958 resultados para Sports physiology


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In sport events like Olympic Games or World Championships competitive athletes keep pushing the boundaries of human performance. Compared to team sports, high achievements in many athletic disciplines depend solely on the individual's performance. Contrasting previous research looking for expertise-related differences in brain anatomy at the group level, we aim to demonstrate changes in individual top athlete's brain, which would be averaged out in a group analysis. We compared structural magnetic resonance images (MRI) of three professional track-and-field athletes to age-, gender- and education-matched control subjects. To determine brain features specific to these top athletes, we tested for significant deviations in structural grey matter density between each of the three top athletes and a carefully matched control sample. While total brain volumes were comparable between athletes and controls, we show regional grey matter differences in striatum and thalamus. The demonstrated brain anatomy patterns remained stable and were detected after 2 years with Olympic Games in between. We also found differences in the fusiform gyrus in two top long jumpers. We interpret our findings in reward-related areas as correlates of top athletes' persistency to reach top-level skill performance over years.

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The animal gut plays a central role in tackling two common ecological challenges, nutrient shortage and food-borne parasites, the former by efficient digestion and nutrient absorption, the latter by acting as an immune organ and a barrier. It remains unknown whether these functions can be independently optimised by evolution, or whether they interfere with each other. We report that Drosophila melanogaster populations adapted during 160 generations of experimental evolution to chronic larval malnutrition became more susceptible to intestinal infection with the opportunistic bacterial pathogen Pseudomonas entomophila. However, they do not show suppressed immune response or higher bacterial loads. Rather, their increased susceptibility to P. entomophila is largely mediated by an elevated predisposition to loss of intestinal barrier integrity upon infection. These results may reflect a trade-off between the efficiency of nutrient extraction from poor food and the protective function of the gut, in particular its tolerance to pathogen-induced damage.

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Concussion, a frequent injury in sports, is rarely evoked and often trivialized in children and teenagers. Knowledge of the diverse symptoms and signs to seek for is essential to an appropriate and secure management. The initial treatment relies on cognitive and physical rest followed by a progressive return to school and subsequently sport activities. The aim of this article is to review an injury whose prognosis is generally favourable, but whose rare complications can prove dramatic.

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In the context of globalized competition among territories, cities, regions and countries have to find new ways to be attractive to companies, investors, tourists and residents. In that perspective, major sports events (such as the Olympic Games or the FIFA World Cup) are often seen as a lever for territorial development. Based on that idea, many sports events hosting strategies have emerged in the 1980s and 1990s. However, the growing competition in the sports events' market and the gigantism of those major events, forced some territories to turn to smaller events. This necessary resize of their strategy raises the question of their capacity to meet the initial objectives, which aim usually at developing the economy and promoting the image of the host destination. This essay sketches out the evolution of a sports events hosting strategy in a city that does not have the resources (either financial, human or in terms of infrastructures) to attract major international sports events. The challenges they have to face and a possible solution based on the event portfolio perspective are discussed through the article.

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The purpose of this paper is to examine the CSR practices and their implementation in the context of French professional sports clubs. In doing so, it analyses the link between the governance of sports clubs and CSR, which is viewed as a component of governance expanded to stakeholders and contributing to the creation of shared value. Drawing on interview data with key stakeholders of four professional sport clubs (football and basketball) and secondary material, the study sheds light on the determinants, the implementation as well as the impact of CSR on the governance of the professional clubs under examination.

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The detection of testosterone abuse in sports is routinely achieved through the 'steroidal module' of the Athlete Biological Passport by GC-MS(/MS) quantification of selected endogenous anabolic androgenic steroids (EAAS) from athletes' urines. To overcome some limitations of the "urinary steroid profile" such as the presence of confounding factors (ethnicity, enzyme polymorphism, bacterial contamination, and ethanol), ultrahigh performance liquid chromatography (UHPLC) measurements of blood concentrations of testosterone, its major metabolites, and precursors could represent an interesting and complementary strategy. In this work, two UHPLC-MS/MS methods were developed for the quantification of testosterone and related compounds in human serum, including major progestogens, corticoids, and estrogens. The validated methods were then used for the analyses of serum samples collected from 19 healthy male volunteers after oral and transdermal testosterone administration. Results from unsupervised multiway analysis allowed variations of target analytes to be assessed simultaneously over a 96-h time period. Except for alteration of concentration values due to the circadian rhythm, which concerns mainly corticosteroids, DHEA, and progesterone, significant variations linked to the oral and transdermal testosterone administration were observed for testosterone, DHT, and androstenedione. As a second step of analysis, the longitudinal monitoring of these biomarkers using intra-individual thresholds showed, in comparison to urine, significant improvements in the detection of testosterone administration, especially for volunteers with del/del genotype for phase II UGT2B17 enzyme, not sensitive to the main urinary marker, T/E ratio. A substantial extension of the detection window after transdermal testosterone administration was also observed in serum matrix. The longitudinal follow-up proposed in this study represents a first example of 'blood steroid profile' in doping control analysis, which can be proposed in the future as a complement to the 'urinary module' for improving steroid abuse detection capabilities.

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The book adopts a unique stakeholder perspective, structured around the groups and individuals who have an interest in and co-create sports events, including organising committees, promoters, sport organisations, spectators, community groups, sponsors, host governments, the media and NGOs. Each chapter addresses a specific stakeholder, defines that stakeholder and its relationships with sports events, describes the managerial requirements for a successful event, assesses current research and directions for future research, and outlines the normative dimensions of stakeholder engagement (such as sustainability and legacy)

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Phospholipid vesicles of less than 1 μm are present in blood in physiological state and their concentration may vary under pathological conditions. Various names such as exosomes (EXS) and microparticles (MPS) have been used to designate these extracellular vesicles (EVS). Although EXs and MPS possibly arise from separate mechanisms, they share numerous similarities representing a challenge for their purification and characterization. These vesicles generally originate from various types of cells such as red blood cells, platelets, leukocytes or endothelial cells but also from tumor cells. They participate in numerous biological processes including hemostasis. It is therefore of major scientific interest to characterize the protein content of these different types of EVS and that of their membranes in order to elucidate the essential functions of these dynamic vesicular compartments. Proteomics has been shown to be a particularly adequate tool in this study field. This review attempts to link proteomic data with physiological roles and functions of blood EVS.

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International sport governing bodies (ISGBs) are built on the foundations of freedom of association and traditionally enjoy a large degree of autonomy in their decision-making. Their autonomy is increasingly confined, however, and their hierarchical self-governance is giving way to a more networked governance, in which different stakeholders exert power in different ways and in different contexts in a complex web of interrelationships. Taking a rationalist perspective on the autonomy of ISGBs, this article demonstrates that ISGBs are deploying strategies to safeguard their waning governing monopoly over international sport. Opting for an inductive approach, the authors present four possible conceptualizations of autonomy as applied to ISGBs, namely political autonomy, legal autonomy, financial autonomy and pyramidal autonomy. For each dimension, they describe the different strategies ISGBs wield in order to safeguard different dimensions of their autonomy. This article uses governance theories to hypothesize that the autonomy of ISGBs can be understood as 'pragmatic autonomy' since ISGBs only cede certain aspects of their autonomy under particular circumstances and when being subject to specific threats. Acting in a rationalist manner, they are able to keep control over governance developments in sport by using indirect and more subtle forms of governance.