The relative contribution of training intensity and duration to daily measures of training load in professional rugby league and union

ABSTRACT

This study examined the relative contribution of exercise duration and intensity to team-sport athlete’s training load. Male, professional rugby league (n = 10) and union (n = 22) players were monitored over 6- and 52-week training periods, respectively. Whole-session (load) and per-minute (intensity) metrics were monitored (league: session rating of perceived exertion training load [sRPE-TL], individualised training impulse, total distance, BodyLoad?; union: sRPE-TL, total distance, high-speed running distance, PlayerLoad?). Separate principal component analyses were conducted on the load and intensity measures to consolidate raw data into principal components (PC, k = 4). The first load PC captured 70% and 74% of the total variance in the rugby league and rugby union datasets, respectively. Multiple linear regression subsequently revealed that session duration explained 73% and 57% of the variance in first load PC, respectively, while the four intensity PCs explained an additional 24% and 34%, respectively. Across two professional rugby training programmes, the majority of the variability in training load measures was explained by session duration (~60–70%), while a smaller proportion was explained by session intensity (~30%). When modelling the training load, training intensity and duration should be disaggregated to better account for their between-session variability.     

Concurrent and longitudinal neuropsychological contributors to written language expression in first and second grade students

The primary purpose of this study was to examine several key questions related to the neuropsychological contributors to early written language. First, can we develop an empirical measurement model that encompasses many of the neuropsychological components that have been deemed as important to the development of written language? Second, once derived, will the neuropsychological components of this model remain stable over first and second grades or will the model change in its composition? Third, will the strength of the relationships between neuropsychological components and writing outcomes be constant over time, or will the strength of the relationships change over time? Finally, will the derived empirical model show significant concurrent and predictive relationships with written expression? The sample included 205 first grade students recruited from a single school district who were followed into the second grade via two cohorts: Measures were aligned with major neuropsychological components as extracted from theoretical models of written expression and available empirical findings examining the neuropsychological contributors to writing in children. These domains included fine-motor speed, language, short-term memory, long-term memory, and various attention/executive functions including working memory. Confirmatory factor analyses (CFAs) and longitudinal structural equation modeling (SEM) methods documented that three core latent traits were present and stable at both grades 1 and 2: Fine-Motor, Language, and Attention/Executive Functions. The overall model was highly related to written expression and spelling at both grades 1 and 2, with the first grade latent traits accounting for 52 and 55% of the variance in second grade written expression and spelling, respectively. At both grades, the Language and Attention/Executive Functions latent traits were more highly associated with written expression and spelling than the Fine-Motor latent trait.     

Social studies: incorporating all children using community and cultural universals as the centerpiece

This article features an elementary teacher who has worked with the authors for the past 10 years in research on building a classroom community and using cultural universals as the centerpiece for elementary social studies for all children. Cultural universals are basic human needs and social experiences found in all societies, past and present, and include food, shelter, clothing, transportation, communication, family living, money, childhood, government, and so on. Actions related to cultural universals are experienced by all children regardless of their cultures, socioeconomic backgrounds, achievement levels, or special needs, so teachers can connect to these experiences as bases for developing historical, geographic, political, economic, sociological, psychological, or anthropological understandings. The ultimate goal is connected knowledge about how the social system works, how and why it developed over time, how and why it varies across locations and cultures, and what all this might mean for personal, social, and civic decision making.     

Electronic detection of dielectrophoretic forces exerted on particles flowing over interdigitated electrodes

Dielectric particles flowing through a microfluidic channel over a set of coplanar electrodes can be simultaneously capacitively detected and dielectrophoretically (DEP) actuated when the high (1.45 GHz) and low (100 kHz–20 MHz) frequency electromagnetic fields are concurrently applied through the same set of electrodes. Assuming a simple model in which the only forces acting upon the particles are apparent gravity, hydrodynamic lift, DEP force, and fluid drag, actuated particle trajectories can be obtained as numerical solutions of the equations of motion. Numerically calculated changes of particle elevations resulting from the actuation simulated in this way agree with the corresponding elevation changes estimated from the electronic signatures generated by the experimentally actuated particles. This verifies the model and confirms the correlation between the DEP force and the electronic signature profile. It follows that the electronic signatures can be used to quantify the actuation that the dielectric particle experiences as it traverses the electrode region. Using this principle, particles with different dielectric properties can be effectively identified based exclusively on their signature profile. This approach was used to differentiate viable from non-viable yeast cells (Saccharomyces cerevisiae).     

Elementary social studies textbooks

Recent criticisms of textbooks have included accusations of favoring breadth over depth, dry writing, lack of context, failure to integrate minority groups, and overillustration. Social studies texts have, in addition, been criticized for meaning-less content, unclear goals, inadequate explanation, separation of knowledge from skills, and other failings. The authors of this article have specified other common faults. As a corrective, they suggests a return to the notion of developing curricula as means to accomplish major goals phrased in terms of intended student outcomes, and aligning social studies instruction with major social education goals.     

A Short Run: Australian Sports History on the 40th Anniversary of the Biennial Sporting Traditions Conference

Abstract

The 40th anniversary of the biennial Sporting Traditions Conference provides a timely opportunity to examine the health of sports history in Australia. This paper identifies three methods through which we can take the temperature of the field and judge its wellbeing. Usually neglected, the first approach is to explore the teaching of sports history in Australia. The second is an analysis of the individuals who have presented to the 21 Sporting Traditions conferences held since 1977 and the content of their papers. The third method is to consider the impact of research in Australian sports history through citations and the other methods used by the Commonwealth of Australia to judge research quality. All three methods support the conclusion that after 40 years sports history’s future in Australia remains far from secure.     

Relative age and maturation selection biases in academy football

ABSTRACT

This study examined the simultaneous effects of relative age and biological maturity status upon player selection in an English professional soccer academy. A total of 202 players from the U9 to U16 age groups, over an eight-year period (total of 566 observations), had their relative age (birth quarter) and biological maturity (categorised as late, on-time or early maturing based upon the Khamis-Roche method of percentage of predicted adult height at time of observation) recorded. Players born in the first birth quarter of the year (54.8%) were over-represented across all age groups. A selection bias towards players advanced in maturity status for chronological age emerged in U12 players and increased with age; 0% of players in the U15 and U16 age group were categorised as late maturing. A clear maturity selection bias for early maturing players was, however, only apparent when the least conservative criterion for estimating maturity status was applied (53.8% early and 1.9% late maturing in the U16 age group). Professional football academies need to recognise relative age and maturation as independent constructs that exist and operate independently. Thus, separate strategies should perhaps be designed to address the respective selection biases, to better identify, retain and develop players.     

Towards a critical sport heritage: implications for sport tourism

ABSTRACT

This paper reflects upon the development and increased acceptance for heritage becoming a key component of sport tourism research. The original sport heritage typology, as posited by Ramshaw and Gammon [2005, More than just Nostalgia? Exploring the heritage/sport tourism nexus. Journal of Sport & Tourism, 10(4), 229–241], is re-examined through a more critical lens, revealing additional dimensions that help augment its key components. More specifically, it is argued that future studies should consider the more intangible features of sport heritage, as well as acknowledging the expanding global nature of sport and its impact upon fandom. Also, the case is made for research to explore the dissonance inherent in much of sports heritage, as well as determining where the power lies in allocating and championing current sport heritages. Lastly, the more general implications to the field of sport tourism are offered with particular regard to motivation, place, and consumption.     

Maturity-associated variation in sport-specific skills of youth soccer players aged 13-15 years

The aim of this study was to estimate the contribution of experience, body size and maturity status to variation in sport-specific skills of adolescent soccer players. The participants were 69 players aged 13.2-15.1 years from three clubs that competed in the highest division for their age group. Height and body mass were measured and stage of pubic hair development was assessed at clinical examination. Years of experience in football was obtained at interview. Six football skill tests were administered: ball control with the body, ball control with the head, dribbling with a pass, dribbling speed, shooting accuracy and passing accuracy. Multiple linear regression analysis was used to estimate the relative contributions of age, stage of sexual maturity, height, body mass and years of formal training in soccer to the six skill tests. Age, experience, body size and stage of puberty contributed significantly but in different combinations to the variance in four of the six skill tests: dribbling with a pass (21%; age, stage of maturity), ball control with the head (14%; stage of maturity, height, body height x body mass interaction), ball control with the body (13%; stage of maturity, years of training) and shooting accuracy (8%; stage of maturity, height; borderline significance, P = 0.06). There were no significant predictors for the tests of dribbling speed and passing accuracy. In conclusion, age, experience, body size and stage of puberty contributed relatively little to variation in performance in four of the six soccer-specific skill tests in adolescent footballers aged 13-15 years.