Le football est en constant développement, la détection, le développement de jeunes talents sont devenus des priorités stratégiques et économiques pour les clubs et les fédérations. Les structures proposant un entraînement de football pour l’enfant se développent et sont de plus en plus nombreuses : les sections sport études, les centres de préformation, les centres de formation et les académies permettent aux jeunes de poursuivre leur passion et/ou leur rêve de haut niveau. Néanmoins, il est important de se rappeler que le développement du jeune ne peut être assimilé à celui de l’adulte et du joueur professionnel : « L’enfant est un petit d’homme et non pas un petit homme » (Jean Jacques Rousseau). Le contenu de l’entraînement se doit de respecter des principes adaptés à leur âge et à leur niveau. Mais quels contenus ? La présente thèse a pour objectif principal de déterminer l’impact de six ans d’entraînement physique dans la stratégie technico-tactique sur des jeunes joueurs de football en formation pour accéder au haut niveau. D’apporter une revue de littérature complète sur l’ensemble des indicateurs de la performance et de la vitesse du joueur de football en formation, ainsi que sur les différents facteurs d’influence. Dans un second temps, l’objectif de cette thèse consiste à étudier l’influence d’un programme d’entraînement de deux types de travail de vitesse et d’analyser leur impact sur la vitesse de démarrage et les premiers mètres (0 à 10 mètres) appliquée à des joueurs de football marocains âgés de 12-17 ans (ETUDE 1). Ensuite nous avons analysé l’impact des différentes étapes évolutives des qualités physiques et de ces performances sur les compétences techniques et tactiques dans la performance du football (ETUDE 2). L’ETUDE 3 a permis d’étudier sur la façon dont la performance s'améliore chez les jeunes footballeurs d'élite marocains pendant six saisons de football (12 à 17 ans) liées à l'évolution des caractéristiques anthropométriques et des qualités physiques. Les résultats de cette troisième étude ont permis d'établir, pour la première fois en Afrique : le profil du jeune joueur de football nord-africain de 17 ans (U18). Pour finir, en complément, une étude clinique (ETUDE 4), durant six saisons de la préformation à la formation sur de jeunes apprentis footballeurs (U12 à U17), propose un constat, un bilan et des perspectives du projet de formation footballistique. Ainsi quels contenus les jeunes footballeurs de l’Académie ont réalisés durant les six de formation, en préformation (U12-U15) et formation (U16-U17) et quels sont les perspectives d’implication pratique pour le footballeur nord-africain ? En conclusion, la connaissance des besoins des joueurs de football lors des périodes de formation (U12-U18 ans) est cruciale pour les formateurs et entraîneurs afin qu’ils puissent adapter les stratégies adéquates dans le but de former les futures joueur élites de demain et pour maintenir leur équipe la plus performante. / Football is in constant development, detection, the development of young talents have become strategic and economic priorities for clubs and federations. The structures offering afootball training for the child are developing and are becoming more numerous: sports studiessections, pre-training centers, training centers and academies allow young people to pursue their passion and / or their dream high level. Nevertheless, it is important to remember that the development of the young can not be assimilated to that of the adult and the professional player: "The child is a little man and not a little man" (Jean Jacques Rousseau). The content of the training must respect principles adapted to their age and level. But what content ? The main aim of this thesis is to determine the impact of six years of physical training in the technical-tactical strategy on young football players in training to reach the highest level. Toprovide a complete literature review on all indicators of the performance and speed of the football player in training, as well as on the various influencing factors. In a second step, the objective of this thesis is to study the influence of a training program of two types of work of speed and to analyze their impact on the speed of starting and the first meters (0 to 10 meters) applied to Moroccan football players aged 12-17 (STUDY 1). Then we analyzed the impact of the different evolutionary stages of physical qualities and performances on technical and tactical skills in the performance of football (STUDY 2). STUDY 3 examined how performance improves among young Moroccan elite footballers in six football seasons (12-17 years) related to changes in anthropometric characteristics and physical qualities. The results of this third study have established, for the first time in Africa: the profile of the young 17-year-old North African football player (U18). Finally, in addition, a clinical study (STUDY 4), during six seasons of training preformation on young apprentice footballers (U12 to U17), offers a report, a review and prospects of the football training project. So, what content did the young footballers of the Academy make during the six training, pre-training (U12-U15) and training (U16-U17) and what are the prospects of practical involvement for the North African footballer ? In conclusion, the knowledge of the needs of football players during training periods (U12-U18 years) is crucial for trainers and coaches so that they can adapt the appropriate strategies in order to train future elite players of tomorrow and to keep their team the most efficient.

In recent years our understanding of the physical demands of soccer has improved. We know that the intensity at which the game is played has increased and that the fixture schedules for professional teams can often be very congested. These factors are likely to have increased the importance placed on the physical condition of players. Therefore, the process of monitoring the fitness levels of players is likely to be an important task within clubs. Any fitness assessments that are employed need to be sensitive enough to detect changes that may result from different training stimuli. A further critical consideration for clubs is what are the best practices to implement in order to maximise recover between matches? The two areas that are central to successful recovery of performance are the restoration of muscle and liver glycogen stores and the rapid reduction of muscle soreness. We have a good understanding of the importance of carbohydrate feeding in the immediate hours following the completion of exercise, furthermore that high levels of carbohydrate consumed during short recovery periods can improve subsequent endurance running capacity in both continuous and intermittent exercise. However, there is dearth of literature investigating the effects that different types (glycemic index) of carbohydrates have on subsequent performance of high intensity intermittent exercise. Furthermore, we know that the movement patterns experienced in soccer commonly induce symptoms of muscle damage. Despite this there is little research based information on modalities that reduce these potentially detrimental side-effects (Bamett, 2006). For these reasons the series of investigations that have been conducted in this thesis were designed with the intent to examine areas that are critical to the preparation and recovery of soccer players. The first of five experimental chapters collated information on the use of fitness testing within English professional football. It was concluded that the practise of fitness testing players is extremely commonplace and that field-based testing protocols were far more popular an assessment method. The second experimental chapter went on to demonstrate that the most commonly used fitness test within professional football (MSFT) was sensitive enough to detect performance changes that occur as a result of training. A further finding within the context of the question was that it is possible for female players to significantly improve aerobic capabilities with additional high intensity aerobic training. The third experimental chapter investigated the effect different glycemic index high CHO diets could have on recovery of performance following 90 min of intermittent soccer type exercise. This study concluded that consuming either predominately high or low GI CHO mixed meals in the 24h recovery period between bouts of high intensity prolonged intermittent exercise had no difference on measures of performance. The final two experimental chapters went on to investigate the effects of cold water immersion on indices of muscle damage following intermittent exercise. Results from these investigations suggest that submerging individuals in 10°C water immediately following high intensity intermittent exercise reduces some but not all indices of muscle damage. In summary, fitness assessments of players are commonly made within professional football clubs. The most common test used was the MSFT and this appears to be sensitive to changes that result as a consequence of training. During recovery from high intensity intermittent exercise the importance of carbohydrates is apparent although the type of carbohydrate appears to be less important, furthermore, cold-water immersion may be effective in reducing some but not all indices of muscle damage.

La thèse est consacrée à la sociologie de la formation au métier de footballeur. Il s'agit de comprendre comment on devient, ou non, joueur de football professionnel, aussi bien du point de vue de celui qui vit la formation (le joueur) que de celui qui la fait (le formateur). Pour cela, nous avons mené une série d'entretiens (quatre-vingt dix) et d'observations (cinquante séances d'entraînement et deux semaines d'immersion continue) dans les trois clubs professionnels de la région Nord / Pas de Calais que sont le Racing Club de Lens, le Lille Olympique Sporting Club et le Valenciennes Football Club ainsi qu'au centre fédéral de préformation de Liévin. La démarche de comparaison entre les différentes instances de formation que nous avons adoptée permet d'emblée de questionner l'unicité supposée du système de formation "à la française". En parallèle de cette comparaison des lieux de formation, le recours au concept de carrière permet, en observant l'entrée, le déroulement et la sortie de la formation, de mettre en évidence l'absence de linéarité dans les trajectoires qui amènent au professionnalisme.C'est au cours de plusieurs étapes rythmées par moments clés, en côtoyant divers groupes et segments professionnels que se structure progressivement une identité professionnelle de joueur de football de haut niveau. Mais si les lauréats sont à l'évidence devenus des professionnels d'un système de formation hyper sélectif et incertain, sont-ils, pour autant préparés à affronter le marché du travail des footballeurs ? Lorsque l'on sait que plus de la moitié des premiers contrats professionnels ne seront pas renouvelés, rien n'est moins sûr. / The thesis focuses on how to get to the various stages to the work of professional footballer, seen from sociological aspects. We want to understand how it is possible to become – or not – a professional football player both from the perspective of the one who lives training (the player) and the one who makes it (the trainer). In order to do this, we conducted a series of interviews (ninety) and observations (fifty training sessions and two weeks of continuous immersion) in the three professional clubs in the region Nord / Pas de Calais that are the Racing Club of Lens, the Lille Olympique Sporting Club and the Valenciennes Football Club and the federal preformation center of Lievin. Comparing these different places of the formation, allows us immediately to question the supposed unity of the French football model of education. Besides this first comparison, using the concept of career allows us, by observing the beginning, the process and the close of the education, to show that there is no linearity in the trajectories that lead to the work of professional football player. It is during several stages defined by key moments and by meeting different professional groups and segments that the football player’s professional identity is progressively structured. However, we can wonder if young people who manage to survive to a such uncertain and selective model of formation are really prepared to evolve in the professional football market. When we know that half of the first professional football contracts are not prolonged, we can’t positively answer to this.

Psychosocial factors are the interrelated psychological, social and/or behavioural considerations that can influence talent development in football (Holt & Dunn, 2004). Despite this, the significant growth of female football worldwide, and the psychosocial challenges faced by female athletes during adolescence, scant scholarly attention has been afforded to the role of psychosocial factors in the development of talented female football players. Therefore the main aim of this thesis was to understand psychosocial factors associated with talent development in UK female football players. Study one systematically reviewed the literature on psychosocial factors associated with talent development in soccer. Following an extensive literature searching, selecting and appraisal process, three overarching themes of psychological, social and behavioural factors associated with talent development in soccer - underpinned by a total of 33 subthemes were created. The appraised literature has a moderate-to-high risk of reporting bias; had a significant bias towards adolescent, Caucasian, male, able-bodied, and European soccer players; and extant literature has demonstrated bias towards quantitative approaches and retrospective data collection methods. Consequently, study two began to address these reported biases by longitudinally and prospectively investigating the developmental experiences of English elite female youth soccer players. Through interviews, fieldwork and the use of composite sequence analysis, study two forwarded the importance of psychosocial considerations including the interaction between players and key social agents (soccer fathers, soccer brothers, soccer peers and non- soccer peers), elements of self-regulation and volitional behaviours, and the subsequent developmental benefits for their soccer careers. However, this study did not address the experiences of those who were unsuccessful in their attempts to achieve an elite female soccer career, nor did it collect primary data from other key social agents. Building on the critique of study two, study three sought to adopt an underutilised approach of negative case analysis by examining the experiences of players who had been unsuccessful in their attempts to forge a career in female soccer. Based on interviews former female players, their best friends, coaches and teachers, a grounded theory of talent and career development in UK female youth soccer players was produced. The theory posited that interactions with multiple social agents can affect the quality of talent development and learning environment that a player experiences, which can lead to adaptive player level benefits and changes (e.g., basic psychological need satisfaction; development of pertinent intra-individual constructs; optimal match preparation and training behaviours) and create a greater chance of career success. Study three also forwarded important culturally significant considerations for practitioners working with UK female soccer players, such as an understanding of dual career demands and the impact of role strain on female players. However, study three did not test any of the theoretical predictions offered by the grounded theory. Owing to the need to test predictions of grounded theories to assess their predictive validity, study four sought to test key predictions using a representative sample of English talented and elite adolescent female soccer players (N=137). As a result of the limited structural stability of the Basic Needs Satisfaction in Sport Scale and the Talent Development Environment Questionnaire (as demonstrated by significant cross loading of items, high bivariate correlations between subscales, and one example of an inadequate Cronbach s alpha), data was parcelled and the revised path hypothesis: perceptions of talent development environment > basic psychological needs satisfaction > career aspirations and beliefs > career intentions was produced. Path analysis supported the hypothesis. Supporting findings of studies two and three, regression analysis demonstrated that playing level positively predicted career beliefs, aspirations and intentions; whereas age negatively predicted these variables. Finally, TDEQ results indicated a perception that UK female soccer players that they can be written off before having the opportunity to fulfil their potential. Overall, this thesis has provided original and unique contributions to the sport psychology literature by enlightening the body of research to the developmental experiences of English female youth soccer players. It provides a developmental understanding scarcely evident in existing talent development literature. The interactional roles of multiple social agents have been elucidated and linked to psychosocial development, behavioural outcomes and talent and career progression within talented female players. The thesis has extended previous approaches to talent development in soccer by testing the predictions of the grounded theory. Initial evidence suggests that the proffered grounded theory is robust; however further research utilising structurally sound and ecologically valid measures would serve to further validate these claims.

During the 9th lunar month of each year around 1 billion Muslims adhere to the religious 4- week festival of Ramadan, which is considered as a time for empathy for those less fortunate, a time for restraint, and goodwill. The main focus of the religious intervention of Ramadan is the intermittent fast whereby, each day between dawn and sunset nutritional abstinence is practiced. Empirical evidence from experienced soccer coaches in Qatar has indicated that the 4-week intermittent fast during Ramadan impedes the quality and quantity of training, as well as match play. However, there has been lack of attention directed to the consequences associated with Ramadan and football (soccer) players. Greater understanding of the consequences of Islamic soccer players adhering to lifestyle changes and intermittent fasting would facilitate soccer coaches in a systematic approach to addressing potential negative performance effects associated with Ramadan in future soccer-seasons. In order to address the research problem, a soccer-specific battery of tests was required; as there is no established gold standard battery of soccer-specific field tests preliminary technical and methodological studies were required. In Study-1 a soccer-specific anaerobic capacity field test (Liverpool Anaerobic Speed Test or LAST) was piloted for validity, reliability, and practicality since, the choice for suitable soccer-specific anaerobic capacity tests were inadequate. It was found that two familiarisation sessions are necessary to reduce systematic bias markedly and habituate players with procedures of the LAST. The total measurement error (ratio of Limits of Agreement) of the LAST was 2.5% (± 18 m), and peak blood lactate values produced were 17.6 mmol.l⁻¹, which were greater than the 14.7 mmol.l⁻¹ criteria set for maximal anaerobic effort before the pilot study. The test set-up and administration proved to be practical, facilitating large numbers of subjects to be evaluated relatively quickly ( < 20 min). Therefore, the LAST was included in the soccer-specific battery of field tests, which then provided a comprehensive analysis of the separate components soccer performance. The available facility to conduct this investigation was the soccer-field at Al-Ahli Sports Club Doha, Qatar and therefore, further methodological investigations were necessary; temperatures within Qatar can vary during different times of the season, and at times are quite severe with respect to heat and humidity. The purpose of Study-2 was to examine how robust the discrete soccer-specific field tests were which, would be used during the intervention of Ramadan, using a repeated measures counter-balanced design of indoor and outdoor conditions. It was found that during the Yo-Yo Intermittent Recovery Test (YYIRT) (Krustrup et al., 2003) outdoor assessment maximal performance was reduced by 19% in contrast to the YYIRT conducted indoors, despite the subjects attaining similar maximal heart rates. Consequently, the YYIRT to volitional exhaustion was excluded from the battery of tests to be used during the intervention of Ramadan; all other soccer-specific field tests were found to be robust for use in the heat. The aim of Study-3 was a qualitative investigation to observe current soccer-practice and related factors surrounding training; this brief included bedtime, wake-up time, sleep duration, environmental conditions, pre-training dehydration, body fluids lost during training, body-core temperature, and relative training intensity. During Ramadan it was found that bedtime and wake-up time were significantly delayed and sleep duration lengthened compared to normal. Post-Ramadan was found to be akin to eastward time travel with advancement in bedtime, wake-up and return to normal sleep duration. Dehydration was significantly greater pre-training during Ramadan in comparison to non- Ramadan training weeks, and body fluid loss during training in both Ramadan and non- Ramadan periods was considerable. Relative training workload was also quantified during this time and highlighted important practical problems.

The physical demands of soccer players competing in the English Premier League have significantly increased in recent years (Barnes et al. 2014; Bush et al. 2015). Elite soccer players are required to compete on a weekly and often bi-weekly basis during a 9-month competitive season. During periods of fixture congestion, players may participate in three matches within a 7-day period. Previous researchers have reported that some components of performance and physiological measures may still be below a pre-match baseline 72 hours following match-play (Mohr et al., 2003; Andersson et al., 2008; Ispirlidis et al., 2008; Fatouros et al., 2010). Nevertheless, data are sparse for the quantification of player fatigue status during competitive periods. Therefore, the primary aim of this thesis is to evaluate potential indicators of fatigue which may be easily measured and utilised in elite soccer. The aim of the first study (Chapter 4) was to quantify the test-retest reliability of a range of potential fatigue variables in elite soccer players. During the pre-season period, resting perceived ratings of wellness (fatigue, muscle soreness, sleep quality and stress), counter-movement jump height (CMJ), sub-maximal heart rate (HRex), post-exercise heart rate recovery (HRRbpm and HRR%), heart rate variability (rMSSD and LnrMSSD) and salivary immunoglobulin-A (S-IgA) were measured during the morning on two consecutive non-training days in thirty-five English Premiership players. Mean values of perceived ratings of wellness (7-13 %CV), CMJ (4 %CV) HRex (3 %CV) and HRR% (10 %CV) were not substantially or statistically significantly different between days. HRV measures’ rMSSD (28 %CV) and Ln rMSSD (10 %CV), perceived ratings of sleep (CV 13%CV) and S-IgA (63 %CV) were statistically significantly different between days. All morning-measured fatigue variables with the exception of S-IgA were reliable enough to allow feasible sample sizes in future pre/post studies. These data indicate that the use of perceived ratings of wellness, CMJ, HRR%, and, to a certain extent, HRV (Ln rMSSD) are reliable enough to monitor the fatigue status of a sample of elite soccer players. The aim of the second study (Chapter 5) was to quantify the relationship between daily training load and a range of potential measures of fatigue in elite soccer players during an in-season competitive phase (17-days). Total high-intensity running (THIR) distance, perceived ratings of wellness (fatigue, muscle soreness, sleep quality), CMJ, HRex, HRR% and heart rate variability (Ln rMSSD) were analysed during an in-season competitive period (17 days). Within-subject fluctuations in fatigue (r=-0.51; large; P<0.001), Ln rMSSD (r=-0.24; small; P=0.04), and CMJ (r=0.23; small; P=0.04) were significantly correlated with fluctuations in THIR distance over the study period. Correlations between variability in perceived muscle soreness and sleep quality and HRR% and THIR distance were negligible and not statistically significant. Perceived ratings of fatigue and heart rate variability were sensitive to daily fluctuations in THIR distance in a sample of elite soccer players. Therefore, these specific markers show particular promise as simple, non-invasive assessments of fatigue status in elite soccer players during a short in-season competitive phase. The aim of the third study (Chapter 6) was to determine whether the sensitivity of a range of potential fatigue measures studied in Chapter 5 would be improved compared with the training load accumulated over the previous two, three or four days during a short in-season competitive period (17-days). Fluctuations in fatigue (r=-0.28-0.51; “small” to “large”; p<0.05) were correlated with fluctuations in THIR distance accumulation (1-4-day). Changes in HRex (r=0.28; small; p= 0.02) was correlated with changes in 4-day THIR distance accumulation. Fluctuations in Ln rMSSD (r=-0.24; small; P=0.04), and CMJ (r=0.23; small; P=0.04) were only sensitive to changes in THIR distance for the previous day (Chapter 5). Correlations between variability in muscle soreness, sleep quality and HRR% and THIR distance were negligible and not statistically significant for all accumulation training loads. Perceived ratings of fatigue were sensitive to daily fluctuations in acute THIR distance accumulation although sensitivity attenuated over time. Therefore, the present findings indicate that the sensitivity of morning-measured fatigue measures to changes in training load is not improved when compared with training loads beyond the previous days training. The fourth and final aim of the thesis was to quantify the mean daily changes in training load and parallel changes in measures of fatigue across typical in-season training weeks in elite soccer players. The training load of 29 elite soccer players was measured using the ratings of perceived exertion approach. Perceived ratings of wellness (fatigue, sleep quality and muscle soreness), sub-maximal heart rate (HRex), post-exercise heart rate recovery (HRR) and variability (HRV) were also recorded across training weeks in the in-season competitive period. Morning-measured perceived ratings of fatigue, sleep quality and muscle soreness tracked the changes in RPE-TL, being 35-40% worse on post-match day vs pre-match day (P<0.001). Perceived fatigue, sleep quality and muscle soreness improved by 17-26% from post-match day to three days post-match with further smaller (7-14%) improvements occurring between four days post-match and pre-match day (P<0.01). There were no substantial or statistically significant changes in HRex, HRR% and HRV over the weekly cycle (P>0.05). Morning-measured perceived ratings of fatigue, sleep quality and muscle soreness are clearly more sensitive than HR-derived indices to the daily fluctuations in session load experienced by elite soccer players within a standard in-season week. The results of this thesis have shown that simple, ratings of perceived wellness are reliable and sensitive to short training and competition phases and thus may be a suitable strategy for practitioners to use in the attempt to establish fatigue status in elite soccer players. In particular, this thesis has demonstrated that the greatest sensitivity was observed on a daily basis and during typical training weeks and not during short term load accumulation. . Future work is required to quantify whether perceived ratings of wellness and vagal-related heart rate responses are sensitive to changes in training and match load across an entire competitive season in elite soccer players.

En 2013, dans le parc Gezi d’Istanbul, plus d’un million de personnes ont spontanément déclenché le plus grand mouvement protestataire que la Turquie a connu. Les supporters des trois clubs de football les plus populaires d’Istanbul y ont joué un rôle inédit tant par la forme de leur engagement que par leur mode d’action. Le terrain d’expression de cette contestation était essentiellement constitué par les réseaux sociaux en ligne. La thèse propose de comprendre les raisons de l’implication des supporters et interroge la forme politique de cette mobilisation. Au-delà du football, cet engagement est étroitement dépendant d’un ensemble de conditions historiques et sociales, et de représentations liées à une « doxa républicaine ». L’analyse cyber-ethnographique sur Twitter (qui englobe les messages des supporters) nous a permis de repérer les traces de l’identité urbaine, laïque et « moderne » de ces participants de Gezi, leur rapport au politique et leur adhésion aux valeurs républicaines. / In 2013, at Gezi Park of Istanbul, over a million people spontaneously started the largest protest movement in the history of Turkey. The fans of Istanbul’s three popular football clubs had an unprecedented engagement in these protests. Online social networks were one of the major channels where dissident expressions took place. This thesis aims to understand supporters’ reasons to participate in these protests and the political forms of their mobilization. Beyond football, this engagement is closely associated with a bundle of historical and social conditions and representations, linked with the “republican doxa.” A cyber-ethnography on Twitter that covers football supporters’ messages helps us trace the urban, secular and “modern” identity of these participants of Gezi, their relationship with politics and their allegiance to republican values.

Le rôle des entraîneurs pendant le match au sein du football de jeunes de haut niveau fait débat. En effet, au sein de la littérature scientifique, le sens, les procédures et les processus psychologiques sous-jacents, ainsi que l’efficacité des communications des entraîneurs en situation de match ne sont pas clairement analysés dans toute leur richesse. Notre travail questionne l’intersubjectivité au sein des communications entraîneurs joueurs pendant les matchs. Nous avons dégagé les savoirs d’action mis en œuvre par les entraîneurs pour communiquer et transformer la pratique des joueurs. Nous avons étudié deux types de phases de jeu à savoir, les phases de jeu en mouvement de transition et les phases arrêtées, à travers une approche multiméthodes (observations et entretiens) lors d’études de cas. Notre étude est centrée sur une méthode de triangulation de données qui met en avant le vécu subjectif des acteurs. Les résultats montrent que plusieurs niveaux de contexte structurent la subjectivité des acteurs et le processus d’intersubjectivité lors des communications entraîneurs joueurs. Dans ces deux types de phases de jeu, des styles de communications se sont dégagés et nous avons pu déterminer des indicateurs pertinents relevés par les entraîneurs à propos de l’intersubjectivité, ainsi que des récurrences de fonctionnement. Nous avons mis en exergue les processus psychologiques mis en œuvre par les joueurs pour mieux comprendre comment ils perçoivent les consignes et leur sens. Nos résultats catégorisent trois temporalités de construction de l’intersubjectivité au regard des communications entraîneurs joueurs en situation de match de football. / The role of coaches during top youth league football games is an issue which is discussed.Indeed, through the scientific literature that we have examined, the sense, the procedures and the underlying psychological processes, as well as the efficiency of coaches ' communications during a game has not been clearly analyzed in all their wealth.Our work questions intersubjectivity within the communications between players and coaches during high-level youth games. We cleared the implemented knowledges of action by the coahes to communicate and improve the players' practice. We have studied two types of game phases, namely the phases when players perform transition moves, and phases when they are not in movement, through an approach multimethods (observations and interviews) during case studies. Our study is centered on data triangulation that highlights the subjective perception of the actors. The results show that several levels of context structure the subjectivity of the actors and intersubjectivity process during communicative exchanges between coaches and players. In these two types of game phases, distinctive communication styles have emerged and we were able to identify relevant indicators reported by coaches regarding intersubjectivity, also we determined réccurences of functioning. We highlighted the players' psychological processes so as to better understand how they perceive instructions and how these make sense to them. Our results categorize three temporalities of construction of intersubjectivity in relation to communications in a football game situation between coaches and players.

La fiscalité des clubs et des sportifs professionnels. Quelles que soient les disciplines qu'elles promeuvent, les associations amateurs sont garantes des valeurs véhiculées par le sport. Elles sont à l'origine de toutes créations de sociétés sportives. L'aléa sportif peut conduire un club à reprendre la forme associative suite à des événements sportifs ou financiers (relégation sportive suite à de mauvais résultats, contrôle financier de la DNCG...). L'influence de la fiscalité des clubs et des sportifs professionnels joue un rôle prépondérant dans la compétitivité sportive des clubs français avec leurs voisins européens. En effet, les clubs prennent en charge le salaire de leurs joueurs et leur proposent un salaire net d'impôt. Depuis l'arrêt Bosman rendu en 1995, l'activité footballistique est une activité « ouverte » soumise aux règles européennes de liberté de circulation. Toutefois, une régulation doit être recherchée afin de préserver la spécificité du modèle sportif. Des solutions sont préconisées par les organisateurs de compétitions telles que la FIFA ou l'UEFA. Les sociétés sportives doivent coexister avec les plus grands clubs sportifs européens mais elles doivent aussi maintenir un lien de solidarité financier et sportif avec les associations sportives. Outre les différentes catégories d'impositions auquel le sportif est assujetti, nous aborderons la prise en compte par le législateur des problématiques de fin de carrière du professionnel. Malgré les dispositifs fiscaux existants, ces derniers mettent en œuvre des stratégies fiscales de sorte à maximiser leurs revenus. / Taxation of athletes and professionals clubs. Whatever disciplines they promote, amateur associations are guarantors of the values conveyed through sport. They are the origin of all creations of sports clubs and sports hazard can lead a club to take the associative form due to financial or sporting events (sports relegation due to poor results, financial control DNCG...). The impact of taxation clubs and professional athletes plays a major role in the competitiveness of French sports clubs with their European neighbours. Indeed, the clubs support the wages of their players and offer net of tax salary. In addition, since the Bosman ruling in 1995, the football business is an "open" and sports activity exceptions are to be considered to preserve the French football. The organizers of competitions such as FIFA or UEFA recommend solutions. Sports companies must coexist with the largest European sports clubs but they must also maintain a link financial and sporting solidarity with sports associations.In addition to the different types of taxation that the athlete is subject we will discuss the consideration by the legislature of the problems of retirement professional. Despite existing tax arrangements, athletes are implementing tax strategies in order to maximize their income.

The increasing globalization of elite soccer match-play means that soccer players are likely to compete in hot, hypoxic and hot-hypoxic environments over a season. Soccer match-play studies have identified a marked decline in soccer-specific physical performance in the heat and hypoxia due to increasing body temperatures and a reduction in partial pressure of oxygen (PO2), respectively. As hot environments are more prevalent in elite soccer match-play, cooling strategies have been assessed within the literature in an attempt to alleviate these heat-induced- decrements. However, utilising a soccer match-play design makes environmental and interventional inferences difficult to ascertain, as a plethora of match factors and adaptive pacing strategies cause high variability in key physical performance measures within soccer match-play. Therefore, the three experiments within thesis aimed to assess the reliability and validity of a non-motorised treadmill (NMT) based soccer-specific simulation [intermittent Soccer Performance Test - (iSPT)], to enable the reliable investigation of environmental stress on soccer performance and the efficacy of pre- and half-time-cooling to attenuate any heat- induced-decrements. The purpose of experiment 1 was to investigate the reliability and validity of iSPT which utilised a novel speed component called a ‘variable run’. This speed component quantified the distance covered at a self-selected speed above the second ventilatory threshold (VT2speed), which attempted to delimit a ‘high-intensity’ threshold. Twenty male University soccer players completed one maximal oxygen (O2) uptake (V̇ O2max ) test, three familiarisation (FAM) sessions and one peak speed assessment (PSA) on the NMT, before completing the iSPT twice (iSPT1 and iSPT2). The total distance, sprint distance and high-speed distance covered were 8,952 ± 476 m, 1,000 ± 74 m and 2156 ± 140 m, respectively. No significant difference (p>0.05) was found between repeated trials of the iSPT for all physical performance measures and physiological responses. Reliability measures between iSPT1 and iSPT2 showed good agreement [Coefficient of variation: <4.6%; Intraclass correlation: >0.80] compared with statistical guidelines. Furthermore, the variable run phase showed high speed running capacity was significantly decreased (p<0.05) in the last 15 min compared to the first 15 min, showing parity with previous match-play data. Experiment 1 validated the iSPT as a NMT based soccer- specific simulation compared to previous match-play data, and is a reliable tool for assessing and monitoring the physical performance and physiological responses in soccer players. Successfully completing the aim of experiment 1 facilitated the quantification of hot (HOT), hypoxia (HYP) and hot-hypoxia (HH) mediated decrements on maximal soccer-specific performance in experiment 2. Twelve male University soccer players completed three FAM sessions, one PSA and four randomised crossover experimental trials of the intermittent Soccer Performance Test (iSPT) in normoxic-temperate (CON: 18oC 50% rH), HOT (30oC; 50% rH), HYP (1,000m; 18oC 50% rH) and HH (1,000m; 30oC; 50% rH). Physical performance and its performance decrements, body temperatures [rectal (Tre), skin (Tsk) and estimated muscle temperature (Tmu)], heart rate (HR), arterial blood oxygen saturation (SaO2), perceived exertion, thermal sensation (TS), body mass changes, blood lactate (Bla) and plasma volume were all measured. Performance decrements were similar in HOT and HYP [total distance (-4%), high- speed distance (~-8%) and variable run distance (~-12%) covered] and exacerbated in HH [total distance (-9%), high-speed distance (-15%) and variable run distance (-15%)] compared to CON. A 4% increase in peak sprint speed was present in HOT compared with CON and HYP and 7% greater in HH. The sprint distance covered was unchanged (p > 0.05) in HOT and HYP and only decreased in HH (-8%) compared with CON. Body mass (-2%), temperatures (+2- 5%) and TS (+18%) were altered in HOT. Furthermore, SaO2 (-8%) and HR (+3%) were changed in HYP. Similar changes in body mass and temperatures, HR, TS and SaO2 were evident in HH compared to HOT and HYP, however, Bla (p < 0.001) and plasma volume (p <0.001) were only significantly altered in HH. Perceived exertion was elevated (p < 0.05) by 7% in all conditions compared with CON. Regression analysis identified that absolute TS and absolute rise in Tsk and estimated Tmu (r = 0.82, r = 0.84 r = 0.82, respectively; p <0.05) predicted the hot-mediated-decrements in HOT. The hot, hypoxic and hot-hypoxic environments impaired physical performance during iSPT. Future interventions should address the increases in TS and body temperatures, to attenuate these decrements in physical performance. Experiment 3 of this thesis aimed to identify three pre- and half-time-cooling strategies to attenuate the heat-induced-decrements previously seen in experiment 2. Eight male University soccer players completed four randomised experimental trials of iSPT, three with cooling and one control (i.e. No pre- or half-time cooling: CON). The pre- and half-time-cooling interventions involved were 30-min or 15 min in duration, respectively. Ice slurry ingestion (SLURRY), ice packs (PACKS) covering the upper legs and mixed-methods (MM: PACKS and SLURRY) were utilised as the three cooling interventions. Physical performance and its performance decrements, body temperatures (Tre, Tsk and estimated Tmu), HR, perceived exertion, TS, body mass changes and Bla were all measured. Compared with CON, both PACKS and SLURRY pre-cooling significantly reduced (p > 0.05) central (Tre) and peripheral (Tsk and estimated Tmu) body temperatures prior to iSPT, respectively. However, body temperature and physical performance were unchanged during the first half of PACKS and SLURRY compared with CON. The MM pre-cooling significantly reduced all body temperatures and TS both prior to and during the first half which coincided with an improvement in total distance (+3%), high-speed distance (+4%) and variable run distance (+5%) covered. Half-time-cooling via PACKS, SLURRY and MM had no ergogenic effect (p> 0.05) upon physical performance in the second half, compared with CON. The 30 min of mixed-method pre-cooling, via ice packs placed upon the upper legs and ice slurry ingestion, significantly improved simulated soccer performance during the first half, however, future research should identify a valid half-time-cooling strategy to offer further improvements to physical performance in the second half. The main findings within this thesis revealed that the iSPT showed validity with previous soccer match-play data and strong reproducibility between two tests (iSPT1 and iSPT2). Furthermore, the variable run component showed efficacy as sensitive measure of the decrements in high-speed running capability. As the iSPT demonstrated low test-retest error compared with the statistical guidelines and previous NMT based soccer-specific simulations, any changes to physical performance can be attributed to an intervention and not the variability of the measure, unlike in soccer match-play situations. No difference was seen for all physical performance measures in both HOT and HYP, however, the heat and hypoxic-induced- decrements stem from increasing body temperatures and changes to both SaO2 and HR, respectively. Such decrements may have a detrimental effect upon the match outcome. These heat-induced-decrements were attenuated in the first half after 30 min of mixed-methods pre- cooling, however, the 15 min of mixed-methods half-time-cooling did not significantly improve any physical performance measure in the second half. The mixed-method pre-cooling strategy tested within this thesis could go some way in maintaining physical performance during the first half of soccer match-play in hot environments (~30oC). However, future laboratory based research within a controlled environment should look to assess different combinations, times and strategies of cooling which may be applicable to the time constraints associated with elite soccer.