The workout responses of salivary-free testosterone and cortisol concentrations and their association with the subsequent competition outcomes in professional rugby league

This study assessed the responses of salivary-free testosterone (T) and cortisol (C) concentrations across selected training workouts and their association with the subsequent competition outcomes in professional rugby league. Thirteen rugby league players were assessed for salivary-free T and C concentrations across 5 training workouts performed 3-4 days before a competitive game. The game outcomes included wins and losses and game-ranked performance (1-5) based on the number of points scored, the points differential, and a coach rating. Data were pooled across the winning (n = 3) and losing (n = 2) outcomes. Pooled free T concentrations (absolute and relative changes) were significantly (p < 0.01) elevated across those workouts that preceded winning games, but not the losses, and the relative (percent) T changes were significantly (p < 0.05) higher before winning (30.9%) than before losing (3.4%). Both outcomes were associated with workout decreases in pooled free C concentrations and the relative C changes were not significantly different between wins (222.9%) and losses (225.6%). In conclusion, the free T responses to selected training workouts showed some association with subsequent winning (being elevated) and losing (no change) during a limited number of competitive games in professional rugby league. Speculatively, the free T responses to a midweek workout might provide an early sign of team readiness to compete or to recovery state, thereby providing a novel format for implementing training or management strategies to improve the competition outcomes

Influence of Nanoparticles on the Coupling Between Optical Dipoles in Epoxy-Silica Nanocomposites During Network Formation

High-performance refractometry and infrared spectroscopy are combined in order to elucidate the gelation process and the glass transition during the network formation of epoxies and epoxy-based nanocomposites. Whereas infrared spectroscopy yields the chemical conversion due to the opening of oxirane rings during the covalent network formation, high-performance refractometry is extremely sensitive to the accompanying changes of the arrangement of the molecular network. In accordance with the Lorentz-Lorenz relationship, the evolution of the refractive index seems to reflect that of the mass density during polymerization of the epoxy-based systems within the limits of a few percent. The slight deviations from the Lorentz-Lorenz relationship, which occur during the gelation of the epoxy-based systems, are attributed to long-ranged dipole-dipole interactions, which respond at optical frequencies. This point of view is supported by the fact that chemically inert silica nanoparticles embedded in the pure epoxy matrix as disturbances for these dipole-dipole interactions are able to diminish or even to suppress totally this excess contribution of the refractive index

Predicting self-reported illness for professional team-sport athletes

Purpose: To identify contributing factors to the incidence of illness for professional team-sport athletes, using training load (TL), self-reported illness, and well-being data. Methods: Thirty-two professional rugby league players (26.0 ± 4.8 y, 99.1 ± 9.6 kg, 1.84 ± 0.06 m) were recruited from the same club. Players participated in prescribed training and responded to a series of questionnaires to determine the presence of self-reported illness and markers of well-being. Internal TL was determined using the session rating of perceived exertion. These data were collected over 29 wk, across the preparatory and competition macrocycles. Results: The predictive models developed recognized increases in internal TL (strain values of > 2282 AU, weekly TL > 2786 AU, and monotony > 0.78 AU) to best predict when athletes are at increased risk of self-reported illness. In addition, a reduction in overall well-being ( < 7.25 AU) in the presence of increased internal TL, as previously stated, was highlighted as a contributor to self-reported-illness occurrence. Conclusions: These results indicate that self-report data can be successfully used to provide a novel understanding of the interactions between competition-associated stressors experienced by professional team-sport athletes and their susceptibility to illness. This may help coaching staff more effectively monitor players during the season and potentially implement preventive measures to reduce the likelihood of illnesses occurring

The seven step approach to the application of sport science in English professional rugby league: practical considerations in strength and conditioning

This article examines the training and competition loads performed with a full-time professional rugby league team during a Super League season (pre- and in-season). While a logical and evidence-based approach was taken, involving initial planning, delivery, monitoring and evaluation, the idiosyncratic aspects of such a professional environment required a high degree of tacit knowledge and adaptability. The current article will therefore describe the context, outline the broad process and approach, provide some detailed case examples of support work undertaken with associated data, and identify the methods for evaluation. The use of four case studies (i.e., injury audit; hydration in a training week; alternative training strategy; and monitoring) helped review and inform strength and conditioning practice within a professional rugby league club environment