Dynamics of attacker–defender dyads in Association Football : parameters influencing decision-making

Previous work on pattern-forming dynamics of team sports has investigated sub-phases of basketball and rugby union by focussing on one-versus-one (1v1) attacker-defender dyads. This body of work has identified the role of candidate control parameters, interpersonal distance and relative velocity, in predicting the outcomes of team player interactions. These two control parameters have been described as functioning in a nested relationship where relative velocity between players comes to the fore within a critical range of interpersonal distance. The critical influence of constraints on the intentionality of player behaviour has also been identified through the study of 1v1 attacker-defender dyads. This thesis draws from previous work adopting an ecological dynamics approach, which encompasses both Dynamical Systems Theory and Ecological Psychology concepts, to describe attacker-defender interactions in 1v1 dyads in association football. Twelve male youth association football players (average age 15.3 ± 0.5 yrs) performed as both attackers and defenders in 1v1 dyads in three field positions in an experimental manipulation of the proximity to goal and the role of players. Player and ball motion was tracked using TACTO 8.0 software (Fernandes & Caixinha, 2003) to produce two-dimensional (2D) trajectories of players and the ball on the ground. Significant differences were found for player-to-ball interactions depending on proximity to goal manipulations, indicating how key reference points in the environment such as the location of the goal may act as a constraint that shapes decision-making behaviour. Results also revealed that interpersonal distance and relative velocity alone were insufficient for accurately predicting the outcome of a dyad in association football. Instead, combined values of interpersonal distance, ball-to-defender distance, attacker-to-ball distance, attacker-to-ball relative velocity and relative angles were found to indicate the state of dyad outcomes

Collaborative testing in Sport and Exercise Degrees: A comparison of first and third year students\u27 perceptions

Collaborative testing is recognised as an effective assessment approach linked to positive student outcomes including enhanced test performance and reduced assessment anxiety. While collaborative testing approaches appear beneficial to university students in general, it is unclear whether students from different year levels benefit to the same extent. Therefore, the overarching aim of this study was to compare the perceptions and performances of first and third- year undergraduate students taking part in collaborative testing on multiple occasions during a semester. It was predicted that first-year students would perceive the collaborative testing opportunities as more beneficial than third-years given their limited formative experiences with university assessment. Further, it was expected that students would generally perform at a higher level on collaborative versus individual tests in line with previous work. Student performance and perceptions of collaborative testing were collected on two occasions within a semester over a period of two years in both a first-year and third-year course. Quantitative and qualitative results revealed that first-year students were more receptive and perceived more benefits relating to collaborative testing than third-years despite the fact both cohorts generally performed at a higher standard on the collaborative versus individual components. These findings suggest that while collaborative testing is considered beneficial to most, if not all, students, the benefits appear to be greater for first-year student cohorts

The dynamics of expertise acquisition in sport : the role of affective learning design

Objectives: The aim of this position paper is to discuss the role of affect in designing learning experiences to enhance expertise acquisition in sport. The design of learning environments and athlete development programmes are predicated on the successful sampling and simulation of competitive performance conditions during practice. This premise is captured by the concept of representative learning design, founded on an ecological dynamics approach to developing skill in sport, and based on the individual-environment relationship. In this paper we discuss how the effective development of expertise in sport could be enhanced by the consideration of affective constraints in the representative design of learning experiences. Conclusions: Based on previous theoretical modelling and practical examples we delineate two key principles of Affective Learning Design: (i) the design of emotion-laden learning experiences that effectively simulate the constraints of performance environments in sport; (ii) recognising individualised emotional and coordination tendencies that are associated with different periods of learning. Considering the role of affect in learning environments has clear implications for how sport psychologists, athletes and coaches might collaborate to enhance the acquisition of expertise in sport.</p

Differential regulation of β2-adrenoceptor and adenosine A2B receptor signalling by GRK and arrestin proteins in arterial smooth muscle

Generation of cAMP through Gs-coupled G protein-coupled receptor (GPCR) [e.g. β2-adrenoceptor (β2AR), adenosine A2B receptor (A2BR)] activation, induces arterial smooth muscle relaxation, counteracting the actions of vasoconstrictors. Gs-coupled GPCR signalling is regulated by G protein-coupled receptor kinases (GRK) and arrestin proteins, and dysregulation of Gs/GPCR signalling is thought play a role in the development of hypertension, which may be a consequence of enhanced GRK2 and/or arrestin expression. However, despite numerous studies indicating that β2AR and A2BR can be substrates for GRK/arrestin proteins, currently little is known regarding GRK/arrestin regulation of these endogenous receptors in arterial smooth muscle. Here, endogenous GRK isoenzymes and arrestin proteins were selectively depleted using RNA-interference in rat arterial smooth muscle cells (RASM) and the consequences of this for β2AR- and A2BR-mediated adenylyl cyclase (AC) signalling were determined by assessing cAMP accumulation. GRK2 or GRK5 depletion enhanced and prolonged β2AR/AC signalling, while combined deletion of GRK2/5 has an additive effect. Conversely, activation of AC by A2BR was regulated by GRK5, but not GRK2. β2AR desensitization was attenuated following combined GRK2/GRK5 knockdown, but not by depletion of individual GRKs, arrestins, or by inhibiting PKA. Arrestin3 (but not arrestin2) depletion enhanced A2BR-AC signalling and attenuated A2BR desensitization, while β2AR-AC signalling was regulated by both arrestin isoforms. This study provides a first demonstration of how different complements of GRK and arrestin proteins contribute to the regulation of signalling and desensitization of these important receptors mediating vasodilator responses in arterial smooth muscle

Affective learning design: A principled approach to emotion in learning

This PhD project set out to explore the role of emotion during learning in sport, focusing on how actions, emotions and cognitions interact under the influence of constraints. Key outcomes include the development of the theoretical concept - Affective Learning Design, and a new tool for assessing the intensity of emotions during learning - the Sport Learning and Emotions Questionnaire. The findings presented in this thesis provide both theoretical and practical implications discussing why emotion should be considered in the design of learning environments in sport

Issues and challenges in developing representative tasks in sport

"About the Book Understanding and developing expertise is an important concern for any researcher or practitioner working in elite or high performance sport. Whether it's identifying talented young athletes or developing methods for integrating cutting-edge sport science into daily coaching practice, scientists, coaches and researchers all need to understand the skills, characteristics, and knowledge that distinguish the expert performer in sport. The Routledge Handbook of Sport Expertise is the first book to offer a comprehensive overview of current research and practice in the emerging field of sports expertise. Adopting a multi-disciplinary, multi-faceted approach, the book offers in-depth discussion of methodological and philosophical issues in sport expertise, as well as the characteristics that describe sporting ‘experts’ and how they can be facilitated and developed. Exploring research, theory and practice, the book also examines how scientists and practitioners can work together to improve the delivery of applied sport science. With contributions from many of the world’s leading researchers in expertise and skill acquisition in sport, the Routledge Handbook of Sport Expertise is important reading for any advanced student, researcher, coach or sport science support officer looking to better understand this cutting-edge topic. "--Publisher websit

Olympic and Paralympic coach perspectives on effective skill acquisition support and coach development

The role of skill acquisition specialists within sport systems has become more prominent and imbedded in daily training environments with coaches; however, literature pertaining to their role and contributions to effective coach development is very scant. The objective was to extend our understanding of the coaches’ perception of the role of, and relationship with, a skill acquisition specialist to identify key factors of effective support that shape coach behavior and ultimately enhance athlete performance. Semi-structured interviews with two National coaches with experience and podium success in multiple Olympic/Paralympic Games, Commonwealth Games, and World Championships was conducted. Three distinct narratives were identified: representing various experiences of the coaches in their sport (‘the unplanned journey’), their relationship with the skill acquisition specialist (‘more than just a skill expert’), and how this impacted athletes’ development (‘keys to success’). As part of the relationship development process, aspects of coaches’ philosophy were challenged. In addition, the skill acquisition specialists had to display a wide range of skills in the pursuit of shaping coaching behaviors that could further enhance athletes’ performance. Required skills included, but were not limited to, bridging the gap between scientific literature and practical application, ensuring knowledge was logical and aligned with the specific needs of the coach and cultural context, demonstrating trust and accountability, displaying personal and social skills and an ability to engage athletes and obtain their approval. Crucially, while overlapping themes occurred, the skill specialists needed to be adaptable to each unique working relationship and this emerged over time

Using the principle of scaling to improve skill acquisition and the overall sporting experience in children’s sport

The notion of scaling, as it applies to junior sport, suggests that variables such as equipment, playing area, and rules should ideally be matched to the capabilities of the child. This chapter provides a discussion of the importance of scaling in children’s sport and the potential links between scaling, backyard games, and drop-out from junior competitions. A summary of the results from research is included to provide the reader with an overview of the typical approaches that have been employed to investigate the effects of scaling, and to also highlight the specific benefits of scaling that have been reported in the research. The final sections focus upon the need for a principled approach towards scaling characterised by the application of a theoretical framework to underpin the implementation of scaling in research and practical contexts. Considerations for practitioners are provided to help guide the application of scaling by sporting associations

Taekwondo fighting in training does not simulate the affective and cognitive demands of competition : Implications for behavior and transfer

[Extract] Enhancing practice design is critical to facilitate transfer of learning. Considerable research has focused on the role of perceptual information in practice simulation, yet has neglected how affect and cognition are shaped by practice environments and whether this influences the fidelity of behavior (Headrick et al., 2015). This study filled this gap by examining the fidelity of individual (cognition, affect, and actions) and interpersonal behavior of 10 highly skilled Australian Taekwondo athletes fighting in training compared to competition. Interpersonal behavior was assessed by tracking location coordinates to analyze distance-time coordination tendencies of the fighter–fighter system. Individual actions were assessed through notational analysis and approximate entropy calculations of coordinate data to quantify the (un)predictability of movement displacement. Affect and cognition were assessed with mixed-methods that included perceptual scales measuring anxiety, arousal, and mental effort, and post-fight video-facilitated confrontational interviews to explore how affect and cognitions might differ. Quantitative differences were assessed with mixed models and dependent t-tests. Results reveal that individual and interpersonal behavior differed between training and competition. In training, individuals attacked less (d = 0.81, p < 0.05), initiated attacks from further away (d = -0.20, p < 0.05) and displayed more predictable movement trajectories (d = 0.84, p < 0.05). In training, fighters had lower anxiety (d = -1.26, p < 0.05), arousal (d = -1.07, p < 0.05), and mental effort (d = -0.77, p < 0.05). These results were accompanied by changes in interpersonal behavior, with larger interpersonal distances generated by the fighter–fighter system in training (d = 0.80, p < 0.05). Qualitative data revealed the emergence of cognitions and affect specific to the training environment, such as reductions in pressure, arousal, and mental challenge. Findings highlight the specificity of performer–environment interactions. Fighting in training affords reduced affective and cognitive demands and a decrease in action fidelity compared to competition. In addition to sampling information, representative practice needs to consider modeling the cognitions and affect of competition to enhance transfer