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Questions continue to be raised about the validity that is in existence to estimate Db, in professional male footballer players. Phase 1: n = 28 anthropometric variables were used on n = 206 footballers, using regression analyses to determine standard error of estimate and R2. A cut-off correlation coefficient set at r = 0.950 and 90% R2. Phase 2: all variables (z-scores, $$\bar x$$ x ˉ = 0.0, SD = ±1.0) to help reduce heteroscedasticity, β, r, t, significance of t and P-values were calculated. Phase 3: a forced stepwise–backwards regression analysis approach with nine predictors which met the acceptance criteria (r = 0.950, R2 = 90% and β weights) was used to develop a 'best fit' and a 'practical' calibration model. Phase 4: cross-validation of the two newly developed calibration method using LoA. The 'best fit' model SEM (0.115 g ml−1), the highest R2 (6.6%) (P ≤ 0.005), whereas the 'practical' calibration model SEM (0.115 g ml−1), R2 (4.7%) (P ≤ 0.005) with r values = 0.271 and 0.596 and R2 (%) coefficients = 0.3526 for the 'best fit' and 'practical' calibration models, respectively (P = 0.01). The two calibration models supported an ecologically and statistically valid contribution and can provide sound judgements about professional footballers' body composition. [ABSTRACT FROM AUTHOR]

This study examined the independent relationships between cardiorespiratory and muscular fitness with cardiometabolic risk in adolescents. Subjects were 192 adolescents (118 boys), aged 15–17.5 years. The 2 m multi-stage fitness test assessed cardiorespiratory fitness and the counter movement jump assessed muscular fitness. Additional measures included interleukin-6, C-reactive protein, adiponectin, fibrinogen and plasminogen activator inhibitor-1. Regression analysis revealed that cardiorespiratory fitness was negatively related to cardiometabolic risk (β = –0.014,p< 0.001). With additional adjustment for muscular fitness the relationship remained significant (β = –0.015,p< 0.001). Muscular fitness was negatively related to cardiometabolic risk (β = –0.021,p< 0.001) and remained significant after adjustment for cardiorespiratory fitness. Participants in the least-fit quartile for both cardiorespiratory and muscular fitness had significantly poorer cardiometabolic risk scores than those in the other quartiles. Findings revealed that muscular and cardiorespiratory fitness are significantly associated with cardiometabolic risk independently of one another. [ABSTRACT FROM PUBLISHER]

An abstract of the article "A simple statistical method for assessing the reliability of data entered into sport performance analysis systems," by Stephen-Mark Cooper, Mike Hughes, Peter O'Donoghue, and Alan M. Peter is presented.

In recent years the British media have made much of the apparent decline of standards in British sports. In order to interrogate the veracity of media assumptions regarding the standards of conduct in major British sports, a selection of British sports spectators were interviewed in order to examine: (i) their perceptions of the values and norms of sport; (ii) whether they thought that sporting conduct as currently demonstrated by UK sportsmen and women was positive and related to some ideal notion of the 'ethos of sport' and the 'spirit of the game;' (iii) whether they thought that there had been an improvement, a decline or no change in the ethical standards of conduct in those sports; and (iv) views on the impact of new technologies on the values and norms of sport. At least 200 questionnaires were collected from spectators at each of the following major sporting events: (a) the English Nationwide Football League Divisions 2 and 3 play-offs, Cardiff, May 2001; (b) the All England Tennis Championships, Wimbledon, July 2001; (c) the England vs Australia Cricket Test match, Edgbaston Birmingham, July 2001; and (iv) the British Open Golf Championships, Royal Lytham and St Annes, Lancashire, July 2001. Results showed that there were statistically significant differences in what sports spectators thought about British professional sportspersons acting in a fair and sporting way and also that standards of conduct had generally declined over the last 10 years. A general pattern of distribution emerged where the team sports (cricket and football) were less favourably perceived than the individual sports (golf and tennis). [ABSTRACT FROM AUTHOR]

In this paper, we identify appropriate statistical methods for analysing categorical differences in discrete variables or 'performance indicators' resulting from performance analysis. The random mechanisms associated with discrete events do not follow a normal distribution; that is, the normal distribution is a continuous not a discrete probability distribution. We propose appropriate statistical methods based on two key discrete probability distributions, the Poisson and binomial distributions. Two approaches are proposed and compared using examples from notational analysis. The first approach is based on the classic chi-square test of significance (both the goodness-of-fit test and the test of independence). The second approach adopts a more contemporary method based on log-linear and logit models fitted using the statistical software GLIM. Provided relatively simple one-way and two-way comparisons in categorical data are required, both of these approaches result in very similar conclusions. However, as soon as more complex models or higher-order comparisons are required, the approach based on log-linear and logit models is shown to be more effective. Indeed, when investigating those factors and categorical differences associated with binomial or binary response variables, such as the proportion of winners when attempting decisive shots in squash or the proportion of goals scored from all shots in association football, logit models become the only realistic method available. By applying log-linear and logit models to discrete events resulting from notational analysis, greater insight into the underlying mechanisms associated with sport performance can be achieved. [ABSTRACT FROM AUTHOR]

The main aim of this study was to identify significant relationships between selected anthropometric and kinematic variables and ball release speed. Nine collegiate fast-medium bowlers (mean ±s: age 21.0 ± 0.9 years, body mass 77.2 ± 8.1 kg, height 1.83 ± 0.1 m) were filmed and reconstructed three-dimensionally. Ball release speeds were measured by a previously validated Speedchek™ Personal Sports Radar (Tribar Industries, Canada). Relationships between selected anthropometric variablesand ball release speed and between kinematic variables and ball release speed were investigated using Pearson's product-moment correlation coefficients (r). A significant relationship was found between the horizontal velocity during the pre-delivery stride (r = 0.728, P< 0.05) and ball release speed (31.5 ± 1.9 m·s[sup -1]). We believe that the high correlation was due to the bowlers using techniques that allowed them to contribute more of the horizontal velocity created during the run-up to ball release speed. We also found that the angular velocity (40.6 ± 3.4 rad·s[sup -1]) of the right humerus had a low correlation (r = 0.358,P> 0.05) with ball release speed. Although the action of the wrist was not analysed because of an inadequate frame rate, we found high correlations between ball release speed and shoulder-wrist length (661 ± 31 mm;r = 0.626,P< 0.05) and ball release speed and total arm length (860 ± 36 mm;r = 0.583, P < 0.05). We conclude that the variance in release speed within this group may be accounted for by the difference in radial length between the axis of rotation at the glenohumeral joint and the release point. [ABSTRACT FROM AUTHOR]