The influence of` preseason training phase and training load on body composition and its relationship with physical qualities in professional junior rugby league players

ABSTRACT

This study investigated changes in body composition in relation to training load determined using RPE and duration (sRPE), and its relationship with physical qualities over a preseason period. Sixteen professional academy players (age = 17.2 ± 0.7 years; stature = 179.9 ± 4.9 cm; body mass = 88.5 ± 10.1 kg) participated in the study. Body composition was assessed before and after each training phase and physical qualities assessed at the start and end of preseason. Across the whole preseason period, skinfold thickness, body fat percentage and fat mass were most likely lower (ES = ?0.73 to ?1.00), and fat free mass and lean mass were likely to most likely higher (ES = 0.31 to 0.40). Results indicated that the magnitude of change appeared phase-dependent (ES = ?0.05 to ?0.85) and demonstrated large individual variability. Changes in physical qualities ranged from unclear to most likely (ES = ?0.50 to 0.64). Small to moderate correlations were observed between changes in body composition, and TL with changes in physical qualities. This study suggests training phase and TL can influence a player’s body composition; that large inter-participant variability exists; and that body composition and TL are related to the change in physical qualities.     

Validity Evidence of an Electronic Portfolio for Preservice Teachers

This study applied Messick's unified, multifaceted concept of construct validity to an electronic portfolio system used in a teacher education program. The subjects included 128 preservice teachers who recently completed their final portfolio reviews and student teaching experiences. Four of Messick's six facets of validity were investigated for the portfolio in this study, along with a discussion of the remaining facets examined in two previous studies. The evidence provided support for the substantive and generalizability aspects of validity, and limited support for the content, structural, external, and consequential aspects of validity. It was suggested that the electronic portfolio may be used as one requirement for certification purposes, but may not be valid for the purpose of assessing teacher competencies .     

Is it wrong to play violent video games?

Many people have a strong intuition that there is something morallyobjectionable about playing violent video games, particularly withincreases in the number of people who are playing them and the games'alleged contribution to some highly publicized crimes. In this paper,I use the framework of utilitarian, deontological, and virtue ethicaltheories to analyze the possibility that there might be some philosophicalfoundation for these intuitions. I raise the broader question of whetheror not participating in authentic simulations of immoral acts in generalis wrong. I argue that neither the utilitarian, nor the Kantian hassubstantial objections to violent game playing, although they offersome important insights into playing games in general and what it ismorally to be a ``good sport.' The Aristotelian, however, has a plausibleand intuitive way to protest participation in authentic simulations ofviolent acts in terms of character: engaging in simulated immoral actserodes one's character and makes it more difficult for one to live afulfilled eudaimonic life.     

Individual Differences in the Stability and Change of Childhood Depression: A Growth Mixture Model With Structured Residuals

Studies of developmental trajectories of depression are important for understanding depression etiology. Existing studies have been limited by short time frames and no studies have explored a key factor: differential patterns of responding to life events. This article introduces a novel analytic technique, growth mixture modeling with structured residuals, to examine the course of youth depression in a large, prospective cohort (N = 11,641, ages 4–16.5, 96% White). Age-specific critical points were identified at ages 8 and 13 where depression symptoms spiked for a minority of children. Most depression risk was due to dynamic responses to environmental events, drawn not from a small pool of persistently depressed children, but a larger pool of children who varied across higher and lower symptom levels.     

A Twin and Adoption Study of Reading Achievement: Exploration of Shared-Environmental and Gene-Environment-Interaction Effects

Existing behavior-genetic research implicates substantial influence of heredity and modest influence of shared environment on reading achievement and reading disability. Applying DeFries-Fulker analysis to a combined sample of twins and adoptees (N = 4,886, including 266 reading-disabled probands), the present study replicates prior findings of considerable heritability for both reading achievement and reading disability. A simple biometric model adequately described parent and offspring data (combined N = 9,430 parents and offspring) across differing types of families present in the sample Analyses yielded a high heritability estimate (around 0.70) and a negligible shared-environmentality estimate for both reading achievement and reading disability. No evidence of gene × environment interaction was found for parental reading ability and parental educational attainment, the two moderators analyzed.     

The effect of normal load force and roughness on the dynamic traction developed at the shoe–surface interface in tennis

During tennis-specific movements, such as accelerating and side stepping, the dynamic traction provided by the shoe–surface combination plays an important role in the injury risk and performance of the player. Acrylic hard court tennis surfaces have been reported to have increased injury occurrence, partly caused by increased traction that developed at the shoe–surface interface. Often mechanical test methods used for the testing and categorisation of playing surfaces do not tend to simulate loads occurring during participation on the surface, and thus are unlikely to predict the human response to the surface. A traction testing device, discussed in this paper, has been used to mechanically measure the dynamic traction force between the shoe and the surface under a range of normal loading conditions that are relevant to real-life play. Acrylic hard court tennis surfaces generally have a rough surface topography, due to their sand and acrylic paint mixed top coating. Surface micro-roughness will influence the friction mechanisms present during viscoelastic contacts, as found in footwear–surface interactions. This paper aims to further understand the influence micro-roughness and normal force has on the dynamic traction that develops at the shoe–surface interface on acrylic hard court tennis surfaces. The micro-roughness and traction of a controlled set of acrylic hard court tennis surfaces have been measured. The relationships between micro-roughness, normal force, and traction force are discussed.     

Relationships between computational thinking and the quality of computer programs

Education and Information Technologies - Computational thinking – the ability to reformulate and solve problems in ways that can be undertaken by computers – has been heralded as a...     

Recruiting,Funding, and Hiring of Doctoral Students in Physical Education Teacher Education

ABSTRACT

This article examines trends and issues surrounding recruiting, funding, and hiring of doctoral physical education teacher education (D-PETE) students and graduates. Sources for this examination were background data collected by Boyce and her colleagues, the existing literature on these topics, and qualitative data gathered from 30 sport pedagogists during one round-table session at the National Association for Kinesiology in Higher Education (NAKHE) conference in January 2015. All three sources indicated the importance of recruiting and funding of students and hiring of graduates to the future of D-PETE programs. A number of paths were identified which sport pedagogists could follow in order to keep D-PETE programs safe and help them flourish. Unfortunately, agreement as to which of these paths the field should take was often in short supply. In the conclusions section, suggestions for future research of recruiting, funding, and hiring are made with the goal of providing data which could lead to sport pedagogists making more informed decisions regarding the future direction of D-PETE.