth and development of motor abilities of boys and girls is just beginning in this period, full attention must be given to their development. Acrobatic exercises are necessary for this period, and you should practice forward, backwards, and sideways rolls, as well as acrobatic gymnastics...
As for the coach in this stage of volleyball academy, he should be extremely qualified and should have the knowledge about technical and motor skills of this age, and especially in the psychological-pedagogical sense. The coach should be a good animator so that the children become interested in volleyball. Also, he must be an excellent demonstrator (the technique is mostly learned visually). An aggravating circumstance in this stage of volleyball academy is that there is no goal or basket, so there is no specific score in the training itself, which could have a great motivating effect on children .
SECOND STAGE VOLLEYBALL ACADEMY
U12 girls and U13 boys are included in this level of volleyball academy. In this period, the influx of new athletes is not excluded, provided that these children are suitable for this group, ie. for this stage of volleyball academy. The main task which should be fulfilled in this level of volleyball academy is a proper and harmonious physical development of the future volleyball player. To start working on training the technical elements of the volleyball game, in accordance with the child's motor abilities, as well as getting acquainted with the basic rules of the game. At this level of volleyball academy, since children have already acquired certain physical activity habits, they should practise 3 times a week for two hours, plus one game (within a group or with another academy). Unlike the previous level, where the imperative was on the general development and training habits, in this level the specific training begins, ie training of volleyball technical elements (elements of technique with and without the ball - described in the chapter "Algorithms of volleyball technique adoption stages”).
One must strive for the children to perform the technical elements correctly and precisely when adopting a technique. It is best to adopt the technique through games because games are closest to children of that age and through it, the technique is adopted the fastest. This is very important because exercise will become more interesting and diverse. It is important to emphasize that the children start playing across the net as soon as possible, even if they only use the overhead pass technique. The training should follow to the basic didactic principles of the methodology of learning new technical elements: from easier to harder, from simpler to more complex, from known to unknown... The child in this period should never follow strict movement patterns of training and exercise, but express more creativity and freedom with the ball. Physical preparation is focused on the development of overall motor abilities with special emphasis on movement coordination, but also on movement speed (speed of locomotion and starting speed). As for acrobatics, it still represents a certain base, and the training plan and program should include all the elements contained in the physical education classes for this age. An extremely important factor in this training stage, is the demonstration, ie the correct demonstration of the technique that children should adopt in this stage of volleyball academy.
THIRD STAGE VOLLEYBALL ACADEMY
This age implies a competitive team, which participates in various leagues (city, region, province and state). The third stage of the volleyball academy includes girls U14 and boys U15. Even in this stage of the academy, the influx of children is not excluded, but this time talented children, who are ahead of their generation in terms of motor abilities and longitudinal dimensionality. The tasks of training in this period are - further proper and harmonious physical development, improvement of adopted technical elements and continued adoption of new elements, theoretical work with children (tactics and tactical variants, game systems, team composition and rules of the game, which should be known at this stage in order to play matches). Since this is a competing group, it is recommended to train 4 times a week for two hours, plus once a week matches either within the group or as a part of the championship. In this period children are trained with competitive technique, ie the use of the technique in competitive conditions, game conditions (the exact choice of techniques for this age is given in the chapter: "Algorithms of volleyball technique adoption stages”). A combined method is used in training and development, ie situational method. It is believed that this method will give much better results for a simple reason because children learn the applied technique, ie the technique that they will manifest in the game. One of the golden rules of training is: "Train what you will manifest in the game" . Their efficiency in manifesting the technique will be higher compared to those who learn the technique sequentially.
Physical preparation is still focused on the development of total overall motor abilities, with special attention to the development of speed and explosiveness, coordination, as well as the development of endurance, both general and local. Acrobatics (specific volleyball acrobatics), as well as additional sports (which will have a positive transfer for learning techniques), are still present in the training plan and program.
FOURTH STAGE VOLLEYBALL ACADEMY
This stage of volleyball academy includes girls U16 and boys U17. They participate in the leagues of the city, region, province and state. Given the age at this stage, the volleyball school has the following tasks - the systematic development of physical abilities, improvement of technical elements, attention to psychological preparation, higher theoretical work with children (tactics, systems, team composition, game rules and competition propositions). The number of weekly training is 5 times, plus 1 game (within practise or championship). The goal of training and practise is to improve the level of knowledge and skills, with the tendency of further progress in terms of specialization of certain playing positions. For further adoption of the technique, special attention should be given to the specific manifestations of individuals technical elements (style), ie. cultivate “unusualness” . In this period, as far as technique and its manifestation are concerned, they are primarily in competitive conditions, ie in game situations. This also determines the method of training that will be applied, and that is the game method or the situational method.
Regarding physical preparation, it is focused on all motor abilities development, with special emphasis on the development of all specific types of strength and specific volleyball endurance . A certain additional work on these abilities is desirable if there are possibilities for that (fitness, loaded work...). All acrobatic elements should be perfected, with special work on volleyball acrobatics (rolls, dives, “pancake”...).
FIFTH STAGE VOLLEYBALL ACADEMY
Even though some authors do not consider this stage to be part of the learning process, because they think that players development has already finished, it is an acceptable opinion that elementary development in volleyball is over only after this stage. The reason for this is that certain motor abilities are just entering the 2nd critical window of the sensitive phase of accelerated development (especially in boys), meaning that motor abilities are not "mature" to the final extent. This automatically implies that the manifestation of technique is not the same as it will be after the end of this stage. In this stage, girls are U18 and boys U19 years old, and they are competitors - juniors. The tasks of training in this period are as follows - to pay maximum attention to the development of all motor skills, improving technical and tactical elements in-game situations, paying attention to psychological preparation, raise theoretical knowledge to a higher level (tactics concerning our and opposing team, game systems, team composition, rules of the game and competition propositions). The number of weekly training remained unchanged in relation to the previous level, considering that they are school children. If there are no championship matches, training matches or matches within the group should be organized.
The aim of the paper is to adequately prepare children in all areas (technical, tactical, physical, psychological and theoretical preparations), for the transition to the senior team level. Some authors do not consider this transition too problematic, but it should be emphasized that children of this age only look like adults, but they are far from it. Most of the time in training should be dedicated to situational practice, ie to bring the training conditions as close as possible to the game conditions . As far as technique is concerned, maximum technical efficiency and its manifestation in-game situations should be emphasized. In this period, the technique is at a higher level, but in order to raise its efficiency even higher, further training and specialization of certain playing positions in the team are needed. Physical preparation is focused on the development of all motor abilities, with special attention to the development of explosiveness and speed, of all necessary muscle groups . In other words, additional work is necessary, ie work in the gym, loaded work... Acrobatics is still present, with more attention being focused on specific volleyball acrobatics with a ball. During this period, it is not uncommon for individuals to join the senior team training, so it can be said that this stage of volleyball academy is practically the o maximum level of training for the volleyball technique manifestation.
The problem of choosing the method, content and organization of training is of constant interest in both science and practice, and in recent years extensive research has been conducted related to organized physical activity, which would contribute to the optimal development of anthropological characteristics of persons of both sexes and all ages. Human abilities and characteristics can be most successfully developed in the so-called "sensitive phases". These are periods of ontogenesis when the most significant pace of certain abilities development is achieved. Moreover, adaptive possibilities increase and especially favourable preconditions for the formation of certain motor knowledge are created.
In general, observing the volleyball skills learning process, it must be stated that each country, region, city, club, and even coach has its way of training and the system of reaching the skills acquisition. This paper is an attempt to, in a way, establish order, or system in the adoption of volleyball techniques, ie the path of skills development. Starting from certain factors in motor skills learning (growth and motor skills development), the algorithm implies initial learning of some motions and movements that are attainable by everyone, after which motor actions and movements become more complex from stage to stage. Following the completion of youth categories, it could be said that the players mastered the appropriate techniques, through systematic learning. Also, this systematization allows for a safer and more sensitive selection of certain positions in the team, without just relying on coaching experience (with no intention of degrading this important factor).
CONFLICT OF INTEREST
The study was partly supported by the grant III47015 of the Research Council of the Republic of Serbia (2011-2020).
©2021 Sports Academy Belgrade. All rights reserved. Powered by Magma
Publication of this journal is financially supported by the Ministry of Science, Technology and Development Republic of Serbia.