LONG-TERM ATHLETE DEVELOPMENT, FROM THEORETICAL AND PRACTICAL MODEL TO COGNITIVE PROBLEM DESARROLLO A LARGO PLAZO DEL DEPORTISTA, DESDE EL MODELO TEÓRICO Y PRÁCTICO HASTA EL PROBLEMA COGNITIVO

Correspondence with the author: Robert Ropret, Е-mail: robert.ropret@dif.bg.ac.rs ABSTRACT Two decades after designing and implementing the course of Children’s sport as a university subject at the Faculty of Sports and Physical Education, University of Belgrade, and its full academic and practical affirmation, the question of revising and expanding the theoretical and practical context of this subject has been raised, especially in the area of knowledge-related to long-term development of an athlete (DRS) and career planning (problem of this paper). Therefore, theoretical and practical models related to DRS have been introduced as the subject of this analysis, and as a function of theoretical and practical verification, related to defining the context of a new cognitive problem. If we summarize the extensive theoretical and practical sources, we can conclude that sport theory is not capable to creating a framework for a realistic, much less a long-term athlete development model, which is why the aim of this paper is to set out the theoretical and empirical trends towards a new paradigm for holistic view of DRS through sport. An essential and thorough analysis of the context of a representative model of long-term development of an athlete, known by its English acronym „LATD and other DRS models ascertained that their starting point should be established around the concept of “physical literacy”, as well as that the truth of the DRS model is still in the process of theoretical and practical verification. The discussion offered is a framework for new strides in approach to a comprehensive theory and practice of sport, especially in the area of children’s and youth sport.


INTRODUCTION
The rich sporting practice together with the numerous results of research, indicate that a child starts playing sports primarily for the purpose of perfecting existing and acquiring new sports skills, as well as for fun and entertainment, socializing and making new friendships, excitement and challenge, achieving success -winning, gaining physical fitness, competitions, pursuing a career towards a higher level (Bačanac, 2011). This, as well as many other and similar statements, considered in relation to the subject of this paper, which is practical and theoretical models of a long-term athlete development as a function of a new cognitive problem, mean that the child's age, in human development, is a period during which many life experiences and values are acquired through participation in sports. Physical exercise and physical activity enrich child's growth, encourage the development of many attributes and capacities without which, among other things, it is not possible to plan, and thus not to move on to the next step in a sports career (Jevtić and Ropret, 2011). According to the subject of this paper, both theory and practice confirm that success in sport comes through the process of planning long-term development.
Sport theory, in a specific way, addresses the issues of the athlete's development and career, while neglecting the holistic context and meaning of learning about-for-through movement and exercise. In some sense, numerous reductions can be observed in both international and, in particular, domestic sources, for which it can be said they are the result of the studious dealing with children's participation in sports. More intensively than participation, the problems of children's growing up through sport are elaborated, such as insufficient participation or premature termination of sports. In understanding both approaches, but primarily aimed at humanizing childhood growing up through sports, the Faculty of Sports and Physical Education of the University of Belgrade has designed the subject Children's sport, which brings professional and scientific facts of children's growing up through sports under its motto "Children's Sport from Practice to Academic Field". One of the areas in the program of this subject are models of child development through sport. Two decades after the creation of Children's sport as a university subject, and its full academic and practical affirmation, the question of theoretical grounding and practical expediency of the existing models of a longterm athlete development, as a cognitive challenge, are addressed in this paper.
The reasons for such a discussion are the mechanistic takeovers of the offered models of longterm athlete development by many national systems of sports, research and pedagogical institutions. This removed or neglected discussions about the authenticity of the models established on theoretical and practical reductions. According to the definition that sees modelling as a method of cognition as a diminished image of the original, it is obvious that the level of abstraction (simplification) of the real system of a long-time development of an athlete has influenced the validity of the offered models. Therefore, it is convenient to question the success of presenting a structurally, organizationally...complex system of human development through sport, through models. Intense debate is conducted through scientific journals of reference and sports practice documents. Summarizing the extensive theoretical and practical material that is the subject of analysis for the purpose of reaching an answer to the subject and problem of this paper, all suggests that sport theory is not (was not) able to create a framework for a realistic, much less a comprehensive, model of long-term athlete development. In other words, it cannot be said for the theoretical and practical models offered that they do not represent a realistic cognitive and practical system, in terms of both the number and relevance of the factors of the structure and the number of facts that could confirm the authenticity of the original and the model. However, and notwithstanding their cognitive integrity, the models offered, as a context for professional and operational planning, have helped trainers and policy makers in development through sport in their mission to help children and young people to develop through sport, to display and value their talent for sport. On the other hand, an insufficiently productive system of work in sports can encourage children to leave sports, have injuries and spend their talent. Accordingly, the aim of this paper is to propose some important answers in order to move toward a theoretical paradigm for a holistic view of a long-standing level through sport. and economically. Each of the stages of LTAD is clearly defined in terms of motor, cognitive and psychosocial development (Balyi, 2001): 1. Development of basic skills (boys 6-9, girls 5-8 years of age) -the development of abilities and skills through fun and play: ABC of sport (agility, balance, coordination, speed), RTJ (running, throwing, jumping), KGBS (kinesthetic, gliding, buoyancy, striking with the body) and CPK (catching, passing, kicking) 2. Training study (boys 9-12, girls 8-11 years of age) -the development of abilities through exercises of directed, semi-specific and specific character. The ratio of training and competition is 70:30%. It is considered the key phase in coordination development. 3. Training abilities (girls 11-14, boys 12-15 years of age) -Individualization of training, adaptation of training to different levels of maturity. The ratio of training and competition is 60:40% 4. Training for competition (boys 15-18, girls 14-17 years of age) -Intensifying the training load. Individualization towards sport, position in the team, competitive discipline. The ratio of training and competition with trainings of competition-specific content is 40:60% 5. Training for winning (18 plus years of age) -Achieving physiological genetic capacity. The ratio of training and competition with trainings of competition-specific content is 25:75%.
Transition to the next career level involves mastering the previous level program tasks (planning and coaching -learning with outcomes). The aim of each DRS model is to enable the gradual development and attainment of a given level of an athlete without the negative consequences of early specialization, injury and leaving the sport through work appropriate to the age characteristics of a child. One of the objective physiological parameters the basis of which the monitoring, adaptation and evaluation of programs according to the individual characteristics of the individual, i.e. the individualization of the program, is based on the dynamics of growth parameters (peak body height -PBH and peak body mass -PBM). The DRS model, which is operational today but also disputed at the same time, is based on the following postulates (Balyi & Hamilton, 2004): • The minimum of 10 years of age or 10,000 hours to achieve the elite athlete level (Bloom, 1985;

LONG-TERM ATHLETE DEVELOPMENT MODEL -THEORETICAL AND PRACTICAL CONTROVERSY AND/OR A NEW COGNITIVE PARADIGM
Design and implementation of the long-term athlete development model -DRS is not a new professional step. However, one of the existing models, known by its English acronym -LTAD (Longterm Athlete Development -LTAD), affirmed by Istvan Balyi, seems to dominate this period of development of sport. It was initially set up as a development program for the Canadian Olympic team of alpine skiers. Since its initial draft, it has quickly evolved into a generally accepted development-planning model for young athletes in a wide variety of sports. It has been accepted by a number of other national systems, including Canada, USA, UK, Ireland, Australia, New Zealand and others. In the next steps towards the development of this model, the original context has been redefined and supplemented by the results of the psychologist Andreas Ericsson's research (Ericsson, Krampe & Tesch-Rome, 1993;Ericsson, 2006Ericsson, , 2008. According to Balyi and Hamilton (Balyi & Hamilton, 2004) the original model is a 'framework' that is adapted and organized according to the parameters of the child's growth and development. Established on the deductible principles of age (chronological, biological, anatomical, sports) and attributes of growth and development, LTAD is made as a multistage progressive model (6 to 8 levels) depending on the sport branch. The division into levels was in the first step organized around two-year periods of chronological age (of two years' time, from six to 18 years of age), and then continued through periods until the end of the active sports career, that is, through optional periods of lifelong practice in various forms of sport. Subsequent elaborations of the model and its application in other sports, the first stages are summarized into segments of three years of chronological age (6-9, 9-12, 12-15, and 15-18), that is, with continuing one's career at the age of 18 and older. The task of the DRS model is to enable the development of basic motor skills in their optimal phase of physical development, based on the assumption that basic motor skills are adopted and that the young athlete performs the same effectively  (Ford et al., 2011) criticize the DRS model as too one-dimensional, indicating the lack of empirical evidence on which the model is based. These authors suggest, "Interpretations of the model are limited because the data on which they are based rely on questionable assumptions and errors of cognition methods. " In addition, they suggest that DRS perceives a generic model, not an individualized athlete development plan.

THEORETICAL REDUCTIONS IN LONG-TERM ATHLETE DEVELOPMENT MODELING
One of the weaknesses of the Theory of sport derives from its one-sided view of learning in sport. Namely, it is dominated only by motor learning represented through two phases. The first is aimed at forming a general motor base, and the second at training and competitions in a given sports field. Obviously, this reduction in Theory of sport is also found in athlete development models! The same is reflected in a one-sided approach to setting the context of learning about-for-through movement, but also in understanding the fact that sport changes the nature of the child, both in the motor, as well as in the social, cognitive, affective space. It is possible that this reduction in the Theory of sport was deliberate and incurred due to the need for coaches to illuminate only one learning space of a child. The reduction can also be the result of insufficient integrity of the sports sciences and its disciplines. However, Theory of sport can be said to deviate from one of its own principles regarding the non-linear nature of developmental motor skills and capacities that determine success in sport. The epilogue is that sport theory itself does not affirm the importance and share of physical activity, exercise and sport in the development of a child, that it ignores or does not recognize the importance of sensory-motor stimulation in the development of be established to encourage the development of other aspects of the child development (integral development of a child). Therefore, there is clearly an intra-theoretical and inter-theoretical dissonance, as well as a "crack" in the transfer of the results of research studies into the practice of sports and physical education! Because of the above, it is important to set properly the DRS model and to establish its mission towards "physical literacy" as a pedagogical outcome of participation in sport. From the DRS perspective, "physical literacy" is an outcome that describes the mastery of (motor) knowledge that is undoubtedly a precondition for adopting and effectively performing multipurpose movements that are contained in the specificities of sports fields and disciplines (Kirk & Rhodes, 2010).
The theory of sport recognizes the first phase of motor development as a period during which a large number of children become involved in mastering the challenges of some of the sports offered, but also as a period in motor development during which a high degree of so-called dropouts is registered. Dropping out of sports due to the actions of factors of different origins, among which there are various forms of abuse registered. In other words, for most children, this phase is also the end of participation in one of the started sports or sports in general, whereby not only questions about the mastery of motor skills are imposed prior to "dropping out of sports" but, above all, motor competence for lifelong learning, exercise and an active lifestyle. Equally important is the answer to the question of mastery of skills, development of abilities, and the acquisition of habits and skills that would facilitate the participation of a child in another sport (the resulting orientation of children's sports in the function of DRS). In support of this are the data from a study conducted by the US Olympic Committee, which indicated that most US Olympians, from the end of the 20 th century, participated in a number of sports before the final selection of sports in which they achieved success at the Olympic Games. The ratio of 88:12% in male athletes was found in favour of a number of sports or, as stated, 88% of athletes had tried one of the sports before participating in the main sport. This ratio for girls is 83:17%. A total of 97% of OG participants believe that participation in multiple sports was very important for later career success (Gibbons, Hill, McConnell, Forster & Moore, 2002) abstract thinking, which, along with social learning, affects the intellectual development (conditionally does not recognize Piaget's theory on intellectual development).
Staying within the space of this reduction, it should be emphasized that the goal of the first stage in the child's motor development is to "try out in sports" and to master the skills and habits of the motor, cognitive, social, affective space. The outcome of this phase could be expressed by the outcome of "physical literacy" 1) , which essentially contains motivation, confidence, physical abilities, knowledge and understanding to evaluate and participate in physical activity . Philosophically, the term "physical literacy" encompasses the affective, physical, and cognitive characteristics of human nature, whereby focusing on only one of the characteristics of development would not constitute "physical literacy" . On the personal plane of the child, "physical literacy" has value in nurturing and affirming those (personal) abilities and skills that have the potential to enhance and enrich the quality of childhood growth and biopsycho-social maturation without which we would not be able to develop as human beings and act in accordance with our other possibilities (Almond, 2013).
For the analysis of the problem of this paper, it is interesting that the theory of physical education recognizes the acquisition of motor competence, which is positively associated with health benefits, preferences and habits for the lifelong exercise. However, in pursuit of these goals, physical education theory itself relies on and affirms content from selected sports, neglects the motor, methodical and organizational complexity and inappropriateness of the same to a heterogeneous group of students, thus unnecessarily complicating or delaying the process of holistic literacy through this subject. Contrary to the theories mentioned above, the results of scientific research clearly indicate that progress towards the outcomes of the first phase of motor learning, in a human and child-oriented theory of sport, should 1) "Physical literacy" represents the pedagogical concept directed towards adoption of basic skills in movement and the basic sports skills that provide a child with self-confidence and control in the wide range of physical activities, rhythmical (dance) and other situations in life. "Physical literacy" involves the ability of recognizing the environment, as well as activities and reactions adequate to situation (Higgs, Balyi, Way, Cardinal, Norris & Bluechardt, 2008) The conclusion is imposed that sport theory is not clearly profiled in the space of a child's growing up through sport, that it is enclosed in the principles and rules relating to adult sport, that it ignores the attributes, needs and rights of the child to transition through sport on the path of development for life.

PRACTICAL REDUCTIONS IN LONG-TERM ATHLETE DEVELOPMENT MODELING
By summarizing sports knowledge, defining goals and objectives, content and outcomes of children's growing up and participation in sports, DRS is presented in the professional literature as a model of the development program that takes place through certain stages. The reason for the formation of the DRS model, which is described by stages and periods, from what is called "trial" to "embodiment" and involvement in sport (acquisition phase), through development performance (developmental phase of acquired attributes) leading to top performance in sport (training and competitive perfection) is an attempt to have a comprehensive view of the factors of development of an athlete, as well as to make the development program in a systematic and planned manner. Many researchers have dealt with the problem how to reach a top athlete level, how to maintain that level (an elite athlete) and what the key attributes for achieving success are (Bloom 1985;Lazlo 1986;Stambulova, 1994;Salmela, 1994;Voronzov, 1998;Platonov, 1999;Wyllemand & Lavallee, 2004). By forming certain theoretical generalizations on this issue, the authors created models based on the principles of developing training careers. Depending on the author, the development from a beginner to a top athlete takes place through a number of stages, starting from the minimum of three phases (initial, development, perfection), through five (preparatory, specialization start, intensive training in the chosen sport, culmination phase, phase of discontinuity in training), up to seven (active start and fun, basics phase; learning about training; competition training; winning training, top level maintenance, lifelong involvement in sports). For some authors, up to 10 stages in the development model can be observed from the beginning to the top result and its maintenance. Regardless of the number of stages in the development model, citation, and authority of the authors themselves, it can be concluded that in all the cited and analysed studies, there are searches for the answer to one of two questions that are dominant, namely the talent of the athlete and the transition of the athlete's career. When this approach is considered in relation to Schlossberg's transition theory (Schlossberg, 1981), then all the above authors can be said to have established the deduced and generalized models of DRS solely on the theory and practice from the space of transition and career, i.e. they were unilateral in their empirical and theoretical work because they neglected the remaining three constituents of Schlozberg's theory (situation, self and support). In other words, it could be accepted that one of the sources of the practical and theoretical reductions of DRS mentioned lies in insufficient interdisciplinary and multidisciplinary recognition and collaboration.
The analysed DRS models, when viewed in their orientation towards achieving results in elite sport, two approaches can be distinguished, one realized through early specialization and dominance of specific training aids, or, the other, which indicates that success arrives through a variety of training methods and tools. The model through early specialization occurs in technically complex sports in which superior performance can be reached even before full physical maturity (sports and rhythmic gymnastics, figure skating, diving). In contrast, the model through a variety of activities and focused play are more common in sports where elite performance is achieved after full maturity (swimming, track and field, martial arts, sports games and others). In this model, specialization occurs between the ages of 13 and 15, while the specific training and training aimed at achieving maximum abilities is conducted after the age of 16 (Coutinho et al., 2016).
In the context of this discussion, it is important to cite the DRS model that should be established around the concept of "physical literacy" and which is developed as a lifelong value from the age of the new-born (from birth to the age of four); childhood (from five to eleven years of age); adolescence (eleven to eighteen years of age); early adulthood (eighteen to 30 years of age); maturity (30-65 years of age) to older age (65 +).
The DRS athlete models are made based on cognitive psychology and theory of motor skills learning. Accordingly, there are two approaches to organizing knowledge acquisition (Ericsson, 1993 • deliberate practice, which represents highly structured activities with clear specific goals toward the development of ability, hard training, low levels of fun and a high level of concentration, dedication, motivation; • deliberate play that supports intrinsically motivated activities based on the affective aspect of exercise. The concept of the deliberate practice leads to early specialization, focusing on only one sport and activities that directly mimic the means and methods of elite sport training, and with the expectation that young athletes, early involved in a large amount of specific work, thus build the chances of developing into an elite level athlete. Early guidance and specialization are usually characterized by content without any enjoyment or fun. The consequences of this approach can have a negative effect on motivation, psychological and physical fatigue, injury and giving up further exercise (Baker, 2003 The model analysis indicates that few authors have provided a comprehensive cognitive model of DRS, which would be established around the facts that a given concept can be applied to in a given sport. There are also no clear parameters the basis of which the assessment of progress and progress itself can be evaluated on the attribute scale and the scale of sports competence. As a result, early specialization is often misinterpreted and equalled to the deliberate practice while early diversity is equalled to the deliberate play. In theory, these concepts are clearly demarcated and may be in interaction (coexistence).
Development athlete models have achieved their application through various forms of the planned development of an athlete, from beginner to elite result. Based on the analysis of a number of papers (Bloom, 1985;Salmela, 1994;Stambulov, 1994 , we have identified two main concepts that can be presented as two sub models, namely one concerning the development of talent and transition of talents. The talent development sub-model is a multistage, progressive construct that describes changes in the development of athletes. Bailey and Morley (2006) state that the same must be a multidimensional form that incorporates influences of interpersonal, intrapersonal, cognitive and creative abilities. The same authors cite the lack of information relating to the quantification of the components of each phase as a weakness, and that many components are difficult or almost impossible to test.

CONCEPTUAL MODELS OF LONG-TERM ATHLETE DEVELOPMENT
Conceptual models emerge because of recognition of a clear structure, logic of functioning of a practical and theoretical system. They are also structural models because they indicate the structure of the system and, as such, are adapted as a means of communication within the profession. Recent significant conceptual models of athlete development cited in the literature are the following: The CTM model, unlike the previous ones, clearly links the cause-and-effect relationships in processes, influence on outcomes, as well as key elements in five-level transition processes.
For these concepts and models of athlete development, the greatest challenge for researchers is to determine the criteria that define an elite athlete, his or her development, the degree of his / her achievement, and the characteristics that need to be developed and monitored. By clearly defining these parameters, different interpretations and problems in comparison would be avoided.

Theoretical and practical speculations on truthfulness of the LTAD principle
Challenges to the reality of the LTAD program functioning are the most numerous in the area of lack of scientific research and evidence based on longitudinal studies that would confirm statements about periods of susceptibility and their association with age. The aforementioned disadvantages limit the validity of LTAD. Claims about psychological and social characteristics at particular ages and their association with success in sport are based on theoretical considerations without concrete evidence (Tucker, 2013). Bailey et al. (2010) indicated that the conclusions about the periods of susceptibility ("windows") were empirical and that there was no exact, solid, experimental evidence. The authors of the model, Balyi and Hamilton (Balyi & Hamilton, 2004) personally confirmed that their work is the result of empirical observations. Much earlier, Beunen and Malina (Beunen & Malina, 1996) pointed to evident variations in the development of motor skills depending on the degree of growth and development, but there was clearly no clarity on the role of the type and level of stimuli on their changes. Claims that susceptibility periods have a definite duration (beginning and end) and that missed stages are irreplaceable are also questionable because the successes of those who were later engaged in sports speak against such attitudes (Viru, Loko, Harro, Volver, Laaneots & Viru, 1999; Van Kooten, 2016). The relevance of these views is confirmed by the results of a survey of 1720 US Olympians who show that the average age at entry into sport is 11.4 years (Riewald, 2014) The lack of acceptable methods of quantifying training, paediatric data, the breadth of applied stimuli for a very wide range of different sports hinders the ability to accurately investigate the effect of stimuli for the developmental of abilities, and in connection with the degree of growth and development (Ford et al., 2011).
The results of certain studies on these issues are contradictory. One speaks of the "skill barrier", that is, progress in development toward specialization and specific skills depends on basic motor patterns developed at an early age (Gallahue & Ozmun, 1998;Gallahue & Donnelly, 2003). Second, they do not support views on the conditionality of developmental ability and the degree of growth and development.
From a neurological point of view, research indicates that brain mass reaches its peak development in infancy (Rabinowicz, 1986) and that periods from 6-8 and 10-12 years of age coincide with periods of development of motor skills ( Rowland, 1997; have not demonstrated a direct relationship between aerobic endurance development and susceptibility periods. Most indicators of aerobic endurance development are related to body size, mass development and body composition. The periods of susceptibility to velocity development have also remained without concrete evidence despite numerous studies (Beunen & Malina, 1996;Butterfield, Lehnhard, Lee & Coladarci, 2004). Changes in velocity have been found to occur but are related to biological, neural and biomechanical factors that can be associated with both age and maturation.
The problem of the objective existence of susceptibility stages for the development of strength has been addressed by several researchers (Pfeiffer & Francis, 1986;; Lillegard, Brown, Wilson, Henderson & Lewis, 1997), of which only one paper  has indicated a significant increase strength in the post-puberty period (16.8 years of age) compared to the pre-puberty period (10.5 years of age).
Measurements of muscular strength indicated that training has the effect of improving strength by increasing muscle mass and muscle synchronization (Beunen & Malina, 1988), but without evidence of association of development with age. The conclusion of Ford et al. (Ford et al., 2011) is that the assumptions on which LTAD is based upon are speculative and unfortunately without any empirical evidence.

Challenges for verification and validation of the concept of ten thousand hours of training
One of the first postulates of LTAD is that 10,000 hours of sports training, or 10 years (20 hours a week) are required to succeed in sports and to reach the elite level. The rule emerged from a study by Ericsson et al. (1993) on the association between the success of violin students at the Berlin Academy and the average volume of 10,000 hours of practice up to the age of 20. Research in the field of sports (Bloom, 1985;Ericsson & Charness, 1994) has indicated that it takes 8 to 12 years to train talented athletes to reach the elite athlete level. Data from the US Olympic Committee points out that it takes 13 years of training to get results on the level of participation in the Olympic team, and 15 years to win the Olympic medal. The 10,000-hour coaching rule has become widely accepted in almost all models and variations of the LTAD model. Criticism of the 10,000-hour postulate referred to insufficient scientific and experimental evidence of the data, and that this volume of work did not necessarily lead to the elite level in sports. Ericsson and Pool (Ericcsson & Pool, 2016) explained the criticism expressed, pointing out that a survey conducted on violin students in 1993, who are still not elite musicians but only successful students, and that elite musicians are in their 30s and with 20-25,000 hours of exercise; that these are average results; that it is not about any exercise but high intensity work with high motivation and concentration; that anyone who trains 10,000 hours is not expected to reach the level of an elite athlete, and that the assumption about the greater importance of deliberate training of 10,000 hours in relation to genetic predispositions is wrong. According to Erikson, the 10,000 hours rule was misinterpreted, it was not related to sports skills, and, in that sense, was not scientifically proven. It was accepted because it "seemed magical, respectable, with a round figure According to Tucker (Tucker, 2013), a significant drawback of the LTAD model is that it does not take into account those who are delayed in development, so that the 10,000-hour principle is unrealistic.

Learning technique through large scope and low intensity
One of the LTAD model postulates is to focus on the development of techniques and general motor skills in the first stages (9-12 and 12-15 years of age), i.e. "physical literacy" instead of competitive results. Practice has shown that a coach focusing on the result causes an increase in the intensity of training, which results in neglect of technique, and higher intensity leads to an increased possibility of injury, overtraining, "mental burnout", giving up (Lang & Light, 2010). no significant differences; the Australian model is with a larger range of scopes: for the first phase, it envisages a weekly range of 6 -17.5 km and a British 8 -16 km per week. For the second phase, the volumes are partly different, the Australian recommends 14-36 km and the British 24-32 km (Lang & Light, 2010). The authors conclude that it is probably a mistake either that the trainers apply too much volume or that they did not integrate the technique exercises into the training.

The relationship of training and competition
The criticisms of the LTAD model implementation also apply to the extent of competition, discipline and age of competitors. One example is the British Swimming Association (ASA) program. Bill Sweetenham, Director of the British Swimming Federation, criticized national programs based on the LTAD model for the large number of competitions (12) and the inadequate number of training sessions (Affolter, 2016). The ASA lowered the minimum age for state competitions to 10 years of age for girls and 11 for boys, excluded races at 50 and 100 m from the program, and introduced 200m race. Subsequently, disciplines 800m and 1500 m were introduced for girls of 11 and boys of 12 years of age. The reason for these changes is "the lack of physical development required to swim properly in a sprint" (Grange & Gordon, 2004). According to some authors (Brandon, 2002;Maglischo, 2003) competitions in 200 m sections are more stressful than in the case of sprints in shorter sections.
In the analysis of the Judo Canada NCCP Committee, Van Kooten (2016) presents the inconsistencies of the Judo LTAD program: 88% of Olympic and world medal winners started this sport at the age of 11, which means they "skipped" phase 2 (the most important one) of the program. The program prescribes that those younger than 12 years of age should avoid "specialization", "negative competitive experiences", "being compared to other children", and well as all activities should be in the "form of play and fun". Therefore, it is surprising to find the recommendation of the program that the A7 and A9 children should learn specific throwing techniques as well as pass competitions on the club level.
Unfortunately, misinterpretation of LTAD recommendations that volume and not the intensity of training load is important at an early age has led to the development of inappropriate work programs and recommendations. Guided by the emphasis on volume rather than training intensity, the ASA (Amateur Swimming Association -UK) recommended coaches that athletes should, in the second phase of the program (9-12 years of age), swim about 8000 meters per week. Coaches, concentrating on this task as and due to lack of training time, neglected practicing technique (Moore, Collins & Burwitz, 1998;ASA, 2003).
Multiple researchers indicate that the misapplication of high-volume training has the effect of reducing the volume of technique training and neglecting the fact that the basic technique is taught at lower movement speeds ( state that a high volume of low intensity training, aimed at the development of aerobic abilities, has little effect on activities lasting from 20 seconds to 5 minutes. Most competitive disciplines (80%) in swimming do not last more than 5 minutes and call into question the usefulness of this type of training.
According to research by Lang and Light (Lang & Light, 2010), coaches believe that the LTAD guideline for building swimmers through long-distance training can impede the development of athletes talented for shorter disciplines. Researchers agree that in order to advance in development, the quality of exercise is more important than the quantity of work ( Comparing the training volume of the different systems (UK and Australia) indicates that there are Other postulates of LTAD exposed to critics Coaches and parents are an indispensable factor in implementing the LTAD model. Black and Holt (Black & Holt, 2009), as well as Lang and Light (Lang & Light, 2010), have found that the LTAD program provides a national framework for structuring talent development systems. However, one cannot speak of wider acceptance and implementation of the LTAD principle, except as a general strategy. Banack et al. (Banack, Bloom & Falcao, 2012) indicate that, in addition to considering the positive aspect that everyone "speaks the same language", less experienced young coaches and parents of beginners have positive attitudes towards LTAD, while more experienced coaches have some reservations about the model and that largely adhere to personal experience. Coaches who work with younger children up to 9 years of age (basic phase) agree with the program principles, while older coaches show the aforementioned reservations towards the model.
In addition, the problem of fulfilling the principles of sports development is the imperative of the environment for coaches to achieve results from an early age, which causes children who are delayed in development to be neglected in the process of training and selection. Black and Holt (Black & Holt, 2009) find that coaches do not accept the LTAD model due to lack of information and education on its implementation. Insufficient education and training of coaches are shown in ignorance of the principles of selection, selection of tests and criteria that, if any, are different from club to club and beyond. A significant drawback was the linkage between the systems at the club, regional and national levels.
In realizing the principle that success in (pre) adolescence is not the primary task, the problem arises that many coaches are guided by the traditional approach that success (a medal) at an early age is the only measure and evidence of talent. For this approach, justification is found in the sports culture tradition of most nations (Lang, 2009; and in the previous, personal experience from most coaches ( It is obvious that the implementation of LTAD is influenced by poor education of trainers and poor knowledge in the field of importance for quality work. Rowley (1994) points out that 85% of football coaches do not use any research tools to identify talent. Coaches should be educated on how to use the data required by LTAD model.

CONCLUSION
I The analysis of the current long-term athlete development models shows that, in spite of the progress in knowledge, the theory and practice display significant differences in approach to this problem. The lack of longitudinal research, insufficiently elaborated system of monitoring, control and evaluation of an athlete influences the credibility of the offered long-term development models. One of them, LTAD, was created as the leading guideline in the development of an individual in accordance with his/her biological, motoric, cognitive and psychosocial characteristics.
II Despite its widespread implementation, however, little is known about the effects of applying the LTAD model in the context of an individual case. From the moment of its implementation to date, approaches have been identified which affirm but also challenge it. A large number of determinants, primarily individual dynamics and non-linearity of the bio motor development of the child-athlete, require a longitudinal approach to knowledge in relation to the practice of exploring time-dependent series of assessment of individual abilities. In other words, it is necessary to create a cognitive system that would verify individual and inter-individual differences in adaptations of the trained attributes of the athlete within the specificity of a given sport branch. The lack of theoretical and practical context of individual sports branches is imposed as a limiting factor in the verification of the theoretical and practical importance of LTAD. • Terms and then stages of susceptibility in motor development of the child-athlete. Research has shown no relevant evidence of this stage, while some studies have also challenged their credibility; • Claims on the amount of training required to reach the level of an elite athlete. They have been challenged for applying an inadequate methodology, suspicion of speculation in conclusions that athletes with less workload reach the desired level; • Recommendation on the advantage of the training load versus intensity. Misunderstandings about specificity of certain motor abilities are evident.
IV The perceived shortcomings of this and other DRS models stem from the inadequacy in operational planning of the implementation that arises and due to the (absence of) knowledge of the coach about the characteristics of the development of a child, working methods, principles and methods of selection, and thus did not offer an orientation of practice in: (1) work with children who later enter the puberty phase later, (2) work with children who enter the sport at a later age; V The LTAD model is always asked questions such as a) What are the factors that, in the listed circumstances, make it possible to acquire basic skills and habits from the motor, cognitive, social, and affective space ("physical literacy") and which are key to further progress? b) Whether the individual's talent, influence of another sport or daily physical activity in the environment ("family sport", "backyard sport") affect "physical literacy" and creation of the performance relevant to continuation of a career and potential success in elite sport.
VI With a comprehensive analysis of the context of LTAD and other DRS models, it is noted that their starting point must be established around the concept of "physical literacy".
VII There are various theoretical and practical approaches around "physical literacy" to determine its being, significance and modality of development. What is concrete refers to the non-formal course of its acquisition during which children gain the first high-quality skills, abilities, habits, develop character, affirm their talent. In contrast, there are modalities of directional activity carried out in physical education and sports clubs (formal system). The non-formal belongs to the unique process of acquiring "physical literacy" as the outcome of a development phase after which the following phases are planned (acquisition, development of specific attributes, training and competitive magnificence) within one of the DRS models.
VIII The truthfulness of the DRS model is still in the process of theoretical and practical verification. The discussion offered is a framework for new strides in the approach to comprehensive theory and practice of children's and youth sports.