Development of dribbling in talented youth soccer players aged 12–19 years: A longitudinal study

Abstract

The aims of the current study were to assess the development and determine the underlying mechanisms of sprinting and dribbling needed to compete at the highest level in youth soccer. Talented soccer players aged 12–19 years (n = 267) were measured on a yearly basis in a longitudinal study over 7 years, resulting in 519 measurements. Two field tests, the Shuttle Sprint and Dribble Test and the Slalom Sprint and Dribble Test, were assessed. Anthropometric characteristics, years of soccer experience, and duration of practice were recorded. The longitudinal data were analysed with multi-level modelling. Comparing the two tests at baseline, low correlations were observed (sprinting: r = 0.49; dribbling: r = 0.22), indicating that each test measures distinct qualities (acceleration vs. agility). Low-to-moderate correlations were found between dribbling and sprinting within each test (Shuttle Sprint and Dribble Test: r = 0.54; Slalom Sprint and Dribble Test: r = 0.38). Both dribbling and sprinting improved with age, especially from ages 12 to 14, but the tempo of development was different. From ages 14 to 16, sprinting improved rapidly in contrast to dribbling; this was especially evident on the Slalom Sprint and Dribble Test. In contrast, after age 16 dribbling improved considerably but sprinting hardly improved. Besides age, the factors that contribute to dribbling performance are lean body mass, hours of practice, and playing position.     

Personal and situational factors influencing coaches’ perceptions ofstress

Abstract

Coaching has been recognised as a demanding occupation, associated with a range of stressors. The extent to which coaches perceive stress is likely to be influenced by various personal and situational factors. The purpose of this study was to identify coaches' levels of perceived stress and examine the personal and situational factors that may influence coaches' perceptions of stress. In total, 502 coaches working with university, college, Canada Games, and/or nationally identified athletes completed this study. Coaches completed an online survey, which included questions regarding demographics, work/job-related considerations, and aspects relating to their contract. Coaches also completed the Perceived Stress Scale (Cohen, Kamarck, & Mermelstein, 1983 Cohen, S., Kamarck, T. and Mermelstein, R. 1983. A global measure of perceived stress. Journal of Health and Social Behavior, 24: 385–396. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Overall coaches indicated slightly below average levels of perceived stress (M = 15.13 out of 40) compared with norm-values (Cohen & Janicki-Deverts, 2012 Cohen, S. and Janicki-Deverts, D. 2012. Who's stressed? Distributions of psychological stress in the United States in probability samples from 1983, 2006, and 2009. Journal of Applied Social Psychology, 42: 1320–1334. [Crossref], [Web of Science ®] , [Google Scholar]). Demographic factors, job-related characteristics, and certain aspects of their contract were associated with coaches' perceptions of stress. In particular, unclear expectations, long-working hours (>40), lack of agreed evaluation criteria, higher salaries, and a lack of social support were related to higher perceptions of stress. As such, the findings of the current study indicate that a reduction in perceived stress is likely to be achieved through a multifaceted approach that addresses multiple factors associated with coaching.     

Deaf persons of asian american, Hispanic american, and african american backgrounds: a study of intraindividual diversity and identity

This article explores the ways in which deaf college students who are members of minority racial groups think about and describe their identities. In-depth, semistructured interviews with 33 deaf students of Asian American, Hispanic American, and African American background were analyzed for themes regarding the self-reported identities of respondents. Results suggest that each person is a constellation of many parts, some of which are stronger than others but any of which can be drawn out in response to a particular set of circumstances, resulting in a contextual and interactive model of identity. Four factors are described as central to this "intraindividual" model: individual characteristics, situational conditions, social conditions, and societal conditions. Additionally, the model includes a biographical component reflected in changes in identity that occur over time. Findings are discussed as they relate to identity theory. The article is concluded with recommendations for further research, as well as considerations for educators and counselors of deaf minority students.     

Attachment and Emotion Regulation during Mother-Teen Problem Solving: A Control Theory Analysis

We present a control theory analysis of adolescents' attachment strategies in the Adult Attachment Interview (AAI). In Study 1, Q-sort prototypes for secure/anxious and deactivating/hyperactivating strategies were used to differentiate between Main and Goldwyn's AAI classifications. In Study 2, we examined how AAI strategies were associated with emotion regulation during mother-teen problem solving. 4 aspects of mother-teen problem solving (dysfunctional anger, support/validation, avoidance of problem solving, and maternal dominance) were used to predict teens' AAI strategies. Teens with secure strategies engaged in problem-solving discussions characterized by less dysfunctional anger and less avoidance of problem solving. In addition, attachment security showed a curvilinear relation with maternal dominance, indicating that secure teens maintained balanced assertiveness with their mothers. Teens with deactivating strategies engaged in problem-solving interactions characterized by higher levels of maternal dominance and dysfunctional anger. The contribution of attachment strategies to teens' autonomy and to transformations in mother-teen relationships is discussed.     

Effects of whey protein in carbohydrate-electrolyte drinks on post-exercise rehydration

The purpose of this study was to examine the effects of different amounts of whey protein in carbohydrate–electrolyte (CE) drinks on post-exercise rehydration. Ten males completed 5 trials in a randomised cross-over design. A 4-h recovery was applied after a 60-min run at 65% VO_2peak in each trial. During recovery, the participants ingested a high-carbohydrate CE drink (CE-H), a low-carbohydrate CE drink (CE-L), a high-whey-protein (33?g·L^?1) CE drink (CW-H), a medium-whey-protein (22?g·L^?1) CE drink (CW-M) or a low-whey-protein (15?g·L^?1) CE drink (CW-L) in a volume equivalent to 150% of their body mass (BM) loss. The drinks were provided in six equal boluses and consumed by the participants within 150?min in each trial. After exercise, a BM loss of 2.15%?±?0.05% was achieved. Urine production was less in the CW-M and CW-H trials during recovery, which induced a greater fluid retention in the CW-M (51.0%?±?5.7%) and CW-H (55.4%?±?3.8%) trials than in any other trial (p?p?p?p??1 in the current study.     

Post-activation potentiation (PAP) in endurance sports: A review

While there is strong support of the usefulness of post-activation potentiation (PAP) phenomenon in power demanding sports, the role that PAP could play in endurance sports has received less attention. The aim of this review is to present evidence for a better understanding of PAP in endurance athletes; and to discuss the physiological basis and methodological aspects necessary for better practices and designing further studies. A search for relevant articles on PAP and endurance trained athletes was carried out using Medline and ISI Web of Knowledge databases. Twenty-two studies were included in the review. The current evidence suggests the possible influence of PAP for performance enhancement after appropriate conditioning activities during warm up. Evaluation of PAP responses during testing, training and competition may be also important for athletes monitoring. There are many unresolved questions about the optimum load parameters for benefiting from PAP in both training and competition; and the role that PAP may exert for optimal performance while interacting with central and peripheral factors associated with muscle fatigue. Further studies should elucidate the association between PAP responses and long-term adaptations in endurance athletes.     

A systematic review on the deployment and effectiveness of data analytics in higher education to improve student outcomes

Abstract

This is a systematic review conducted of primary research literature published between 2007 and 2018 on the deployment and effectiveness of data analytics in higher education to improve student outcomes. We took a methodological approach to searching databases; appraising and synthesising results against predefined criteria. We reviewed research on the effectiveness of three differentiated forms of data analytics: learning, academic and learner analytics. Student outcomes are defined as retention, academic performance and engagement. Our results find that three quarters of studies report the use of educational data analytics to be effective in improving student outcomes but their relationship with student outcomes requires further and more robust investigation and assessment. We argue that research must interpret and communicate effectiveness qualitatively, as well as quantitatively, by including the student voice in assessments of impact.