In this chapter, we discuss research regarding ATDEs in youth sport and practical implications – both grounded in the holistic ecological approach (HEA). By ecological, we mean the focus on the athletes' environment that affects their development; holistic refers to a view of the environment as a complex and dynamic whole that consists of multiple interrelated settings, levels and domains (13, 14).

We begin with the model of Effective Talent Identification and Development Procedures by Martindale and colleagues (15) that was developed based on interviews with experienced coaches about successful ATDEs' contributions to the development of young athletes. The model formed the basis of the Talent Development Environment Questionnaire, TDEQ (7), that measures five features of an environment that fosters talent development: (a) long-term aims and methods; (b) wide-ranging and coherent messages and support; (c) emphasis on talent development rather than early selection; (d) individualised and ongoing development; and (e) an integrated and holistic system. The TDEQ and a subsequent revised version, TDEQ5 (16), have been used to gauge strengths and weaknesses of specific ATDEs to assist efforts to improve environments (e.g., 17). The instrument was further used to investigate associations between features of ATDEs and athletes' development. Although the various modifications of the structure warrant caution, research has demonstrated that athletes' favourable perception of their ATDE was linked positively to the satisfaction of their basic needs, mental toughness and wellbeing (18, 19) and negatively associated with burnout (20, 21).

We now move to the holistic ecological approach (HEA) that offers a case study (qualitative) approach to investigating the structure, culture and inner workings of ATDEs that have had varying degrees of success in helping athletes to make the junior-to-senior transition (14). To aid case studies, two working models (8) were created by taking inspiration from ecological psychology, systems theory and cultural psychology (22–24). Figure 1 presents the ATDE working model as a framework for describing the roles and functions of the different components and relations within an environment. The prospective young elite athletes appear at the centre of the model, and other ATDE's components are structured into two levels (micro and macro) and two domains (athletic and non-athletic). The micro level refers to the environment in which the prospective elite athletes spend a good deal of their daily lives. The macro level refers to social settings, which affect but do not contain the athletes, as well as to the values and customs of the cultures to which the athletes belong. The athletic domain covers the part of the athletes' environment that is directly related to sport, whereas the non-athletic domain presents all the other spheres of the athletes' lives. The outer layer of the model represents the past, present and future of the ATDE, emphasising that the environment is dynamic.

The Environment Success Factors (ESF) working model (Figure 2) predicts that the ATDE's success is a result of the interplay between preconditions, processes, individual and team development and achievements, with organisational culture serving to integrate these elements.

The model's starting point is the environment's preconditions (e.g., human, material and financial), all of which are necessary but not sufficient for success. The model then illustrates how the daily processes (e.g., training, camps and competitions) lead to three outcomes: athletes' individual development and achievements (e.g., psychosocial and athletic skills), team achievements and organisational development and culture. Organisational culture (25) is central to the ESF model and consists of: cultural artefacts (e.g., stories, customs and physical manifestations such as clothing and organisation charts), espoused values (i.e., principles, goals and standards that the organisation shows to the world) and basic assumptions (i.e., taken for granted and serving as underlying reasons for actions). Key basic assumptions are integrated into a cultural paradigm, guiding the socialisation of new members and providing stability. Organisational culture is seen as an integrative factor of the ADTE's effectiveness in helping talented young athletes to develop into senior elite athletes (14). Broadly speaking, successful ATDEs are environments that promote athletes' wellbeing and long-term athletic and personal development (12).

The HEA models have been tested and empirically validated through in-depth and real-time case studies of successful ATDEs. Examples of these studies include (but are not limited to) the Danish national 49er sailing team (8), a Swedish track and field club (9), a Norwegian kayak team situated in an elite sport high school (10), soccer academies across Europe (26–29), two handball clubs in Denmark and Norway (30) and a world-class trampoline environment in Canada (31). In contrast, one study was focused on a less successful golf environment in Denmark (32). Further, cross-case comparisons (33) allowed us to conclude that even though all environments are unique (no two environments are ever the same), successful ATDEs employ many of the same principles in their work. These principles were implemented in different ways, and some environments compensated for a weakness in one feature by a strong presence of another. Thus, the uniqueness of each environment was expressed in how they implemented the common principles. In Table 1, we summarise the shared features of ATDEs, providing descriptions of their positive (research based) and opposite poles (inferred logically or grounded in the study of the less successful environment). The shared features fall within two overall categories related to the structure and the culture of the environment.

To continue with shared features, a recent scoping review of ATDEs (12) covered 44 studies published mainly during the last decade. In the analysis of the studies, the authors focused on positive (wellbeing, long-term athletic and personal development) and less positive (illbeing, limited athletic and personal development) talent development outcomes and related functional and dysfunctional features of ATDEs. Such an explicitly holistic definition of environment success is a welcome addition to the original literature that defined success as a track record of developing elite athletes but found that successful environment did in fact promote holistic development (11). The features were further sorted into four categories with clear connections to the ESF model (see Figure 2 and Table 1): preconditions, organisational culture, integration of efforts and quality holistic preparation. To provide a glimpse into the authors' preliminary conceptual framework, on the functional side, preconditions include skilled staff, accessible role models and system-wide support; organisational culture is characterised by an empowering climate, psychological safety and coherent and lived values; integration of efforts includes social relationships outside of sport and collaboration among stakeholders; and quality holistic preparation focuses on holistic personal development and long-term athletic preparation. On the dysfunctional side, examples of corresponding features refer to limited and unskilled staff, lack of role models and facilities, promoting winning at all costs, isolation and lack of stakeholder collaboration, lack of interest in the athletes as persons and inhibited preparation. The authors conclude that ATDEs weighted in favour of the functional features (and compensating for or eliminating dysfunctional ones) will provide positive outcomes in regard to athletes' wellbeing and athletic and personal development.

A holistic and ecological outlook has clear implications for practitioners. Coaches and talent development managers are encouraged to look beyond their training sessions and take an interest in providing a whole environment that is conducive for the athletes' development. Related to the structure of the environment, coaches might coordinate training camps and intense training periods with school exam periods, deliberately recruit and support role models, ensure communication within athletes' micro-environments (e.g., club, academy and national team training) and promote supportive training groups. In relation to organisational culture, coaches can acknowledge their role as cultural leaders (34), strive to develop a cohesive culture, stimulate athletes' free initiatives and maintain a long-term development focus. Sport psychology consultants are encouraged to conduct their interventions inside the athletes' natural settings and aim to optimise not only an athlete's individual psychological skills but the entire environment.

As HEA has gained popularity, the approach has found its way into new but related domains of research. Zooming in on the ATDE's macro level, a case study in Danish swimming (35) and subsequent case studies in multiple sports (36) examined the successful collaboration in talent development management between a federation, a municipality and a local club, termed “an organisational triangle”. This research demonstrated that successful interorganisational collaboration in talent development required a shared philosophy and collaborative decisions, which allowed for coherent actions that would eventually lead to outcomes beneficial for the local athletes/clubs.

The next expansion of HEA has been its application in the study of Dual Career Development Environments (DCDEs) supporting athletes' efforts in combining their competitive careers with education or work. Seven case studies of successful DCDEs were conducted within the European Project “Ecology of Dual Careers” (37) based on adapted versions of the original ATDE and ESF models (38, 39). The further cross-case analysis led to the identification of ten essential features of DCDEs, such as a dedicated DC support team, integration of efforts, mentorship and access to expert support as characteristics of a holistic DCDE structure. Whole person and empowerment approaches, flexible solutions, care of mental health and a proactive approach to the development of the environment further described the shared dual career philosophy (40).

The most recent research project explored the nature of underserved athletic talent development environments (UATDE). An exploration of the career pathways of ten American professional athletes with low socioeconomic backgrounds highlighted the challenging circumstances they had to overcome to achieve athletic success and how their time in a UATDE had lasting ramifications in their lives (41). An interview study with stakeholders working in or with athletes from UATDEs unearthed specific challenges faced in UATDEs and demonstrated how developing within such environments impacted athletes even after they reached the college and professional levels of sports (42). Finally, a case study applied the HEA as a lens to examine a specific UATDE in basketball (43) with adapted versions of the original HEA models used to guide data collection. This research demonstrated that operation of the UATDE was significantly influenced by the underserved community in which it was embedded and that the team's roster comprised athletically talented but psychosocially vulnerable players, requiring the support team to expend considerable resources in supporting the psychosocial development of their players. Nevertheless, the UATDE managed to support the athletes in making a successful transition to a professional career and a better life because of a small but dedicated support team and a cultural paradigm that set the person before the performer and catered to the athletes' needs beyond the basketball court, and which was carefully maintained by the head coach as a cultural leader.