Anthropometric, speed and endurance characteristics of English academy soccer players: Do they influence obtaining a professional contract at 18 years of age

This study evaluated the anthropometric, speed and endurance characteristics of English academy soccer players, comparing players who obtained a ‘professional’ contract at 18 years old with those that did not (‘academy’); 443 male academy soccer players from an English professional club undertook anthropometric (height and body mass), speed (10 and 20 m sprint) and endurance (Yo-Yo intermittent endurance test level 2 [Yo-Yo]) assessments between 2005 and 2012. Significant improvements with age were found for speed and endurance at each annual age group up until U18 age category. Significant differences were only observed between ‘professional’ and ‘academy’ players for 10 m (p = 0.003, η2 = 0.01) and 20 m (p = 0.001, η2 = 0.01) speed at U16 and U18 and Yo-Yo performance (p = 0.001, η2 = 0.12) at U18 age category. Practitioners should use speed and endurance assessments for monitoring physical development of players rather than for talent identification purposes

A sex difference in the response of the rodent postsynaptic density to synGAP haploinsufficiency

SynGAP is a postsynaptic density (PSD) protein that binds to PDZ domains of the scaffold protein PSD-95. We previously reported that heterozygous deletion of Syngap1 in mice is correlated with increased steady-state levels of other key PSD proteins that bind PSD-95, although the level of PSD-95 remains constant (Walkup et al., 2016). For example, the ratio to PSD-95 of Transmembrane AMPA-Receptor-associated Proteins (TARPs), which mediate binding of AMPA-type glutamate receptors to PSD-95, was increased in young Syngap1+/- mice. Here we show that only females and not males show a highly significant correlation between an increase in TARP and a decrease in synGAP in the PSDs of Syngap1+/- rodents. The data reveal a sex difference in the adaptation of the PSD scaffold to synGAP haploinsufficiency

Are Habitual Hydration Strategies of Female Rugby League Players Sufficient to Maintain Fluid Balance and Blood Sodium Concentration During Training and Match-Play? A Research Note From the Field.

Limited data exists on the hydration status of female athletes, with no data available on female rugby players. The objective of this study was to investigate the habitual hydration status on arrival, sweat loss, fluid intake, sweat Na loss and blood [Na] during field training and match-play in ten international female rugby league players. Urine osmolality on arrival to match-play (382 ± 302 mOsmol·kg) and training (667 ± 260 mOsmol·kg) was indicative of euhydration. Players experienced a body mass loss of 0.50 ± 0.45 and 0.56 ± 0.53% during match-play and training respectively. During match-play players consumed 1.21 ± 0.43 kg of fluid and had a sweat loss of 1.54 ± 0.48 kg. During training players consumed 1.07 ± 0.90 kg of fluid, in comparison to 1.25 ± 0.83 kg of sweat loss. Blood [Na] was well regulated ([INCREMENT]-0.7 ± 3.4 and [INCREMENT]-0.4 ± 2.6 mmol·L) despite sweat [Na] of 47.8 ± 5.7 and 47.2 ± 6.3 mmol·L during match-play and training. The findings of this study show mean blood [Na] appears to be well regulated despite losses of Na in sweat and electrolyte free fluid consumption. For the duration of the study players did not experience a body mass loss (dehydration >2%) indicative of a reduction in exercise performance, thus habitual hydration strategies appear adequate. Practitioners should evaluation the habitual hydration status of athletes to determine if interventions above habitual strategies are warranted

Anthropometric and three-compartment body composition differences between super league and championship rugby league players: Considerations for the 2015 season and beyond

Super League (SL) and Championship (RLC) rugby league players will compete against each other in 2015 and beyond. To identify possible discrepancies, this study compared the anthropometric profile and body composition of current SL (full-time professional) and RLC (part-time semi-professional) players using dual-energy X-ray absorptiometry (DXA). A cross-sectional design involved DXA scans on 67 SL (n=29 backs, n=38 forwards) and 46 RLC (n=20 backs, n=26 forwards) players during preseason. A one-way ANOVA was used to compare age, stature, body mass, soft tissue fat percentage, bone mineral content (BMC), total and regional (i.e., arms, legs and trunk) fat and lean mass between SL forwards, SL backs, RLC forwards and RLC backs. No significant differences in age, stature or body mass were observed. SL forwards and backs had relatively less soft tissue fat (17.5 ± 3.7 and 14.8 ± 3.6 vs. 21.4 ± 4.3 and 20.8 ± 3.8%), greater BMC (4,528 ± 443 and 4,230 ± 447 vs. 4,302 ± 393 and 3,971 ± 280 g), greater trunk lean mass (37.3 ± 3.0 and 35.3 ± 3.8 vs. 34.9 ± 32.3 and 32.3 ± 2.6 kg) and less trunk fat mass (8.5 ± 2.7 and 6.2 ± 2.1 vs. 10.7 ± 2.8 and 9.5 ± 2.9 kg) than RLC forwards and backs. Observed differences may reflect selection based on favourable physical attributes, or training adaptations. To reduce this discrepancy, some RLC players should reduce fat mass and increase lean mass, which may be of benefit for the 2015 season and beyond

Sound archaeology: terminology, Palaeolithic cave art and the soundscape

This article is focused on the ways that terminology describing the study of music and sound within archaeology has changed over time, and how this reflects developing methodologies, exploring the expectations and issues raised by the use of differing kinds of language to define and describe such work. It begins with a discussion of music archaeology, addressing the problems of using the term ‘music’ in an archaeological context. It continues with an examination of archaeoacoustics and acoustics, and an emphasis on sound rather than music. This leads on to a study of sound archaeology and soundscapes, pointing out that it is important to consider the complete acoustic ecology of an archaeological site, in order to identify its affordances, those possibilities offered by invariant acoustic properties. Using a case study from northern Spain, the paper suggests that all of these methodological approaches have merit, and that a project benefits from their integration

Conceptual and methodological challenges to measuring political commitment to respond to HIV

Background: Researchers have long recognized the importance of a central government’s political “commitment” in order to mount an effective response to HIV. The concept of political commitment remains ill-defined, however, and little guidance has been given on how to measure this construct and its relationship with HIV-related outcomes. Several countries have experienced declines in HIV infection rates, but conceptual difficulties arise in linking these declines to political commitment as opposed to underlying social and behavioural factors. Methods: This paper first presents a critical review of the literature on existing efforts to conceptualize and measure political commitment to respond to HIV and the linkages between political commitment and HIV-related outcomes. Based on the elements identified in this review, the paper then develops and presents a framework to assist researchers in making choices about how to assess a government's level of political commitment to respond to HIV and how to link political commitment to HIV-related outcomes. Results: The review of existing studies identifies three components of commitment (expressed, institutional and budgetary commitment) as different dimensions along which commitment can be measured. The review also identifies normative and ideological aspects of commitment and a set of variables that mediate and moderate political commitment that need to be accounted for in order to draw valid inferences about the relationship between political commitment and HIV-related outcomes. The framework summarizes a set of steps that researchers can follow in order to assess a government's level of commitment to respond to HIV and suggests ways to apply the framework to country cases. Conclusions: Whereas existing studies have adopted a limited and often ambiguous conception of political commitment, we argue that conceiving of political commitment along a greater number of dimensions will allow researchers to draw a more complete picture of political commitment to respond to HIV that avoids making invalid inferences about the relationship between political commitment and HIV outcomes

Three-Compartment Body Composition in Academy and Senior Rugby League Players.

Purpose: This study compared the body size and three compartment body composition between academy and senior professional rugby league players using dual energy X-ray absorptiometry (DXA). Methods: Academy (age 18.1±1.1 years; n=34) and senior (age 26.2 ±4.6 years; n=63) rugby league players received one total-body DXA scan. Height, body mass and body fat percentage alongside total and regional fat mass, lean mass and bone mineral content (BMC) were compared. Independent t-tests with Cohen’s d effect sizes and multivariate analysis of covariance (MANCOVA), controlling for height and body mass, with partial eta squared (η2) effect sizes, were used to compare total and regional body composition. Results: Senior players were taller (183.2±5.8 vs. 179.2±5.7 cm; p=0.001; d=0.70) and heavier (96.5±9.3 vs. 86.5±9.0 kg; p<0.001; d=1.09) with lower body fat percentage (16.3±3.7 vs. 18.0±3.7 %; p=0.032; d=0.46) than academy players. MANCOVA identified significant overall main effects for total and regional body composition between academy and senior players. Senior players had lower total fat mass (p<0.001, η2=0.15), greater total lean mass (p<0.001, η2=0.14) and greater total BMC (p=0.001, η2=0.12) than academy players. For regional sites, academy players had significantly greater fat mass at the legs (p<0.001; η2=0.29) than senior players. Conclusions: The lower age, height, body mass and BMC of academy players suggest that these players are still developing musculoskeletal characteristics. Gradual increases in lean mass and BMC whilst controlling fat mass is an important consideration for practitioners working with academy rugby league players, especially within the lower body

Overcoming the problem of multicollinearity in sports performance data: A novel application of partial least squares correlation analysis

Objectives Professional sporting organisations invest considerable resources collecting and analysing data in order to better understand the factors that influence performance. Recent advances in non-invasive technologies, such as global positioning systems (GPS), mean that large volumes of data are now readily available to coaches and sport scientists. However analysing such data can be challenging, particularly when sample sizes are small and data sets contain multiple highly correlated variables, as is often the case in a sporting context