Body composition of English Premier League soccer players: Influence of playing position,international status,and ethnicity

Abstract

Body composition is a key consideration in the physical make-up of professional soccer players. The aims of the present study were to determine whether the body composition of professional soccer players varied according to playing position, international status or ethnicity, and to establish which variables best distinguished the soccer players from a reference group. Body composition was assessed using dual-energy X-ray absorptiometry in 64 male professional soccer players. Measured variables included bone mineral density and the relative amounts of lean and fat mass. Data were analysed using analysis of variance and stepwise discriminant function. The soccer players recorded better values than a reference group (n = 24) for all body composition compartments. Percent lean mass and bone mineral density were the variables best able to identify the soccer players (95.5% correctly classified). Differences in body composition were evident between goalkeepers and outfield players, but not between outfield playing positions. No differences were found on the basis of international status. The non-Caucasian players demonstrated significantly lower percent body fat (9.2 ± 2.0%) than the Caucasian players (10.7 ± 1.8%). It was concluded that body composition is important for elite soccer players, but that homogeneity between players at top professional clubs results in little variation between individuals.     

The Impact of an Obstacle Course Sport Education Season on Students' Aerobic Fitness Levels

Abstract

The purpose of this study was to determine if factor patterns of selected sports skills were similar for two samples, a skilled sample and one consisting of a wide range of skills. Comparisons were also made with kinesiological evidence regarding the patterning of basic sports skills. Data consisting of performance scores on various sports skills were available for 166 high school girls. Out of this sample, a smaller sample was drawn consisting of 69 girls who were above average in skill. Two factor models, alpha and incomplete image analysis, were used in the analysis of this data. The factor pattern of selected sports skills performed by subjects above average in skill was similar in many respects to that of a sample which included a wide range of skill. The primary difference lay in the clustering of overarm skills which appeared in the above-average factor pattern. The overarm and push patterns of the above-average sample resembled the patterns of skill obtained through kinesiological analysis. The structure of kicking, underarm, and sidearm skills remained obscure, based on the results of factor analytic techniques.     

Youth Leaders' Perceptions of Commitment to a Responsibility-Based Physical Activity Program

This study extended Schilling's (2001) study by investigating program commitment among a larger (N = 12), older (M = 16.7 years), and more experienced (M = 5.96 years) sample of participants in the Project Effort Youth Leader Corps. Individual interviews elicited a greater number and specificity of themes. Program-related barriers included logistics, structure, and relationships, and personal-related barriers included perceived alternatives, personal characteristics, and “real-life” responsibilities. Similar to Schilling's (2001) earlier study, antecedents grouped under program environment, program structure, relationships, and personal characteristics. Participants also described outcomes in terms of behavior and emotional involvement but reported more themes related to leadership. Results are discussed in terms of consistencies and changes over time and implications for program development, expansion, and evaluation.     

Optimized versus corrected peak power during friction-braked cycle ergometry in males and females

Abstract

The aim of this study was to compare optimization and correction procedures for the determination of peak power output during friction-loaded cycle ergometry. Ten male and 10 female sports students each performed five 10-s sprints from a stationary start on a Monark 864 basket-loaded ergometer. Resistive loads of 5.0, 6.5, 8.0, 9.5, and 11.0% body weight were administered in a counterbalanced order, with a recovery period of 10 min between sprints. Peak power was greater and occurred earlier, with less work having been done before the attainment of peak power, when the data were corrected to account for the inertial and frictional characteristics of the ergometer. Corrected peak power was independent of resistive load (P > 0.05), whereas uncorrected peak power varied as a quadratic function of load (P < 0.001). For males and females, optimized peak power (971 ± 122 and 668 ± 37 W) was lower (P < 0.01) than either the highest (1074 ± 111 and 754 ± 56 W respectively) or the mean (1007 ± 125 and 701 ± 45 W respectively) of the five values for corrected peak power. Optimized and mean corrected peak power were highly correlated both in males (r = 0.97, P < 0.001) and females (r = 0.96, P < 0.001). The difference between optimized and mean corrected peak power was 37 ± 30 W in males and 33 ± 14 W in females, of which approximately 15 W was due to the correction for frictional losses. We conclude that corrected peak power is independent of resistive load in males and females.     

Variable training: effects on velocity and accuracy in the tennis serve

Abstract

Variable practice has been shown to be an effective strategy to improve open motor skills. However, the usefulness of this procedure in closed motor skills remains controversial. The following study has the objective of analysing the effects of variability practice in the improvement of a closed skill. The skill studied has been the tennis serve. Thirty young tennis players (13 ± 1.52 years), divided in two groups, took part in this study. One group practiced in variable conditions and the other group in consistency conditions. Both groups performed 12 training sessions (60 serves/session). The variable practice group improved their accuracy significantly compared with the consistency group (F_3.25 = 3.078; P = 0.035). The velocity of serve increased after training in both groups (F_3.25 = 15.890; P = 0.001). The practice in variable conditions seems to be effective in improving the performance of the tennis serve.     

Small and Medium-Sized Enterprises in Rural Business Clusters: The Relation Between ICT Adoption and Benefits Derived From Cluster Membership

This study examines the relationships between information and communication technologies (ICT) usage, the benefits a company derives from membership in a rural business cluster, and the success of rural companies. Analysis of 333 rural businesses located in northern lower Michigan showed a strong relationship between (a) ICT adoption and benefits derived from the membership in business clusters, (b) ICT adoption and self-reported business success, and (c) benefits derived from business clusters and business success. Although analysis indicates that these relationships may be industry specific, results suggest that ICT adoption by rural enterprises may have advantages for the region's social capital and business success and may help reduce the digital divide experienced in rural communities.     

Questioning Techniques: A Study of Instructional Practice

To what extent do teachers use questions to encourage deeper thinking and elicit fuller responses? How do teachers use the levels of questions and wait time as a teaching technique? How do teachers make space for students to talk together so that their thoughts are visible to other students? This article seeks to provide answers to these important questions through a review of the literature that begins with a study of the history of questioning, and then turns to the following topics: developing higher level thinking through questioning strategies; the role of wait time within the context of classroom climate and peer interactions; and higher order questioning strategies aligned with student achievement in reading and language arts. Although the author's frame of reference for how these issues play out is within the context of a school where students’ ability to articulate understanding and their own point of view is purposefully promoted and highly valued, the insights will have broad applicability across a full spectrum of schools.     

Factors contributing to mathematical problem-solving performance: An exploratory study

This paper describes differences in mathematical problem-solving performance of third-grade gifted and fifth-grade average students observed during an eight week period. Results indicated that such factors as attitude, motivation, and belief systems were important to performance. In addition there were major differences in problem-solving behavior between the girls and boys in this study. Because these results were incidental to the original questions of the study (Buchanan, 1984), they were deemed especially significant. Four groups, one of third-grade gifted boys, one of third-grade gifted girls, one of average boys and one of fifth-grade average girls met with the experimenter twice a week for eight weeks to solve a variety of mathematical problems. In the global analysis of video tapes of all sessions and post hoc statistical analysis of selected quantifiable variables, differences in problem-solving performance were best described in terms of motivation, beliefs about mathematics, problem-solving strategies, and means of achieving satisfaction. In addition, the girls' groups were more ego-involved and social; they completed fewer problems and had longer solution times than the boys' groups. Further holistic research is needed to describe the complex interaction that occurs during mathematical problem solving in group situations. Then, appropriate intervention might be designed to assure that both boys and girls have an opportunity to perform at optimum levels.     

SIDE-VIEW: Evaluation of a system to develop team players and improve productivity in Internet collaborative learning groups

This paper briefly summarizes the initial development of a computer-supported collaborative learning environment and evaluates its effects in relation to the productivity of CSCL groups. The design of the SIDE-VIEW system is driven by the social identity approach to understanding group behaviour and is premised upon the need to establish congruity between the self-definition of group members and their collaborative learning tasks. We begin by outlining the rationale for the system in relation to productivity and the emergence of team players within collaborative learning groups. We then describe aspects of the design that are intended to enhance both, and report on a field trial of the initial prototype on international groups of higher education students. The preliminary results of the field study indicate that aspects of the design encourage the emergence and influence of team players within groups, with consequential improvements to the quality of the group output. The role of team players in CSCL groups is contrasted with that of group leaders.