57 research outputs found

    The importance of measuring body composition in professional football players: A commentary

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    Professional football players are not considered to be excessively fat, but there is continuous pressure made by managers, coaches and physiotherapists to monitor player’s body composition to help reach optimal performance potential. Consequently, it is not uncommon for sport scientists to assume responsibility for monitoring and managing their players’ body composition over the playing season. As body fat is one of the main factors affecting body composition, the knowledge and understanding of whole body density and how it inluences the body could be useful to quantify the effectiveness of a prescribed training programme and/ or optimal performance potential

    Measurement reliability and precision of anthropometric measures for the estimation of whole body density in professional football players

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    Introduction: It is not uncommon to encounter measurement reliability issues, yet when they are required to develop practical calibration models to estimate whole body density the reliability of anthropometric measures is imperative. Materials and Methods: Data was gathered from n=206 male professional footballers ( ±s; age = 24.1±5.4 years, body mass = 78.8±8.4 kg and stretched stature = 180.1±7.0 cm). Reliability of n=28 anthropometric variables (skinfolds, girths, breadths, depths, widths, residual lung volume, air displacement plethysmography and hydrostatic weighing) was investigated by applying Technical Error of Measurement (TEM%) and the Limits of Agreement (LoA) method. Results: TEM% indicated a range of 6.5-1.0% and 3.8-0.6% and the study’s a priori criterion was set at ±3.8% for LoA and were statistically significant (P < 0.001). The contentious measurements of the iliac crest, supraspinale and anterior thigh skinfold, chest and hip girth and biiliocristal breadth indicated z scores values for R2 between 0.006-0.022% and exhibited significant bias (P=< 0.05) and possible heteroscedasticity issues with highest r values of 0.611 and R2 (%) coefficients of 37.3%. Discussion: Test-retest values demonstrated agreement and reliability to be of practical use with this population

    Agreement and validity of existing anthropometric calibration models to estimate whole body density in male professional football players

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    Introduction To date no calibration models exist to estimate whole body density (Db) of professional footballers, as such the development of practical anthropometric calibration models to make sound body composition judgements is imperative. The aim of this study was to investigate the agreement and validity of estimating Db from 15 existing calibration models through comparison to a criterion method of hydrostatic weighing (HW) in male professional footballers. Materials and Methods Data were gathered from a total of n=206 professional football participants (x±s; age=24.1±5.4-years, body mass=78.8±8.4 kg, stature=180.1±7.0 cm, Db 1.075±0.01 g.ml-1). Bland and Altman limits of agreement (LoA) approaches were used to determine bias and random variation derived from the calibration models. Results Bias and random errors for the published calibration models ranged from -0.005 to +0.015 g.ml-1 and 1.012 to 1.090 g.ml-1 respectively. A priori criterion (±3.8% p=<0.05 (g.ml-1)) was set as acceptable limits for the LoA method of which 13 calibration models found that (on average) estimated Db derived from HW was greater than Db derived from the models. Discussion A rank order of LoA identified the best model to use, however, LoA were not narrow enough for measurements to be of practical use and in most instances, selected models are not appropriate for estimating Db in male professional footballers

    Agreement and validity of existing anthropometric calibration models to estimate whole body density in male professional football players

    Get PDF
    Introduction To date no calibration models exist to estimate whole body density (Db) of professional footballers, as such the development of practical anthropometric calibration models to make sound body composition judgements is imperative. The aim of this study was to investigate the agreement and validity of estimating Db from 15 existing calibration models through comparison to a criterion method of hydrostatic weighing (HW) in male professional footballers. Materials and Methods Data were gathered from a total of n=206 professional football participants (x±s; age=24.1±5.4-years, body mass=78.8±8.4 kg, stature=180.1±7.0 cm, Db 1.075±0.01 g.ml-1). Bland and Altman limits of agreement (LoA) approaches were used to determine bias and random variation derived from the calibration models. Results Bias and random errors for the published calibration models ranged from -0.005 to +0.015 g.ml-1 and 1.012 to 1.090 g.ml-1 respectively. A priori criterion (±3.8% p=<0.05 (g.ml-1)) was set as acceptable limits for the LoA method of which 13 calibration models found that (on average) estimated Db derived from HW was greater than Db derived from the models. Discussion A rank order of LoA identified the best model to use, however, LoA were not narrow enough for measurements to be of practical use and in most instances, selected models are not appropriate for estimating Db in male professional footballers

    ExoMol line lists - XLIV. IR and UV line list for silicon monoxide (SiO)

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    A new silicon monoxide (28Si16O) line list covering infrared, visible and ultraviolet regions called SiOUVenIR is presented. This line list extends the infrared EBJT ExoMol line list by including vibronic transitions to the A 1Π and E 1Σ+ electronic states. Strong perturbations to the A 1Π band system are accurately modelled through the treatment of 6 dark electronic states: C 1Σ−, D 1Δ, a 3Σ+, b 3Π, e 3Σ− and d 3Δ. Along with the X 1Σ+ ground state, these 9 electronic states were used to build a comprehensive spectroscopic model of SiO using a combination of empirical and ab initio curves, including the potential energy (PE), spin-orbit (SO), electronic angular momentum (EAM) and (transition) dipole moment curves. The ab initio PE and coupling curves, computed at the multireference configuration interaction (MRCI) level of theory, were refined by fitting their analytical representations to 2617 experimentally derived SiO energy levels determined from 97 vibronic bands belonging to the X–X, E–X and A–X electronic systems through the MARVEL procedure. 112 observed forbidden transitions from the C–X, D–X, e–X, and d–X bands were assigned using our predictions, and these could be fed back into the MARVEL procedure. The SiOUVenIR line list was computed using published ab initio transition dipole moments for the E–X and A–X bands; the line list is suitable for temperatures up to 10 000 K and for wavelengths longer than 140 nm. SiOUVenIR is available from www.exomol.com and the CDS database

    ExoMol line lists - XLIV. IR and UV line list for silicon monoxide (SiO)

    Get PDF
    A new silicon monoxide (28Si16O) line list covering infrared, visible and ultraviolet regions called SiOUVenIR is presented. This line list extends the infrared EBJT ExoMol line list by including vibronic transitions to the A 1Π and E 1Σ+ electronic states. Strong perturbations to the A 1Π band system are accurately modelled through the treatment of 6 dark electronic states: C 1Σ−, D 1Δ, a 3Σ+, b 3Π, e 3Σ− and d 3Δ. Along with the X 1Σ+ ground state, these 9 electronic states were used to build a comprehensive spectroscopic model of SiO using a combination of empirical and ab initio curves, including the potential energy (PE), spin-orbit (SO), electronic angular momentum (EAM) and (transition) dipole moment curves. The ab initio PE and coupling curves, computed at the multireference configuration interaction (MRCI) level of theory, were refined by fitting their analytical representations to 2617 experimentally derived SiO energy levels determined from 97 vibronic bands belonging to the X–X, E–X and A–X electronic systems through the MARVEL procedure. 112 observed forbidden transitions from the C–X, D–X, e–X, and d–X bands were assigned using our predictions, and these could be fed back into the MARVEL procedure. The SiOUVenIR line list was computed using published ab initio transition dipole moments for the E–X and A–X bands; the line list is suitable for temperatures up to 10 000 K and for wavelengths longer than 140 nm. SiOUVenIR is available from www.exomol.com and the CDS database

    Aristophanes and De Ste. Croix: The value of old comedy as evidence for Athenian popular culture

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    De Ste. Croix famously argued that Aristophanes had a conservative political outlook and attempted to use his comedies to win over lower-class audiences to this minority point of view. The ongoing influence of his interpretation has meant that old comedy has been largely ignored in the historiography of Athenian popular culture. This article extends earlier critiques of de Ste. Croix by systematically comparing how Aristophanes and the indisputably popular genre of fourth-century oratory represented the social classes of the Athenians and political leaders. The striking parallels between the two suggest that Aristophanes, far from advocating a minority position, exploited the rich and, at times, contradictory views of lower-class citizens for comic and ultimately competitive ends. As a consequence his plays are valuable evidence for Athenian popular culture and help to correct the markedly fourth-century bias in the writing of Athenian cultural history
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