Despite the abundance of research conducted into the effects of exercise on mucosal immunity the results remain controversial. Much of the inconsistencies arise from the exercise protocols, the participants studied and their nutritional status, as well as methodological and analytical differences. The purpose of this thesis was to examine the influence of some of these factors, and to investigate potential means of enhancing the mucosal immune response to exercise. In study 1 (Chapter 3) it was shown that a fed or fasted state 2 h prior to exercise had no effect on the s-IgA concentration or secretion rate during prolonged exercise. However, when participants were fed during exercise (Chapter 4), the secretion rate of salivary antimicrobial proteins lysozyme and a-amylase increased, but sIgA remained unchanged. These changes were likely due to the activation of mechanical and gustatory receptors leading to a reflex stimulation of protein secretion via the autonomic nerves, rather than changes in stress hOnliones, since cortisol did not change significantly during exercise. Study 3 (Chapter 5) extended these findings where it was demonstrated that chewing flavoured gum during exercise enhanced lysozyme and a-amylase secretion but resulted in a small reduction in s-IgA secretion rate. Salivary antimicrobial proteins are affected by the exercise intensity since both s-IgA and lysozyme secretion rate increased post -exercise following an incremental test to exhaustion, but not after exercise at 50% Y02max. Moreover, lysozyme secretion rate was also elevated following exercise at 75% Y02mru<, whereas s-IgA remained unchanged. These effects are thought to be mediated by increased sympathetic nervous system activity reflected by the concomitant increases in (lamylase and chromogranin A, rather than the hypothalamic-pituitary-adrenal axis. Resting mucosal immunity exhibits significant gender differences. In study 1 (Chapter 3) s-IgA concentration, secretion rate and osmolality were found to be lower in females than in males at rest. In addition, saliva flow rate was found to be lower in females compared with males in study 5 (Chapter 7). However, these differences did not appear to influence the salivary responses to acute exercise or exercise training. Chronic exercise training in elite male and female swimmers resulted in lower levels of s-IgA secretion rate following periods of intense training prior to competition compared with post-competition (Chapter 7), but these levels were not directly associated with reported episodes of respiratory illness.

L’objectif de cette thèse est d’étudier les évolutions morphologiques des sportifs de haut niveau et d’identifier les liens structurant performance et caractéristiques anthropométriques. Les différentes études constituant cette thèse analysent la performance de haut niveau par son versant morphologique et selon différents niveaux de démonstration. Dans un premier temps, nous montrons des évolutions différenciées entre SHN et individus de la population générale (études 1 et 2), présupposant que les SHN tirent des avantages de leurs caractéristiques anthropométriques. Puis, nous mettons en évidence les liens directs entre les caractéristiques anthropométriques et la performance en athlétisme et dans le rugby (études 2 et 5) : les équipes de rugby disposant d’avants plus lourds et d’arrières plus grands sont plus performantes que les autres. En athlétisme, les coefficients allométriques calculés montrent l’impact du poids selon la distance de course et le sexe suggérant une possible marge de progression des caractéristiques anthropométriques pour les athlètes féminines. Le 3ème niveau de démonstration met en exergue l’existence de couples [morphologies optimales - performances optimales+, d’attracteurs biométriques bénéfiques au scoring en basketball (étude 3), et d’optima d’IMC avec leurs intervalles de performance selon la distance de course (études 4, 5 et 6). Poids, taille et IMC sont des indicateurs pertinents puisqu’ils permettent de spécifier les paramètres des athlètes entre les différentes épreuves (gradients morphologiques en athlétisme suivant le spectre des distances, à l’instar des gradients énergétiques) mais également selon leur niveau (gradient de poids et taille inverses entre courses de fond et sprints). Ces trois indicateurs morphologiques dévoilent également des différenciations selon les spécificités de poste. Mises en comparaison, les évolutions de poids et de taille montrent des croissances asynchrones révélatrices d’atypicité. L’IMC, très loin de sa fonction première de mesure de la corpulence et de l’obésité, doit être redéfini comme un indicateur utile de la performance de haut niveau. En effet, il révèle le compromis entre puissance, capacité énergétique et organisation de la structure corporelle efficiente chez les SHN. Dans l’exécution sportive, l’ensemble du corps est en action, et poids, taille et IMC prennent en compte la globalité de l’athlète qui se meut. Certains constats émanant des conclusions de cette thèse font surgir de nouvelles réflexions dans la compréhension de la performance et vont générer la mise en place de protocoles expérimentaux. Les gabarits sont l’expression de la performance autant que l’organisation à partir de laquelle se réalise cette dernière. Les résultats de cette thèse, fondés sur l’analyse de bases de données conséquentes, apportent une nouvelle vision sur les optimisations morphologiques. Dans le dessein de performance, il est nécessaire de connaître les optimisations établies chez les meilleurs mondiaux afin de situer les athlètes dans leurs champs morphologiques mais aussi de leur permettre d’évoluer vers la meilleure adaptation anthropométrique, spécifique de leur activité. / The purpose of this thesis is to study the morphological changes of top athletes and identify structural links between performance and anthropometric characteristics. This thesis is comprised of various studies that analyze the highest level of performance by morphological aspect and different levels of proof. At first, we show differentiated changes between high level athletes and individuals in the general population (Studies 1 and 2), presupposing that athletes draw benefits from their anthropometric characteristics. Then we highlight the direct links between anthropometric characteristics and performance in track and field athletes and rugby players (studies 2 and 5): rugby teams with heavier forwards and taller backs are more successful than others. In track and field, calculated allometric coefficients show the impact of mass depending on the distance of the race and sex, suggesting a possible anthropometric progression margin for female athletes. The third level of supporting evidence, highlights the existence of couples [optimal morphologies - optimal performance], biometric attractors beneficial in scoring in basketball (Study 3), and BMI optimum with performance intervals in race distance (studies 4, 5 and 6). Mass, height and BMI are relevant indicators used to specify athletes between different events (morphological gradients in track and field following the spectrum of distances, like energy gradients) but also according to their level (inverse gradient between mass and height according to middle and long distances and sprints). These three indicators also reveal morphological differentiation depending on the specific position. Being compared, changes in mass and height show asynchronous growth indicative of atypicity. Independent from BMI’s primary function of measuring the body size and obesity, it should be refined as a useful indicator of high level performance. Indeed, it reveals trade-off between power, energy capacity and organization of efficient body structure for high level athletes. In athletic performance, the whole body is in action, and mass, height and BMI take into account the entire athlete who moves. Some conclusions from the findings of this thesis arise new thoughts in the performance understanding and will generate the development of experimental protocols. Physiques are the expression of the performance as well as the organization from which it is realized. The results of this thesis, based on the analysis of consistent databases, provide a new vision on morphological optimizations. For the purpose of performance, it is necessary to know the optimizations established in order to situate athletes in their morphological fields, but also enable them to move towards better anthropometric adaptation specific of their activities.

Performance and exercise capacity in prolonged continuous exercise has been shown to be enhanced by the ingestion of dilute (-6%) carbohydrate-electrolyte (CHO-E) solutions during exercise. There is a wealth of literature on the effects of CHO-E solutions on prolonged, continuous exercise however this is not the case for highintensity intermittent exercise. One reason for this is the difficulty of replicating the demands of multiple-sprint sports within the laboratory. The development of the Loughborough Intermittent Shuttle Running Test (LIST), a protocol that simulates the physiological demand of multiple-sprint sports, has allowed for further study in this area. Sports drinks contain a variety of different types of carbohydrate, including synthetic polymers of maltodextrins. The rationale for these is two-fold; firstly there is some evidence to suggest that these glucose polymers of low osmolality may empty faster than isoenergetic glucose solutions especially at dilute (-6%) concentrations. Secondly CHO-E solutions formulated from maltodextrins with low dextrose equivalents are less acidogenic and have lower cariogenic potential than simple glucose solutions, thus making them preferable for tooth health. Therefore the purpose of this thesis was to examine the effects of a 6.4% hypotonic synthetic polymer maltodextrin CHO-E solution on muscle metabolism and physiological performance during prolonged high-intensity intermittent running (LIST). This thesis contains four experimental studies. From the results of study 1 it was concluded that the ingestion of a 6.4% hypotonic CHO-E solution provided no ergogenic benefit to running capacity during the LIST despite blood and hormonal data suggesting that the solution was effective at delivering glucose. As isotonic CHO-E solutions have shown to have ergogenic properties during LIST running the purpose of study 2 was to compare isoenergetic hypotonic and isotonic CHO-E solutions during LIST running. The results from this study suggested that performance, as measured by exercise capacity and sprint speed, was not affected by either treatment. In study 3 the protocol was modified to extend the exercise duration so that a greater demand was placed on the subjects' glycogen reserves. The results from this study further confirmed that exercise capacity in LIST running was not influenced by CHO provision during exercise however the habitual CHO intake of the subjects may have masked any ergogenic properties of the CHO-E solution and led to increased performance in the control trials. In the final study the subjects' pre-trial exercise and dietary CHO intake was manipulated to increase endogenous glycogen concentrations. The results showed that in these subjects the ingestion of a 6.4% hypotonic CHO-E solution increased exercise capacity during the LIST by 21%. Muscle biopsy analyses revealed a lower net muscle glycogen utilisation in the CHO trial post-90 min (p=0.07). There is evidence in the literature to suggest that there is an ergogenic effect of CHO ingestion during the LIST. However the results presented in this thesis suggest that when endogenous glycogen stores are moderate the ingestion of a CHO-E solution may suppress lipid oxidation without a concomitant increase in CHO oxidation and thus LIST capacity is not enhanced. In contrast, when endogenous glycogen concentrations are elevated through dietary manipulation there is an ergogenic benefit from the ingestion of hypotonic CHO-E solutions during LIST exercise.

Einleitung: Epidemiologische Studien zeigen den langfristigen Nutzen körperlicher Aktivität zur Prävention neurologischer Erkrankungen und kognitiver Defizite im Alter auf. Sportliche Betätigung kann jedoch, vor allem bei Ausübung von Kontaktsportarten, auch akute und chronische neuronale Schädigungen durch häufige mechanische Beeinflussungen des Gehirns hervorrufen. NSE und S-100B sind laborchemische Marker, die im Rahmen der Diagnostik von Hirnschädigungen zum Einsatz kommen. Einige Forschungsarbeiten fanden erhöhte Konzentrationen dieser Biomarker nach sportlichen Belastungen ohne offensichtliches Vorliegen von traumatischen Ereignissen oder neurologischer Beeinträchtigungen. Daher stellt sich die Frage, ob entsprechende Norm- bzw. Cut-Off-Werte für NSE und S-100B universell im klinischen Alltag geeignet sind oder durch belastungsinduzierte Einflüsse einer differenzierteren Beurteilung unterzogen werden sollten. In vorliegender Arbeit wird diese Fragestellung anhand der klassischen Ausdauersportarten Laufen und Radfahren untersucht. Ergebnisse und Diskussion: Zunächst erfolgte der Nachweis für die Reproduzierbarkeit von NSE bei Ausdauersportlern für Ruhe- und Belastungsbedingungen. Es wurden keine signifikanten Unterschiede für NSE im Belastungsvergleich von Radfahren und Laufen, wie beim Vergleich verschiedener Laufintensitäten im zeitlichen Verlauf festgestellt. Die denkbare Einflussnahme beim Laufen durch leichte Erschütterungen des Gehirns basierend auf dem Impact beim Bodenkontakt des Fußes, ist offensichtlich irrelevant. Physischer Stress, der durch einen Marathonlauf verursacht wird, führt offensichtlich in der Akutphase nach dem Wettkampf zu einem signifikanten Anstieg von NSE und S-100B, welche im späteren Verlauf wieder auf das Ausgangsniveau abfallen. Dies ist unabhängig von Alter und Geschlecht. Über dem Normwert für Gesunde liegende NSE-Konzentrationen nach einer Marathonbelastung, haben offensichtlich keine pathophysiologischen Auswirkungen oder klinische Korrelationen. In der klinischen Praxis sollten erhöhte NSE-Werte entsprechend vorsichtig interpretiert werden. Weitere marathonspezifische Faktoren wie Trainingshäufigkeit, Renneinteilung, Wetterbedingungen und Dysnatriämie, aber auch Alter und Geschlecht zeigten keine Zusammenhänge hinsichtlich der Serum-Konzentration von NSE und S-100B. Ebenfalls fanden sich keine signifikanten Veränderungen bei der Klassifizierung von Notfallpatienten bei Laufveranstaltungen bezüglich Diagnose und Streckenlängen. Fortführende Forschungsaktivitäten mit hohen Fallzahlen sind notwendig, um die Wertigkeit der beiden biochemischen Labormarker unter Einfluss körperlicher Aktivität herauszustellen.:1. Einleitung und allgemeine Problemstellung 1 1.1 Einleitung 1 1.2 Ziele der Arbeit 4 2. Theoretische Grundlagen 5 2.1 Theoretische Grundlagen zu NSE 5 2.2 Theoretische Grundlagen zu S-100B 8 2.3 Einfluss sportlicher Belastungen auf NSE 9 2.4 Einfluss sportlicher Belastungen auf S-100B 10 3. Grundlegende Aspekte zur Methodik dieser Arbeit 12 3.1 Blutanalytik 13 3.2 Messverfahren NSE und S-100B 13 3.3 Ausschluss Hämolyse 14 3.4 Plasmavolumenkorrektur 17 3.5 Leistungsdiagnostik 18 3.6 Auswertung und Statistik 19 4. Teilstudie 1 - Methodische Untersuchungen 21 4.1 Reproduzierbarkeit von NSE unter Ruhe- und Belastungsbedingungen 21 4.1.1 Einleitung 21 4.1.2 Methoden 21 4.1.2.1 Probanden 21 4.1.2.2 Studiendesign 23 4.1.3 Ergebnisse 24 4.1.4 Diskussion 30 4.2 Pilotstudie zur In-vivo-Bestimmung von zerebralen S-100B mittels 1H-Magnetresonanzspetroskopie 35 4.2.1 Einleitung 35 4.2.2 Methoden 35 4.2.2.1 Probanden 35 4.2.2.2 Messverfahren 36 4.2.2.3 Studiendesign 39 4.2.3 Ergebnisse 39 4.2.4 Diskussion 41 5. Teilstudie 2 - Untersuchungen zum Einfluss sportlicher Belastung und NSE 47 5.1 Belastungsart und NSE 47 5.1.1 Einleitung 47 5.1.2 Methoden 47 5.1.2.1 Probanden 47 5.1.2.2 Studiendesign 48 5.1.3 Ergebnisse 50 5.1.4 Diskussion 54 5.2 Belastungsintensität und NSE 56 5.2.1 Einleitung 56 5.2.2 Methoden 56 5.2.2.1 Probanden 56 5.2.2.2 Studiendesign 57 5.2.3 Ergebnisse 57 5.2.4 Diskussion 61 6. Teilstudie 3 - Untersuchungen zum Einfluss von Marathonbelastungen auf NSE und S-100B 62 6.1 Einleitung 62 6.2 Methoden 64 6.2.1 Probanden 64 6.2.2 Sonstige Blutparameter 69 6.2.3 Studiendesign 71 6.3 Ergebnisse 71 6.3.1 Zeitlicher Verlauf 71 6.3.2 Geschlecht und NSE 73 6.3.3 Einfluss des Alters 75 6.3.4 Sportanamnestische Daten 79 6.3.5 Renntaktik 81 6.3.6 Wetterbedingungen 82 6.3.7 Dysnatriämie 84 6.3.8 NSE und S-100B im Zusammenhang mit weiteren belastungsspezifischen Laborparametern 85 6.4 Diskussion 91 6.4.1 Zeitlicher Verlauf 91 6.4.2 Alter und Geschlecht 93 6.4.3 Trainingshäufigkeit und -umfang 94 6.4.4 Renneinteilung 95 6.4.5 Elektrolytstörungen 97 6.4.6 NSE und S-100B im Zusammenhang mit weiteren belastungsspezifischen Laborparametern 98 7. Teilstudie 4 - Untersuchungen bei laufassoziierten Notfällen 104 7.1 Laufassoziierte Notfälle und NSE 104 7.1.1 Einleitung 104 7.1.2 Methoden 105 7.1.2.1 Probanden 105 7.1.2.2 Studiendesign 105 7.1.3 Ergebnisse 106 7.1.4 Diskussion 108 7.2 Einzelfallstudie 111 7.2.1 Einleitung 111 7.2.2 Methoden 111 7.2.2.1 Proband 111 7.2.2.2 Studiendesign 112 7.2.3 Ergebnisse 112 7.2.4 Diskussion 114 8. Abschließende Diskussion 118 9. Zusammenfassung 123 10. Literaturverzeichnis 125 11. Anhang 140 12. Danksagung 145 13. Eidesstattliche Erklärung 146 / Introduction: Epidemiological studies show long term benefits of exercise and sports for neurological diseases and cognitive deficits in elderly populations. In contact sports however also acute and chronic neuronal impairment of the brain itself caused by repetitive mechanical impact have been found. NSE and S-100B are biochemical markers used in diagnostics of brain injuries. Through several studies found increased values of theses markers after exercise without evident existence of traumatological occasion or neurological impairment. Whether NSE and S-100B and its corresponding reference- and cut-off-values can be applied in clinical routine or if exercise-induced effects apply for a more sophisticated evaluation, should herein be examined by the effects of traditionally endurance sports running and cycling. Results and discussion: At first the proof for repeatability of NSE in endurance sportsmen at rest and during physical activity was given. When comparing the effects of cycling and running as well as different training intensities in these sports, no significant changes could be noticed. Possible causes of elevated NSE due to slight concussions of the brain based on repetitive impact forces during running are obviously irrelevant. Running a marathon tends to result in a significant raise of NSE and S-100B in the acute period after the competition. The further process shows a decline to the base level independent of age or gender. NSE values above norm values after completing a marathon have clearly no pathophysiological effects or clinical correlates. Thus high NSE- concentrations should be interpreted with caution in clinical praxis. Further marathon specific factors like training, pacing strategy, weather conditions, dysnatraemia show no significant correlations with NSE or S-100B. Clustering emergency cases by diagnosis and running distance revealed no relationships to NSE. Further research with larger populations is necessary, to emphasize the relevance for NSE and S-100B during exercise.:1. Einleitung und allgemeine Problemstellung 1 1.1 Einleitung 1 1.2 Ziele der Arbeit 4 2. Theoretische Grundlagen 5 2.1 Theoretische Grundlagen zu NSE 5 2.2 Theoretische Grundlagen zu S-100B 8 2.3 Einfluss sportlicher Belastungen auf NSE 9 2.4 Einfluss sportlicher Belastungen auf S-100B 10 3. Grundlegende Aspekte zur Methodik dieser Arbeit 12 3.1 Blutanalytik 13 3.2 Messverfahren NSE und S-100B 13 3.3 Ausschluss Hämolyse 14 3.4 Plasmavolumenkorrektur 17 3.5 Leistungsdiagnostik 18 3.6 Auswertung und Statistik 19 4. Teilstudie 1 - Methodische Untersuchungen 21 4.1 Reproduzierbarkeit von NSE unter Ruhe- und Belastungsbedingungen 21 4.1.1 Einleitung 21 4.1.2 Methoden 21 4.1.2.1 Probanden 21 4.1.2.2 Studiendesign 23 4.1.3 Ergebnisse 24 4.1.4 Diskussion 30 4.2 Pilotstudie zur In-vivo-Bestimmung von zerebralen S-100B mittels 1H-Magnetresonanzspetroskopie 35 4.2.1 Einleitung 35 4.2.2 Methoden 35 4.2.2.1 Probanden 35 4.2.2.2 Messverfahren 36 4.2.2.3 Studiendesign 39 4.2.3 Ergebnisse 39 4.2.4 Diskussion 41 5. Teilstudie 2 - Untersuchungen zum Einfluss sportlicher Belastung und NSE 47 5.1 Belastungsart und NSE 47 5.1.1 Einleitung 47 5.1.2 Methoden 47 5.1.2.1 Probanden 47 5.1.2.2 Studiendesign 48 5.1.3 Ergebnisse 50 5.1.4 Diskussion 54 5.2 Belastungsintensität und NSE 56 5.2.1 Einleitung 56 5.2.2 Methoden 56 5.2.2.1 Probanden 56 5.2.2.2 Studiendesign 57 5.2.3 Ergebnisse 57 5.2.4 Diskussion 61 6. Teilstudie 3 - Untersuchungen zum Einfluss von Marathonbelastungen auf NSE und S-100B 62 6.1 Einleitung 62 6.2 Methoden 64 6.2.1 Probanden 64 6.2.2 Sonstige Blutparameter 69 6.2.3 Studiendesign 71 6.3 Ergebnisse 71 6.3.1 Zeitlicher Verlauf 71 6.3.2 Geschlecht und NSE 73 6.3.3 Einfluss des Alters 75 6.3.4 Sportanamnestische Daten 79 6.3.5 Renntaktik 81 6.3.6 Wetterbedingungen 82 6.3.7 Dysnatriämie 84 6.3.8 NSE und S-100B im Zusammenhang mit weiteren belastungsspezifischen Laborparametern 85 6.4 Diskussion 91 6.4.1 Zeitlicher Verlauf 91 6.4.2 Alter und Geschlecht 93 6.4.3 Trainingshäufigkeit und -umfang 94 6.4.4 Renneinteilung 95 6.4.5 Elektrolytstörungen 97 6.4.6 NSE und S-100B im Zusammenhang mit weiteren belastungsspezifischen Laborparametern 98 7. Teilstudie 4 - Untersuchungen bei laufassoziierten Notfällen 104 7.1 Laufassoziierte Notfälle und NSE 104 7.1.1 Einleitung 104 7.1.2 Methoden 105 7.1.2.1 Probanden 105 7.1.2.2 Studiendesign 105 7.1.3 Ergebnisse 106 7.1.4 Diskussion 108 7.2 Einzelfallstudie 111 7.2.1 Einleitung 111 7.2.2 Methoden 111 7.2.2.1 Proband 111 7.2.2.2 Studiendesign 112 7.2.3 Ergebnisse 112 7.2.4 Diskussion 114 8. Abschließende Diskussion 118 9. Zusammenfassung 123 10. Literaturverzeichnis 125 11. Anhang 140 12. Danksagung 145 13. Eidesstattliche Erklärung 146

Prolonged strenuous exercise affects the circulating numbers and functions of immune cells. These effects are thought to be largely mediated by the actions of elevated circulating stress hormones and alterations in regulatory cytokines. Although the effects of a single acute bout of exercise on immune system function are quite well established, it is still not clear how time of day and repeated bouts of prolonged exercise on the same day influence immune function. It is of particular interest to understand the effects of nutritional supplementation on immunoendocrine responses. Therefore, the aims of the studies described in this thesis were to determine the effects of two bouts of prolonged cycling and carbohydrate supplementation on immunoendocrine responses. The saliva collection study showed that the use of a swab for collecting saliva is not an ideal method because it affects the results of saliva composition (Chapter 4). The comparison of the effects of exercise at different times of day on immunoendocrine responses showed that a single bout of prolonged exercise performed in the afternoon induces a larger perturbation in the redistribution of leukocytes into the circulation than an identical bout of morning exercise, which maybe due to higher hypothalamic-pituitaryadrenal (HP A) activation and. circadian rhythms. However, in terms of oral mucosal immunity, performing prolonged cycling at different times of day does not differently affect the salivary responses. The second compared with the first of two bouts of prolonged exercise on the same day induces a greater HP A activation, a larger leukocyte trafficking into the circulation, a decreased neutrophil degranulation response to lipopolysaccharide (LPS) on per cell basis and a lower saliva flow rate, but does not increase plasma interleukin-6 (IL-6), or change saliva immunoglobulin A (slgA) secretion rate (Chapter 5). Furthermore, carbohydrate (CHO) ingestion during any period of two bouts of prolonged exercise shows limited beneficial effect in blunting these higher responses in the second exercise bout compared with the first identical exercise bout on the same day (Chapter 6, 7 and 8). The determination of the effects of CHO ingestion on exercise-induced immunoendocrine responses showed that when two bouts of exercise are performed on the same day, the greater benefit in terms of circulating immunoendocrine responses is obtained by feeding CHO at the earliest opportunity (Chapter 6, 7 and 8). A 3-h interval is insufficient for recovery of leukocyte mobilisation and neutrophil function from the impact of previous exercise whether subjects consumed placebo or CHO during exercise or recovery (Chapter 5, 6, 7 and 8). However, an 18-h interval is sufficient for full recovery of all immunoendocrine variables that were measured in this thesis from the impact of two bouts of prolonged exercise (Chapter 8).

Le développement futur des performances sportives est un sujet de mythe et de désaccord entre les experts. Un article, publié en 2004, a donné lieu à un vif débat dans le domaine universitaire [1]. Il suggère que les modèles linéaires peuvent être utilisés pour prédire -sur le long terme- la performance humaine dans les courses de sprint. Des arguments en faveur et en défaveur de cette méthodologie ont été avancés par différent scientifiques et d’autres travaux ont montré que le développement des performances est non linéaire au cours du siècle passé [2, 3]. Une autre étude a également souligné que la performance est liée au contexte économique et géopolitique [4]. Dans ce travail, nous avons étudié les frontières suivantes : le développement temporel des performances dans des disciplines Olympiques et non Olympiques, avec le vieillissement chez les humains et d’autres espèces (lévriers, pur sangs, souris). Nous avons également étudié le développement des performances d’un point de vue plus large en analysant la relation entre performance, durée devie et consommation d’énergie primaire. Nous montrons que tous ces dévelopments sont limitées dans le temps [5, 6, 7] et que les modèles linéaires introduits précédemment sont de mauvais prédicteurs des phénomènes biologiques et physiologiques étudiés. Trois facteurs principaux et directs de la performance sportive sont l’âge [8, 9], la technologie [10, 11] et les conditions climatiques (température) [12]. Cependant, toutes les évolutions observées sont liées au contexte international et à l’utilisation des énergies primaires, ce dernier étant un paramètre indirect du développement de la performance. Nous montrons que lorsque les indicateurs des performances physiologiques et sociétales -tels que la durée de vie et la densité de population- dépendent des énergies primaires, la source d’énergie, la compétitioninter-individuelle et la mobilité sont des paramètres favorisant la réalisation de trajectoires durables sur le long terme. Dans le cas contraire, la grande majorité (98,7%) des trajectoires étudiées atteint une densité de population égale à 0 avant 15 générations, en raison de la dégradation des conditions environnementales et un faible taux de mobilité. Ceci nous a conduit à considérer que, dans le contexte économique turbulent actuel et compte tenu de la crise énergétique à venir, les performances sociétales et physiques ne devraient pas croître continuellement. / The development of sport performances in the future is a subject of myth and disagreement among experts. In particular, an article in 2004 [1] gave rise to a lively debate in the academic field. It stated that linear models can be used to predict human performance in sprint races in a far future. As arguments favoring and opposing such methodology were discussed, other publications empirically showed that the past development of performances followed a non linear trend [2, 3]. Other works, while deeply exploring the conditions leading to world records, highlighted that performance is tied to the economical and geopolitical context [4]. Here we investigated the following human boundaries : development of performances withtime in Olympic and non-Olympic events, development of sport performances with aging among humans and others species (greyhounds, thoroughbreds, mice). Development of performances from a broader point of view (demography & lifespan) in a specific sub-system centered on primary energy were also investigated. We show that all these developments are limited with time [5, 6, 7] and that previously introduced linear models are poor predictors of biological and physiological phenomena. Three major and direct determinants of sport performance are age [8, 9], technology [10, 11] and climatic conditions (temperature) [12]. However, all observed developments are related to the international context including the efficient use of primary energies. This last parameter is a major indirect propeller of performance development. We show that when physiological and societal performance indicators such as lifespan and population density depend on primary energies, the energy source, competition and mobility are key parameters for achieving longterm sustainable trajectories. Otherwise, the vast majority (98.7%) of the studied trajectories reaches 0 before 15 generations, due to the consumption of fossil energy and a low mobility rate. This led us to consider that in the present turbulent economical context and given the upcoming energy crisis, societal and physical performances are not expected to grow continuously.

Notre objectif à court terme est d’établir des courbes de référence Française de la densité osseuse (DMO) et de la composition corporelle masculine une fois que nous aurons toutes les données issues de tous les centres. Nous avons donc réalisé deux études préliminaires dans le cadre de ce projet dont les objectifs sont les suivants :A) Etudier les déterminants de la DMO corps entier mais aussi spécifiques de site osseux en lien avec les mesures de composition corporelle, de force musculaire et de l’activité physique chez l’homme jeune B) Cross-calibration in vitro des paramètres de densité osseuse et de composition corporelle mesurés par l’absorptiométrie bi-photonique à rayons X (DXA) afin d’établir les facteurs correctifs à appliquer in vivo dans le cadre de notre projet de courbe de référence chez l’homme jeune.Grâce à la DXA, notre étude a confirmé que la masse maigre était le facteur le plus important associé aux paramètres de la DMO sur tous les sites osseux étudiés et que la masse grasse avait un impact négatif sur la DMO. Aucune association n'a été trouvée entre activité physique et DMO. La force de préhension était significativement mais modérément corrélée avec la DMO. Concernant la cross-calibration, les résultats ont montré que l’oscillation des résultats entre les différents DXA des centres est un sujet de préoccupation pour les études multicentriques et en particulier pour l’évaluation de la composition corporelle. La cross-calibration nous a permis de calculer les facteurs correctifs à appliquer sur les données issues des centres impliqués. Afin de limiter ces variations, il serait souhaitable de mettre au point un fantôme corps entier standard qui serait utilisé pour les études multicentriques. / Our short-term goal is to establish French reference curves of bone mineral density (BMD) and body composition once we have data from all centers. We have therefore carried out two preliminary studies for this project whose objectives are as follows: A) To study the determinants of whole body BMD but also bone site specific in relation to measurements of body composition, muscle strength and physical activity in young men B) Cross-calibration in vitro of bone mineral density and body composition parameters measured by dual energy X-ray absorptiometry (DXA) in order to establish in vivo the correction factors to be used in our baseline project in young men. Using DXA, our study confirmed that lean mass was the most important factor associated with BMD parameters at all bone sites and fat mass had a negative impact on BMD. Grip strength was significantly but moderately correlated with BMD at all sites. No association was found between physical activity and BMD. Regarding cross-calibration, the results showed that the oscillation of the results between the different DXA centers is a problem for multicenter studies and in particular for the evaluation of body composition. Cross-calibration allowed us to calculate the corrective factors to be applied to the data from the centers involved. In order to limit these variations, it would be desirable to develop a standard whole-body phantom that would be used for multicentre studies.