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International audience; Cette communication a eu pour objectif de resituer, à partir de données quantitatives la préparation mentale dans le champ du sport de haut niveau. 2 enquêtes sociologiques sur les conditions de préparation des sportifs ayant participé aux jeux ont été mobilisées. Les premiers constats de l’enquête Rio datant de 2016 ont été présentés, puis dans un second temps, une comparaison a été effectuée avec des données plus récentes, issues de l’enquête Tokyo (2021). La préparation mentale est de plus en plus intégrée par les sportifs et les sportives. Les femmes font plus de préparation mentale que les hommes.

International audience

International audience; The aim of this study was to compare the speed, oxygen uptake (VO2 consumption), blood lactate concentration ([La]b), and stroke rate (SR) in sprint and middle-distance swimmers. Seven male elite middle-distance swimmers (performance level=89% of the world record) and seven male sprint swimmers (performance level=88% of the world record) were recruited. Ventilatory, metabolic and kinematic parameters were obtained during a 6 x 300-m incremental swimming exercise to exhaustion. VO2 kinetics were compared between groups using a 500-m interval training set (IT-500) swum at the lactate threshold (LT). Speed at VO2max was faster for the middle-distance swimmers (1.51 ± 0.02 m.s-1) than the sprinters (1.34 ± 0.07 m.s-1). Speed at LT was also faster for the middle-distance swimmers (3.1 ± 1.2 mmol.L-1; v LT = 1.46 ± 0.01 m•s-1, equivalent to 96.7 ± 0.5% of vVO2max) than the sprinters (4.5 ± 1.5 mmol.L-1; v LT = 1.22 ± 0.06 m•s-1, 91 ± 1.9% of vVO2max; P < 0.01). The middle-distance swimmers had a higher stroke rate at LT (36.7 ± 4.5 vs. 30.3 ± 0.7 s.min-1) and consumed a larger VO2max fraction (95 ± 2 vs. 84 ± 5% of VO2max; P < 0.01). A significant positive correlation was observed between ΔVE and ΔSR (r² = 0.93, P < 0.01) in the middle-distance swimmers during the IT-500, whereas a negative relationship was observed with Δstroke length (r² = 0.81, P < 0.01). The middle-distance swimmers were typically 10-15% faster at the lactate threshold and at the maximal oxygen uptake. In contrast, the blood lactate concentration was 40% higher in the sprint swimmers but the stroke rate was 15% lower at the lactate threshold.

International audience; Introduction. Training quantifications are valuable for monitoring and prescribing elite swimmers’ training and are indispensable in mathematical models that attempt to accurately predict performance. Modelling the association of training with performance raises an important issue: how should we account for volumes at different training intensities? Mujika et al. (1996) constructed a training load by adding weighted (by a priori constants representing energetic intensities) volumes from each intensity. Avalos et al. (2003) computed a training load as the sum of normalised training intensities. Here we compared the predictive accuracy of these methods to others based on: a/ alternative normalisations, b/ summary scores derived from data, and c/ machine learning techniques, with recognised predictive qualities, such as PLS.Methods. Training volumes at eight intensity levels (in kilometres and minutes per week, for in-water and dry-land workouts, respectively) and performances in competition of 138 professional French swimmers were collected during 20 seasons. Training intensities were determined using measurements of blood lactate concentrations. We assumed that swimmers may react differently to the same training and over time, thus we used mixed-effects models adjusted for sex, age, swimming distance and event specialty. The comparison criterion was the cross-validated prediction error.Results. Summary scores for three training loads (low-intensity/high-intensity/dry-land workouts) with data derived weights showed the best results (mean cross-validated prediction error ± SD were 0.60±0.89, 0.50±0.62 and 0.10±0.19 for sprint, mid- and long-distances, respectively). However, cross-validated prediction errors were close relative to their variances, which were high.Conclusions. The use of complex machine learning techniques did not lead to more accuracy in predicting performance. Although data derived scores showed the lowest prediction error, the statistical variability was too high for being conclusive. A possible explanation is that the lactate sensitivity to extraneous factors (mode of exercise, technique quality of training, diet or sleep quality prior to test) and the subject-specific variations in lactate thresholds introduce not negligible measurement error. As practical recommendation, we suggest completing lactate measurements with athlete/coach questionnaires to better assess the physiological stress associated with the training load. Also, errors-in-variables models might be more appropriated.

International audience; Background/Aim: Strenuous endurance training required to participate in the highest sports level has been associated with deleterious effects on elite athletes' health and cardiac abnormalities. We aimed to describe overall mortality and main causes of deaths of male French rowers participating in at least one Olympic Game (OG) from 1912 to 2012 in comparison with the French general population.Methods: Identity information and vital status of French Olympic rowers were validated by National sources from 1912 to 2013 (study's endpoint) among 203 rowers; 52 out of 255 (20.3%) were excluded because their vital statuses could not be confirmed. Main causes of deaths were obtained from the National registry from 1968 up to 2012. Overall and disease-specific mortalities were calculated through standardised mortality ratios (SMRs) with its 95% confidence intervals (CIs). The overall mortality was calculated for the whole rowers' cohort (PT) and for two periods apart: (P1) including rowers from 1912 to 1936 OG, a cohort in which all rowers have deceased and (P2) considering rowers from 1948 to 2012 OG.Results: Among the 203 rowers analysed, 46 died before the study's endpoint, mainly from neoplasms (33%), cardiovascular diseases (21%) and external causes (18%). PT demonstrates a significant 42% lower overall mortality (SMR: 0.58, 95% CI: 0.43–0.78, p

International audience; In a context of morphological expansion of the general population, how do athletes follow such a pattern of anthropometric growth? Is there any relation to performance? Biometric data including mass, height, body mass index (BMI) and age were collected for 50,376 American athletes representing 249,336 annual performers playing in professional baseball, football, ice hockey and basketball. Distributions by mass in National Football League (NFL) players are described by periods. Field goals have been studied in relation to players’ height in the National Basketball Association (NBA). Between 1871 and 2011, athletes from the four sports have increased significantly in mass, height and BMI, following a multi-exponential function series. Consequently, biometric differences between athletes and the general population are increasing gradually. Changes in the mass distribution within the NFL show the emergence of a biometrical specificity in relation to the field position. At the professional level, performance remains structured around precise biometric values. In the NBA, a height-attractor at 201.3 ± 6.3 cm for the best scorers is invariant, regardless of the level of play. These results suggest that laws of growth and biometrics drive high-level sport and organise performance around the specific constraint of each field position. Discrepancies between some mass and height developments question the (disproportionate) large mass increase (relative to the height increase) during the 1980s and 1990s.

International audience; It has recently been demonstrated that in healthy individuals, peak oxygen consumption is associated with a greater pulmonary capillary blood volume and a more distensible pulmonary circulation. Our cross-sectional study suggests that, in healthy men aged 20 to 60 years (n = 63), endurance sport practice (vigorous-intensity domain of the International Physical Activity Questionnaire) is associated with better quantity (pulmonary capillary blood volume) and quality (slope of increase in lung diffusion for carbon monoxide on exercise) of the pulmonary vascular bed, partly counterbalancing the deleterious effects of ageing, which remains to be demonstrated in a prospective longitudinal design.

International audience; The purpose of this study is to investigate the association between anthropometric characteristics and performance in all track and field running events and assess Body Mass Index (BMI) as a relevant performance indicator. Data of mass, height, BMI and speed were collected for the top 100 international men athletes in track events from 100 m to marathon for the 1996–2011 seasons, and analyzed by decile of performance. Speed is significantly associated with mass (r = 0.71) and BMI (r = 0.71) in world-class runners and moderately with height (r = 0.39). Athletes, on average were continuously lighter and smaller with distance increments. In track and field, speed continuously increases with BMI. In each event, performances are organized through physique gradients. «Lighter and smaller is better» in endurance events but «heavier and taller is better» for sprints. When performance increases, BMI variability progressively tightens, but it is always centered around a distance-specific optimum. Running speed is organized through biometric gradients, which both drives and are driven by performance optimization. The highest performance level is associated with narrower biometric intervals. Through BMI indicators, diversity is possible for sprints whereas for long distance events, there is a more restrictive aspect in terms of physique. BMI is a relevant indicator, which allows for a clear differentiation of athletes' capacities between each discipline and level of performance in the fields of human possibilities.

International audience; Purpose: The purpose of this study is to examine whether performance supercompensation during taper is maximized in endurance athletes after experiencing overreaching during an overload training (OT) period. Methods: Thirty-three trained male triathletes were assigned to either OT (n = 23) or normal training groups (n = 10, CTL) during 8 wk. Cycling performance and maximal oxygen uptake (V ˙ O 2max) were measured after 1 wk of moderate training, a 3-wk period of OT, and then each week during 4-wk taper. Results: Eleven of the 23 subjects from the OT group were diagnosed as functionally overreached (FOR) after the overload period (decreased performance with concomitant high perceived fatigue), whereas the 12 other subjects were only acutely fatigued (AF) (no decrease in performance). According to qualitative statistical analysis, the AF group demonstrated a small to large greater peak performance supercompensation than the FOR group (2.6% T 1.1%) and the CTL group (2.6% T 1.6%). V ˙ O 2max increased significantly from baseline at peak performance only in the CTL and AF groups. Of the peak performances, 60%, 83%, and 73% occurred within the two first weeks of taper in CTL, AF, and OR, respectively. Ten cases of infection were reported during the study with higher prevalence in FOR (70%) than that in AF (20%) and CTL (10%). Conclusion: This study showed that 1) greater gains in performance and V ˙ O 2max can be achieved when higher training load is prescribed before the taper but not in the presence of FOR ; 2) peak performance is not delayed during taper when heavy training loads are completed immediately prior; and 3) FOR provides higher risk for training maladaptation, including increased infection risks. T he primary goal for coaches of high-performance athletes is to deliver a well-controlled training program to ensure that the maximal performance is achieved at major competitions. The best competition performances in endurance sports are often achieved after a taper phase, which is typically completed after periods of heavy training. The taper has been defined as a progressive, nonlinear reduction of the training load in the period before competition (19). The main purpose of the taper is to reduce physiological and psychological stressors of previous training and to remove residual fatigue so that sport performance can be optimized. Appropriate tapering is considered to be critical for maximizing athletic performance. However, at present, there is relatively little scientific information that can be used to guide coaches in prescribing appropriate tapering strategies for individual athletes, and as a result, many adopt a trial-and-error approach. Indeed, only recently has good empirical evidence been provided to allow us to understand the relations between the characteristics of endurance training during a taper and the associated endurance performance changes (2,16). For example, Bosquet et al. (3) used a meta-analytic analysis to describe the effects of alterations in the training characteristics during the taper on performance in competitive athletes. The results showed that the most efficient taper strategy for maximizing endurance performance gains was to perform a 2-wk taper with an exponential reduction in training volume by 41%–60% without any modification of either training intensity or frequency. Using mathematical modeling simulations, Thomas and Busso (21) demonstrated that the training leading into the taper may also influence the performance responses during taper (21). These stimulations predicted that a 20% increase in training beyond normal training load during 28 d before a taper would elicit larger performance gains compared with when habitual training load was maintained. This hypothesis was recently supported by Le Meur et al. (16), who compared performance supercompensation after a 1-wk taper in trained triathletes after 3 wk of training, which consisted of either overload or habitual training. At the end of the overload training (OT) period, a 9% decline in performance

The thesis deals with the epidemiology and physiopathology of performance in elite sport.The objective is to analyze the impact of two parameters that can affect performance and itsdevelopment during a sports career: injury and environmental factors.At first, we study the impact of the Anterior Cruciate Ligament (ACL) rupture on the performance ofthe best alpine skiers (1st decile of performance) in the French Team since 1980. Through atransversal study, we analyze the return to performance after an ACL injury and evaluate whetherthe injury is a handicap in post-rupture performance. It is also an opportunity to demonstrate andcompare the performance of the best skiers who had a torn ACL with those who never suffered thisinjury during their career. Secondly, a second longitudinal study analyses the performancedevelopment of the entire alpine skiers in the French Team during their career in injured and noninjuredathletes since 1980.Moreover, in alpine skiing the environment plays a role in the occurrence of injuries. The snowconditions, weather conditions and temperature are all factors that influence the prevalence ofinjuries, including the ACL rupture. Thus, in a third study we evaluated the impact of seasonality andenvironment in the sprint and middle distance. This study was conducted in athletics because itrepresents one of the oldest Olympic sports with sufficient data available allowing a substantialhistorical perspective of performance.Our studies describe the importance of taking into account the injury and the environment,particularly temperature, in the multifactorial context of performance optimization in elite sport., La thèse porte sur l’épidémiologie et la physiopathologie de la performance dans le sport dehaut niveau (SHN). L’objectif principal est d’étudier l’impact de deux paramètres pouvant interféreravec les performances et leur développement au cours d’une carrière sportive : la blessure et lesfacteurs environnementaux.Dans un premier temps, nous étudions l’impact de la rupture du Ligament Croisé Antérieur (LCA) surles performances chez les meilleurs skieurs alpins en Equipe de France depuis 1980. A travers uneétude transversale, nous analysons le retour à la performance après la rupture du LCA chez lesskieurs et évaluons si cette blessure est un handicap en termes de performances post-rupture dans leski alpin de compétition. Elle est aussi l’occasion de comparer les performances des meilleurs skieursde l’équipe qui ont connu la rupture du LCA avec celles des skieurs qui n’ont jamais subi cetteblessure au cours de leur carrière. Une deuxième étude longitudinale compare l’évolution desperformances de l’ensemble de la population de l’Equipe de France en ski alpin sur les carrièrescomplètes des athlètes avec rupture du LCA et des athlètes sans rupture depuis 1980.En ski alpin, l’environnement est étroitement impliqué dans la survenue des blessures. Les conditionsde la neige, les conditions météorologiques et la température sont des facteurs qui influencent laprévalence des blessures, notamment celles du genou. L’environnement et les contraintes qu’il exigevont aussi influencer la performance dans le SHN. Ainsi, dans une troisième étude nous avons évaluél’impact de la saisonnalité et de l’environnement dans les épreuves de sprint et de demi-fond. Cetteétude est réalisée en athlétisme car il représente l’un des premiers sports olympiques avec uneaccessibilité des données permettant un recul historique des performances considérable.La blessure et l’environnement sont deux paramètres indispensables à prendre en compte dans lecadre multifactoriel de l’optimisation de la performance dans le SHN.

International audience; This study was undertaken to examine the effect of different pedalling cadences upon various physiological responses during endurance cycling exercise. Eight well-trained triathletes cycled three times for 30 min each at an intensity corresponding to 80% of their maximal aerobic power output. The first test was performed at a freely chosen cadence (FCC); two others at FCC-20% and FCC +20%, which corresponded approximately to the range of cadences habitually used by road racing cyclists. The mean (SD) FCC, FCC-20% and FCC + 20% were equal to 86 (4), 69 (3) and 103 (5) rpm respectively. Heart rate (HR), oxygen uptake (VO2), minute ventilation (VE) and respiratory exchange ratio (R) were analysed during three periods: between the 4th and 5th, 14th and 15th, and 29th and 30th min. A significant effect of time (P < 0.01) was found at the three cadences for HR, VO 2. The V E and R were significantly (P < 0.05) greater at FCC + 20% compared to FCC-20% at the 5th and 15th min but not at the 30th min. Nevertheless, no significant effect of cadence was observed in HR and VO 2. These results suggest that, during high intensity exercise such as that encountered during a time-trial race, well-trained triathletes can easily adapt to the changes in cadence allowed by the classical gear ratios used in practice.

International audience; Whether exertional dyspnoea can be attributed to poor circulatory-muscular conditioning is a difficult clinical issue. Because criteria of poor conditioning such as low oxygen pulse, low ventilatory threshold or high heart rate/oxygen consumption slope can be observed in heart or lung diseases and are not specific to conditioning, we assessed the relationships between physical exercise, conditioning and exertional breathlessness in healthy subjects, in whom the aforementioned criteria can confidently be interpreted as reflecting conditioning. To this end, healthy males with either low (inactive men, n = 31) or high (endurance-trained men, n = 31) physical activity evaluated using the International Physical Activity Questionnaire (IPAQ) underwent spirometry and incremental exercise testing with breathlessness assessment using Borg scale. No significant breathlessness was reported before the ventilatory threshold in the two groups. Peak breathlessness was highly variable, did not differ between the two groups, was not related to any conditioning criterion, but correlated with peak respiratory rate. Nevertheless, endurance-trained subjects reported lower breathlessness at the same ventilation levels in comparison with inactive subjects. Significant but weak associations were observed between isoventilation breathlessness and physical activity indices (Borg at 60 L/min and total IPAQ scores, rho = -0.31, p = 0.020), which were mainly attributable to the vigorous domain of physical activity, as well as with conditioning indices (Borg score at 60 L.min(-1) and peak oxygen pulse or heart rate/oxygen consumption slope, rho = -0.31, p = 0.021 and rho = 0.31, p = 0.020; respectively). In conclusion, our data support a weak relationship between exertional breathlessness and circulatory-muscular conditioning, the later being primarily related to vigorous physical activity.

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., L’objectif de cette thèse est d’étudier les évolutions morphologiques des sportifs de haut niveau (SHN) 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. Dansl’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 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.; 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.

Animal movement has been identified as a key feature in understanding animal behavior, distribution and habitat use and foraging strategies among others. Large datasets of invididual locations often remain unused or used only in part due to the lack of practical models that can directly infer the desired features from raw GPS locations and the complexity of existing approaches. Some of them being disputed for their lack of biological justifications in their design. We propose a simple model of individual movement with explicit parameters, based on a two-dimensional biased and correlated random walk with three forces related to advection (correlation), attraction (bias) and immobility of the animal. These forces can be directly estimated using individual data. We demonstrate the approach by using GPS data of 5 red deer with a high frequency sampling. The results show that a simple random walk template can account for the spatial complexity of wild animals. The practical design of the model is also verified for detecting spatial feature abnormalities and for providing estimates of density and abundance of wild animals. Integrating even more additional features of animal movement, such as individuals’ interactions or environmental repellents, could help to better understand the spatial behavior of wild animals.

International audience; Introduction:Marker-based kinematics is hardly compatible with sports movement analysis, especially because it hinders natural movement. Hence, deep-learning based markerless solutions are being developed, such as Pose2Sim [1]. Sports in competition may also be subject to setup constraints, preventing the use of heavy equipment and installation. The use of lightweight action cameras, with post-calibration and post-synchronization, can be pertinent in this context. This study aimed at investigating the accuracy of the Pose2Sim pipeline in such suboptimal conditions. We assessed the measures of key performance indicators in boxing, which involves swift and 3-dimensional full-body movements.Methods:One male elite boxer performed 6 repetitions of a boxing sequence composed of 3 punches (jab, high hook, low hook). His 3D motion was captured both with a marker-based protocol, and with a light-weight markerless one. The latter involved 8 GoPro cameras, which were post-calibrated based on the dimensions of the boxing ring, and post-synchronized based on time-lagged correlations of 2D keypoints speeds between paired cameras. The markerless kinematic analysis was then performed with Pose2Sim. Both protocols used the same OpenSim [2] model to optimize inverse kinematics. Displacement of lead foot, pelvis, lead fist, and velocity of lead fist were analyzed for the jab. Rotation of rear foot, pelvis, displacement of rear fist, and velocity of rear fist were analyzed for the hooks. Waveform similarity was assessed with the inter-protocol coefficient of multiple correlation [3]. Time and magnitude of peaks were also compared.Results:Results from the marker-based and markerless approaches demonstrated excellent waveform similarity (CMC>0.94), and times-to-peak exhibited intervals of under one frame (i.e., 17 ms). Magnitudes-at-peak were very close for displacements (below 6 cm), but not for fist velocity on jab (1.2m/s difference) nor for rotations on hooks (up to 20° difference, e.g. for pelvis rotation).Conclusion:Despite the use of action cameras, and of suboptimal calibration and synchronization procedures, our lightweight markerless protocol gives satisfying results for the analysis of key performance indicators in boxing, especially for limb displacements. Nevertheless, results should be taken with caution for velocity and for rotation measurements. Such a light-weight markerless protocol could be useful in situations where more accurate marker-based approaches are not conceivable, such as sports competitions.

3D-AHM 2022, 17th International Symposium of 3-D Analysis of Human Movement, Tokyo, JAPON, 16-/07/2022 - 19/07/2022; This work aims to compare markerless joint kinematics of the upper extremity processed with Theia3D with respect to those measured by marker-based method during in-the-field shadow boxing.

International audience; Purpose: Achievement of athletes' performances is related to several factors including physiological, environmental and institutional cycles where physical characteristics are involved. The objective of this study is to analyse the performance achieved in professional sprint and middle-distance running events (100 m to 1500 m) depending on the organization of the annual calendar of track events and their environmental conditions.Methods: From 2002 to 2008, all performances of the Top 50 international athletes in the 100 m to 1500 m races (men and women) are collected. The historical series of world records and the 10 best annual performances in these events, amounted to a total of 26,544 performances, are also included in the study.Results: Two periods with a higher frequency of peak performances are observed. The first peak occurs around the 27.15 th 60.21 week (first week of July) and the second peak around 34.75 th 60.14 week (fourth week of August). The second peak tends to be the time of major international competitions (Olympic Games, World Championships, and European Championships) and could be characterized as an institutional moment. The first one, however, corresponds to an environmental optimum as measured by the narrowing of the temperature range at the highest performance around 23.2563.26uC.Conclusions: This is the first study to demonstrate that there are two performance peaks at a specific time of year (27th and 34th weeks) in sprint and middle distance. Both institutional and ecophysiological aspects contribute to performance in the 100 m to 1500 m best performances and define the contours of human possibilities. Sport institutions may take this into account in order to provide ideal conditions to improve the next records.

International audience; Purpose: The aim of this study was to evaluate concomitantly the changes in leg-spring behavior and the associated modifications in the lower limb muscular activity during a constant pace run to exhaustion at severe intensity. Methods: Twelve trained runners performed a running test at the velocity associated with _ VO 2max (5.1 70.3 m s −1 ; mean time to exhaustion: 3537 69 s). Running step spatiotemporal parameters and spring-mass stiffness were calculated from vertical and horizontal components of ground reaction force measured by a 6.60 m long force platform system. The myoelectrical activity was measured by wireless surface electrodes on eight lower limb muscles. Results: The leg stiffness decreased significantly (−8.9%; Po 0.05) while the vertical stiffness did not change along the exhaustive exercise. Peak vertical force (−3.5%; Po 0.001) and aerial time (−9.7%; P o0.001) decreased and contact time significantly increased (+4.6%; Po 0.05). The myoelectrical activity decreased significantly for triceps surae but neither vastus medialis nor vastus lateralis presented significant change. Both rectus and biceps femoris increased in the early phase of swing (+14.7%; P o0.05) and during the pre-activation phase (+16.2%; Po 0.05). Conclusion: The decrease in leg spring-stiffness associated with the decrease in peak vertical ground reaction force was consistent with the decline in plantarflexor activity. The biarticular rectus femoris and biceps femoris seem to play a major role in the mechanical and spatiotemporal adjustments of stride pattern with the occurrence of fatigue during such exhaustive run.

National audience; «!Le désir de maintenir le cours naturel des choses jusqu’à ce qu’il soit trop tard, est la plus grande menace que l’humanité fait peser sur elle-même!», écrivait André Lebeau dans l’un de ses derniers ou -vrages, L’Enfermement planétaire (Paris!: Gallimard, 2008). Car en effet, la confrontation de l’humanité aux limites de l’écosystème terrestre pourrait bien mener celle-ci sinon à sa perte, du moins à de trèsbrutales révisions de ses modes de vie et de consommation. C’est aussi le constat dressé dans cet article!: course à la performance, transitions (démographique, nutritionnelle, agricole, épidémiologique…)touchant la plupart des pays, conséquences environnementales des changements de modes de vie observés depuis la révolution industrielle, qui s’accélèrent au fil du temps tout en essaimant sur tous les continents…, tout concourt à indiquer que l’espèce humaine approche d’un tournant. Divers plafonnements sont observés !: dans la consommation d’énergie, dans les performances sportives, économiques, dans l’augmentation de l’espérance de vie…!; plafonnements qui ne pourraient être repoussés (pour tenter de suivre les courbes passées), qu’aux dépens des écosystèmes ou des générations futures. Un tel scénario serait inacceptable compte tenu des pressions déjà observées sur l’environnement!; le défi est donc bien, selon les auteurs, de réconcilier l’homme avec son environnement, en «!défini[ssant] le superflu et situ[ant] l’acceptable!», à l’échelle mondiale et de manière concertée. Ne pouvant plus s’«!illusionner de progrès infinis!», sauf à risquer le scénario du pire et une rupture violente, l’humanité doit désormais revoir, collectivement, son mode de développement pour espérer durer. (S.D.)

International audience; Aim. The aim of this paper was to investigate the changes over time in anthropometric parameters of young and adult rugby players in France. Methods. Age, mass and height were collected for 2051 French elite rugby players participating in the championship during the 1988-1989 and the 2008-2009 seasons. The same variables were collected for the best 145 juniors (under 21 years) and 448 U15 (under 15 years) French players for these seasons. Changes in anthropometric parameters were compared according to age, category (back vs. forwards) and season. Results. Over 20 years, adult French rugby backs and forwards have become heavier by 12 kg and 12.3 kg, taller by 5.4 cm and 2.9 cm, respectively. Junior players also became taller and heavier, 6 cm and 9.9 kg for backs and 4.4 cm and 11.1 kg for forwards. U15 backs have gained 5.1 cm and 6.5 kg, and forwards earned 4.7 cm and 4.7 kg. Conclusion. Rugby players have become taller and heavier. Their current morphology is the product of a long process of competition and selection. This study demonstrates that this selection of the " large sizes " is already present at a young age.

National audience; Les tentatives d’amélioration singulière des capacités humaines ont toujours existé et les produits augmentant les performances ont, de tout temps, fait la fortune d’apprentis sorciers qui tiraient parti de la crédulité des simples… Dès les jeux antiques, où seule comptait la victoire, les philtres et autres élixirs furent monnaie aussi courante que la corruption des édiles ou les courses arrangées. En parallèle, la lutte contre ces pratiques, qui commence dès l’antiquité avec les recours adressés aux organisateurs, s’est adaptée et s’intensifie constamment. Mais peut-on également employer d’autres outils, plus inattendus ?

International audience; This study investigated the effect of whole-body cryostimulation (WBC), contrast-water therapy (CWT), active recovery (ACT), and passive condition (PAS) protocols on the parasympathetic reactivation and metabolic parameters of recovery in elite synchronized swimmers who performed 2 simulated competition ballets (B1 and B2) separated by 70 min. After determining maximal oxygen consumption (V ˙ O 2max400) and blood lactate concentrations ([La − ] b400) during a 400-m swim trial, 11 swimmers performed 1 protocol per week in randomized order. Heart rate variability (HRV) was measured at rest (PreB1), 5 min after B1 (PostB1), before B2 (PreB2), and 5 min after B2 (PostB2). V ˙ O 2peak was measured at PostB1 and PostB2, and [La − ] b was measured at PostB1, PreB2, and PostB2. PostB1 V ˙ O 2peak and V ˙ O 2max400 were similar, but PostB1 [La − ] b was higher than [La − ] b400 (p = 0.004). Each ballet caused significant decreases in HRV indices. At PreB2, all HRV indices had returned to PreB1 levels in the CWT, PAS, and ACT protocols, whereas the WBC protocol yielded a 2-to 4-fold increase in vagal-related HRV indices, compared with PreB1. WBC and ACT both increased [La − ] b recovery, compared with PAS (p = 0.06 and p = 0.04, respectively), and yielded an increased V ˙ O 2peak from B1 to B2; however, it decreased after PAS (+5.4%, +3.4%, and −3.6%; p < 0.01). This study describes the physiological response to repeated maximal work bouts that are highly specific to elite synchronized swimming. In the context of short-term recovery, WBC yields a strong parasympathetic reactivation, and shows similar effectiveness to ACT on the metabolic parameters of recovery and subsequent exercise capacity. Résumé : Cette étude analyse l'effet de la cryostimulation de l'organisme en entier (« WBC »), de la thérapie par contraste de température (« CWT »), des protocoles actifs (ACT) et passifs (PAS) sur la réactivation sympathique et les paramètres métaboliques de la récupération chez des nageuses synchronisées de niveau élite réalisant deux chorégraphies (B1 et B2) en compétition simulée a ` 70 min d'intervalle. Après l'évaluation de la consommation maximale d'oxygène (V ˙ O 2max400) et de la concentration sanguine de lactate ([La − ] b400) au cours d'une épreuve de 400 m a ` la nage, 11 nageuses participent de façon aléatoire a ` toutes les conditions expérimentales a ` raison d'une par semaine. On évalue la variabilité du rythme cardiaque (HRV) au repos (PreB1), 5 min après B1 (PostB1), avant B2 (PreB2) et 5 min après B2 (PostB2). On évalue le V ˙ O 2 de pointe a ` PostB1 et a ` PostB2 de même que la [La − ]b a ` PostB1, PreB2 et PostB2. À PostB1, le V ˙ O 2 de pointe est similaire au V ˙ O 2max400 , mais la [La − ]b est supérieure a ` [La − ] b400 (p = 0,004). Chaque chorégraphie suscite une diminution significative des indices de HRV. À PreB2 dans les conditions CWT, PAS et ACT, tous les indices de HRV présentent des valeurs observées a ` PreB1, mais dans la condition WBC, on observe 2 a ` 4 fois plus d'augmentation de la valeur des indices HRV associés aux fonctions vagales, comparativement a ` PreB1. Dans les conditions WBC et ACT, on observe une augmentation de la [La − ] b de récupération comparativement a ` la condition PAS (p = 0,06 et p = 0,04); de plus, dans les conditions WBC et ACT, on observe une augmentation du V ˙ O 2 de pointe de B1 a ` B2, lequel diminue après PAS (+5,4%, +3,4% et −3,6%, p < 0,01). Cette étude décrit des ajustements physiologiques a ` des séances répétées d'exercice maximal spécifique a ` la natation synchronisée de niveau élite. Dans un contexte de récupération brève, WBC révèle une importante réactivation parasympathique et s'avère aussi efficace qu'ACT dans la récupération des variables métaboliques et de la capacité physique subséquente. [Traduit par la Rédaction] Mots-clés : cryothérapie globale, athlète féminine, variabilité du rythme cardiaque, exercice maximal, immersion dans l'eau, récupération active.

International audience; PURPOSE: To evaluate spring-mass (SM) behavior and associated electromyographic (EMG) activity during a run to exhaustion following a cycle exercise in trained triathletes. METHODS: Ten triathletes completed four tests: a cycling test to determine V˙O(2max); a running test to determine the lactate threshold (LT); a 5 min control run at LT (C-Run) followed after a total recovery period by a cycle-to-run session to exhaustion [30 min of cycling at ∼80% V˙O(2max) followed by a run until exhaustion at LT (T-Run)]. SM behavior and EMG signals in nine lower limb muscles were recorded throughout the running sessions. RESULTS: Immediately after cycling, leg stiffness was 12.1% higher than its C-Run value and a concomitant increase of EMG activity of knee extensors was observed during pre-contact. Throughout T-Run, leg stiffness decreased by 7.3%, while knee extensors and ankle flexors activities decreased during pre-contact and braking phases. No significant variations in SM parameters and no significant increase of muscle activity were reported between C-Run and the end of T-Run. CONCLUSION: SM behavior during the cycle-run test was consistent with EMG activity changes. Cessation of exercise was not associated with significant alterations of stiffness values and EMG activity.

Background/Objective: This study aimed to investigate the effects of regular hot water bathing (HWB), undertaken 10 min after the last training session of the day, on chronic adaptations to training in elite athletes. Methods: Six short-track (ST) speed skaters completed four weeks of post-training HWB and four weeks of post-training passive recovery (PR) according to a randomized cross-over study. During HWB, participants sat in a jacuzzi (40 °C; 20 min). Results: According to linear mixed models, maximal isometric strength of knee extensor muscles was significantly increased for training with HWB (p 0.05), including aerobic peak power output, the decline rate of jump height during 1 min-continuous maximal countermovement jumps (i.e. anaerobic capacity index), and the force-velocity relationship. Regarding specific tasks on ice, a small effect of training was found on both half-lap time and total time during a 1.5-lap all-out exercise (p = 0.0487; d = 0.23 and p = 0.0332; d = 0.21, respectively) but no additional effect of HWB was observed. Conclusion: In summary, the regular HWB protocol used in this study can induce additional effects on maximal isometric strength without compromising aerobic and anaerobic adaptations or field performance in these athletes.

International audience; Locomotion is one of the major physiological functions for most animals. Previous studies have described aging mechanisms linked to locomotor performance among different species. However, the precise dynamics of these age-related changes, and their interactions with development and senescence, are largely unknown. Here, we use the same conceptual framework to describe locomotor performances in Caenorhabditis elegans, Mus domesticus, Canis familiaris, Equus caballus, and Homo sapiens. We show that locomotion is a consistent biomarker of age-related changes, with an asymmetrical pattern throughout life, regardless of the type of effort or its duration. However, there is variation (i) among species for the same mode of locomotion, (ii) within species for different modes of locomotion, and (iii) among individuals of the same species for the same mode of locomotion. Age-related patterns are modulated by genetic (such as selective breeding) as well as environmental conditions (such as temperature). However, in all cases, the intersection of the rising developmental phase and the declining senescent phase reveals neither a sharp transition nor a plateau, but a smooth transition, emphasizing a crucial moment: the age at peak performance. This transition may define a specific target for future investigations on the dynamics of such biological interactions.

International audience; Running speed in animals depends on both genetic and environmental conditions. Maximal speeds were here analysed in horses, dogs and humans using data sets on the 10 best performers covering more than a century of races. This includes a variety of distances in humans (200–1500 m). Speed has been progressing fast in the three species, and this has been followed by a plateau. Based on a Gompertz model, the current best performances reach 97.4% of maximal velocity in greyhounds to 100.3 in humans. Further analysis based on a subset of individuals and using an ‘animal model’ shows that running speed is heritable in horses (h2 = 0.438, P = 0.01) and almost so in dogs (h2 = 0.183, P = 0.08), suggesting the involvement of genetic factors. Speed progression in humans is more likely due to an enlarged population of runners, associated with improved training practices. The analysis of a data subset (40 last years in 800 and 1500 m) further showed that East Africans have strikingly improved their speed, now reaching the upper part of the human distribution, whereas that of Nordic runners stagnated in the 800 m and even declined in the 1500 m. Although speed progression in dogs and horses on one side and humans on the other has not been affected by the same genetic/environmental balance of forces, it is likely that further progress will be extremely limited.

International audience; The purpose of this study is to compare training load quantification methods " Work-Endurance-Recovery " , " session-CR10 " and " Training impulse " during a period of post-injury physical rehabilitation in professional soccer players. Methods: Eleven young soccer players injured participated in the study. This period of physical rehabilitation is composed of sessions of muscle conditioning, proprioception and individual work with ball. For all training sessions, Work-Endurance-Recovery training loads are not related to session-CR10 (P = 0.11). These two types of training loads result in significant correlations for proprioception and ball sessions (R 2 = 0.60). In addition, significant correlation coefficients appear between TRIMPs and WER training loads (R 2 = 0.62), and between TRIMPs (only calculated for proprioception and ball sessions) and session-CR10 (R 2 = 0.66). Quantification of muscle conditioning sessions differs between Work-Endurance-Recovery and session-CR10 methods. These differences are due to the fact that the increase in exercise intensity associated with unchanged volume results in decreased effort perception. The particular context of muscular conditioning after injury underlines the limits of session-CR10 quantification method used during the first phase of a physical rehabilitation period. The WER method seems useable for all phases of physical rehabilitation. Our study underlines the feasibility of training load quantification for physical rehabilitation exercises after injuries that could allow to improve such exercises programs.; L'objectif de notre travail a été de comparer les méthodes de quantification de la charge d'entraînement « Travail-Endurance-Récupération », « séance-CR10 » et Training impulse lors d'une période de réhabilitation athlétique chez le footballeur professionnel. Sujets et méthodes : onze jeunes footballeurs (16,0 ± 1,2 ans) blessés parmi les 90 jeunes footballeurs fréquentant le Centre technique national Clairefontaine de la Fédération française de football ont fait l'objet d'un recueil de données au cours de leur réhabilitation athlétique post-blessure. Cette période de réhabilitation comprend des séances de renforcement musculaire, de travail des appuis puis de travail individuel avec ballon. Résultats : Pour l'ensemble des séances, les charges Travail-Endurance-Récupération ne sont pas reliées aux charges séance-CR10 (p = 0,11). Pour les séances d'appui et avec ballon, des relations significatives apparaissent entre les charges Travail-Endurance-Récupération et séance-CR10 (R 2 = 0,60), entre Travail-Endurance-Récupération et Training impulse (R 2 = 0,62) et entre séance-CR10 et Training impulse (R 2 = 0,66). L'évolution des charges des séances de renforcement diffère entre les méthodes Travail-Endurance-Récupération et séance-CR10. Ces différences résident dans le fait que l'augmentation de l'intensité de travail à volume constant se traduit par une baisse de la perception de l'effort. Les conditions très particulières du renforcement musculaire post-blessure font apparaître des limites quant à l'utilisation de la méthode séance-CR10 lors de la première phase de réhabilitation. La méthode Travail-Endurance-Récupération semble utilisable pour l'ensemble des phases de travail. Conclusion : Notre étude souligne la faisabilité de la quantification de la charge d'entraînement des périodes de réhabilitation athlétique post-blessure ce qui devrait permettre d'optimiser les programmes proposés.

International audience; Objective: To analyze the physical fitness level of 31 133 French citizens aged between 8 and 60 years old and represent the performances through a bi-exponential model.Methods: We collected data from 231 events that took place in French regions between 2006 and 2010 and analyzed participation and physical fitness using a simple series of tests. We assessed outcome measures in relation to age and BMI using Spearman Rho, a one way ANOVA and a bi-exponential model.Results: Our major results showed higher performances for men and for subjects with normal BMI at all age groups except for the flexibility test. Body mass index is strongly correlated across all ages with physical fitness p < 0.0001. Those results are in accordance with the literature. Furthermore, through a biexponential model, a mean peak performance was identified at 26.32 years old for men and 22.18 years old for women.Conclusion: Physical fitness assessment using simple tests is applicable on the general population and is correlated to age, BMI and health status. The application of a bi-exponential model offers a global approach to monitor public health.

Cette étude porte sur les phénomènes de compréhension conjointe des situationsentre l’entraîneur et l’athlète. La compréhension était envisagée à partir de la compatibilité(i.e., points communs) des informations rapportées par chacun, lorsqu’il décrivait l’activitéqu’il avaient eue en compétition et à l’entraînement post-compétition. L’étude visait àcaractériser : (a) les informations compatibles entre l’entraîneur et l’athlète à chaque instant, et(b) leurs modes de compatibilité. Trois lanceurs de marteau de haut niveau et leur entraîneuront participé à l’étude. Une compétition estivale et l’entraînement post-compétition ont étéenregistrés pour chaque athlète et son entraîneur. Un entretien en auto-confrontation a étémené séparément avec chaque participant en relation avec la compétition et l’entraînementpost-compétition. Les résultats ont montré que les informations compatibles renvoyaient àcinq catégories d’éléments : (a) les éléments techniques du jet ; (b) les états psychologiques del’athlète ; (c) l’organisation et la sécurité de la pratique ; (d) la performance ; et (e) l’expériencepartagée avec l’athlète. Les résultats ont également montré trois modes de compatibilité desinformations : (a) non compatible ; (b) compatible ; et (c) mutuellement compatible (i.e.,l’entraîneur et l’athlète ont conscience qu’elles sont compatibles). Les résultats suggèrentque l’entraîneur et l’athlète ont une compréhension conjointe des situations basée surl’apprentissage d’habiletés, l’évolution de la situation en cours et le contexte de la pratique. Ilssuggèrent une communication asymétrique entre l’entraîneur et l’athlète. Des perspectivessont proposées pour améliorer la communication entre l’entraîneur et l’athlète et favoriserleur compréhension conjointe des situations.

International audience

International audience; Purpose: The objectives of this study were to describe the distribution of all runners' performances in the largest marathons worldwide and to determine which environmental parameters have the maximal impact. Methods: We analysed the results of six European (Paris, London, Berlin) and American (Boston, Chicago, New York) marathon races from 2001 to 2010 through 1,791,972 participants' performances (all finishers per year and race). Four environmental factors were gathered for each of the 60 races: temperature (uC), humidity (%), dew point (uC), and the atmospheric pressure at sea level (hPA); as well as the concentrations of four atmospheric pollutants: NO 2 – SO 2 – O 3 and PM 10 (mg.m 23). Results: All performances per year and race are normally distributed with distribution parameters (mean and standard deviation) that differ according to environmental factors. Air temperature and performance are significantly correlated through a quadratic model. The optimal temperatures for maximal mean speed of all runners vary depending on the performance level. When temperature increases above these optima, running speed decreases and withdrawal rates increase. Ozone also impacts performance but its effect might be linked to temperature. The other environmental parameters do not have any significant impact. Conclusions: The large amount of data analyzed and the model developed in this study highlight the major influence of air temperature above all other climatic parameter on human running capacity and adaptation to race conditions.

International audience

National audience

L’objet de ce projet était d’examiner l’influence de l’environnement visuel sur lesactivités électro-corticales lors de tâches de mémorisation de mouvements sportifs.Douze sportifs experts pratiquant des activités de productions de formes (i.e.,activités morphocinétiques) ont été invités à retenir des séquences de gestes sportifsqu’ils devaient reconnaître ultérieurement. Ces séquences étaient enchâsséesdans des environnements différents : un environnement habituel, écologique(vidéo «classique») et un environnement inhabituel, minimaliste i.e. appauvri eninformations visuelles (vidéo animée de points lumineux). L’activité cérébrale a étéenregistrée à partir de 64 électrodes. Cinq bandes de fréquence (4-8 Hz, 8-10 Hz,10-13 Hz, 13-20 Hz, et 20-30 Hz) ont été considérées. Une mesure de connectivitéfonctionnelle, l’indice de décalage de phase (IDP), a été utilisée. Les résultats ontmontré que, dans la bande de fréquence 13-20 Hz, la connectivité fonctionnelleétait plus importante au sein des zones frontale et temporale droite lors de lamémorisation de séquences animées de points lumineux que lors de séquencesde vidéos «classiques.» Les données ont également mis en évidence que les sujetsemployaient les mêmes stratégies pour retenir ces séquences et ceci quelque soit lecontexte considéré. Les résultats ont été discutés en relation avec les travaux récentsréalisés dans le domaine des neurosciences cognitives et plus particulièrement dela littérature sur la mémoire de travail. Des applications pratiques ont été suggérées.

Cette étude porte sur les phénomènes de compréhension conjointe des situationsentre l’entraîneur et l’athlète. La compréhension était envisagée à partir de la compatibilité(i.e., points communs) des informations rapportées par chacun, lorsqu’il décrivait l’activitéqu’il avaient eue en compétition et à l’entraînement post-compétition. L’étude visait àcaractériser : (a) les informations compatibles entre l’entraîneur et l’athlète à chaque instant, et(b) leurs modes de compatibilité. Trois lanceurs de marteau de haut niveau et leur entraîneuront participé à l’étude. Une compétition estivale et l’entraînement post-compétition ont étéenregistrés pour chaque athlète et son entraîneur. Un entretien en auto-confrontation a étémené séparément avec chaque participant en relation avec la compétition et l’entraînementpost-compétition. Les résultats ont montré que les informations compatibles renvoyaient àcinq catégories d’éléments : (a) les éléments techniques du jet ; (b) les états psychologiques del’athlète ; (c) l’organisation et la sécurité de la pratique ; (d) la performance ; et (e) l’expériencepartagée avec l’athlète. Les résultats ont également montré trois modes de compatibilité desinformations : (a) non compatible ; (b) compatible ; et (c) mutuellement compatible (i.e.,l’entraîneur et l’athlète ont conscience qu’elles sont compatibles). Les résultats suggèrentque l’entraîneur et l’athlète ont une compréhension conjointe des situations basée surl’apprentissage d’habiletés, l’évolution de la situation en cours et le contexte de la pratique. Ilssuggèrent une communication asymétrique entre l’entraîneur et l’athlète. Des perspectivessont proposées pour améliorer la communication entre l’entraîneur et l’athlète et favoriserleur compréhension conjointe des situations.

Cette étude a été menée à la demande de M. Bernard LAPORTE, Secrétaire d’Etat aux Sports.Proposée par la LICRA, elle a été confiée au Laboratoire de Sociologie du Sport de l’INSEP.Elle a été réalisée sur la Convention Ministère de la Santé et des Sports/INSEP 023 (janvier 2010-janvier 2012); Le spectacle des terrains de sport ou des équipes de France donne du sport l'image d'une activité où le mérite des individus prime sur leurs origines. Mais la faible représentation de personnes originaires des différentes vagues d'immigration ou des départements d'Outremer parmi les élus ou les cadres techniques donne à penser que le sport, malgré la référence aux valeurs de fraternité, d'égalité ou de mérite, n'échappe pas au phénomène de discrimination. De la même manière, les femmes fortement présentes dans les compétitions de très haut niveau, comme les Jeux Olympiques, ne représentent qu'un peu plus de 10% des cadres ayant en charge l'entraînement ou l'encadrement technique des athlètes des équipes nationales, et ceci même dans les sports à dominante féminine. Nous avons donc cherché à savoir dans ce travail dans quelle mesure l'inégale présence aux différents niveaux du sport (de la pratique à la représentation politique et à l'encadrement technique) des différents groupes composant la société française est l'effet de logiques de discrimination raciale. Plus précisément, nous avons voulu comprendre les raisons et mettre en évidence les mécanismes qui font qu'on peut constater d'un côté qu'en France, la pratique sportive compétitive à tous ses niveaux semble réellement ouverte à tous, sans distinction de classe, de sexe, de nationalité ou de race, et qu'elle est même remarquable par la surreprésentation des minorités dites visibles dans les équipes nationales de certains sports, de l'autre que cette ouverture n'existe plus lorsqu'on s'intéresse aux fonctions sportives techniques ou aux fonctions politiques ou administratives de représentation des différents sports.

Two lactate/proton cotransporter isoforms (monocarboxylate transporters, MCT1 and MCT4) are present in the plasma (sarcolemmal) membranes of skeletal muscle. Both isoforms are symports and are involved in both muscle pH and lactate regulation. Accordingly, sarcolemmal MCT isoform expression may play an important role in exercise performance. Acute exercise alters human MCT content, within the first 24 h from the onset of exercise. The regulation of MCT protein expression is complex after acute exercise, since there is not a simple concordance between changes in mRNA abundance and protein levels. In general, exercise produces greater increases in MCT1 than in MCT4 content. Chronic exercise also affects MCT1 and MCT4 content, regardless of the initial fitness of subjects. On the basis of cross-sectional studies, intensity would appear to be the most important factor regulating exercise-induced changes in MCT content. Regulation of skeletal muscle MCT1 and MCT4 content by a variety of stimuli inducing an elevation of lactate level (exercise, hypoxia, nutrition, metabolic perturbations) has been demonstrated. Dissociation between the regulation of MCT content and lactate transport activity has been reported in a number of studies, and changes in MCT content are more common in response to contractile activity, whereas changes in lactate transport capacity typically occur in response to changes in metabolic pathways. Muscle MCT expression is involved in, but is not the sole determinant of, muscle H+and lactate anion exchange during physical activity.

International audience; Objective: To analyse the physical fitness of a large sample of the French population across different ages. Design: Observational cross-sectional study. Setting: Data were collected from the Athletic Track and Field Federation, which organised events dedicated to measuring physical fitness. The events took place in 22 regions between 2006 and 2010. Participants: French volunteer citizens (N=31 349) aged between 4 and 80 years old who participated in events dedicated to measuring physical fitness. Primary and secondary outcome measures: We assessed the results of the following fitness tests: 20 m shuttle run, standing broad jump, repeated squat jump, 4×10 m shuttle run, speed, flexibility and push-ups in relation to age and body mass index (BMI) using Spearman's rho, a one-way analysis of variance. A bi-exponential model was used to represent the performance with age. Results: Our major results showed higher performances for men and for subjects with normal BMI at all age groups except for the flexibility test. BMI was strongly correlated across all ages with physical fitness p

International audience

The prevalence of sedentary behavior is constantly increasing. Physical inactivity is the 4th causeof preventable death with 1.9 million deaths worldwide. Several studies have proven the needand interest in promoting physical activity in different settings. However, there still exists a largevoid between theory, policies, practice and behavior change.The objective of this thesis is to analyze and develop specific evaluation tools in order toreinforce the proof and utility of recommendations that promote physical activity anddiscourage sedentary behavior.Our first study analyses the data of a physical fitness monitoring tool applied on a large Frenchsample of 31 133 individuals aged between 8 and 60 years old. We first tested the reliability andthe reproducibility of the tool. Thereafter, we analyzed the relation between body mass index,age and the different physiological dimensions measured. Results revealed a goodreproducibility of the physical fitness test and the presence of a strong correlation between theperformances, age and body mass index. This suggests the possibility of using this test as areliable epidemiological tool capable of evaluating the effectiveness of physical activitypromotion interventions.Our second study analyses the effect of an intervention promoting physical activity in theworkplace on subjects suffering from chronic lower back pain. This study has been done incollaboration with the department of occupational medicine in the company. The sampleconsisted of 37 subjects that followed exercise sessions three times per week during twomonths and of 38 subjects in the control group. Physical, psychological, health and socialmeasures were analyzed at three time points (beginning, 2 months, and 6 months). Followingthis intervention, we observed a significant improvement in the physical, psychological andhealth outcome measures that persisted at 6 months. In consequence, this study reinforces thepromotion of physical activity in the workplace in order to assist those at risk and result inmultiple health benefits.Our third study is in relation to the promotion physical activity through active transportation.Our work is related to health impact assessment following a change in transportation mode.This study is in collaboration with the CREAL (Center for Research and EnvironmentalEpidemiology) in Barcelona and six European cities. The study proposes methods to measureenergy expenditure in function of the transportation mode and associates it to a health gain.In conclusion, this thesis offers a new methodological approach as well as specific evaluationtools that may help in advancing the field of prevention by physical activity., La prévalence de la sédentarité ne cesse d’augmenter et de progresser. L’inactivité physique est laquatrième cause de décès évitable: 1.9 millions de décès lui sont attribués dans le monde. Plusieursétudes ont montré l’intérêt et le besoin de promouvoir l’activité physique dans différents milieux.Néanmoins, il reste un grand vide à combler entre la théorie, les politiques et le passage à l’acte.Cette thèse a pour but d’analyser et de développer des outils d’évaluations spécifiques afin d’apporterla preuve de l’utilité des recommandations de promotion d’activité physique et de lutte contre lasédentarité.Notre première étude analyse les données d’un outil de mesure de condition physique en populationgénérale sur un échantillon de 31 133 individus français âgés entre 8 et 60 ans. Nous avons évalué lafiabilité et la reproductibilité de l’outil. Par la suite, nous avons analysé le lien entre l’indice de massecorporelle, l’âge et les performances des différentes dimensions physiologiques mesurées. Les résultatsmontrent une bonne reproductibilité du test et une forte corrélation entre les performances, l’âge etl’indice de masse corporelle. Ceci suggère que l’outil pourrait servir comme instrumentépidémiologique pour évaluer l’efficacité des interventions de promotion d’activité physique.Notre deuxième étude évalue une intervention de remise en forme pour des salariés souffrant dedouleur lombaire chronique en collaboration avec leur service de médecine de travail. Les mesuresd’accompagnement ajustent l’activité physique sur le lieu même de l’entreprise. L’échantillon estconstitué de 37 sujets qui ont suivi des séances d’exercices trois fois par semaine pendant 2 mois et de38 sujets dans le groupe témoin. Les paramètres physiques, psychologiques, sanitaires et sociaux ontété analysés en trois temps (début, 2 mois et 6 mois). Suite à cette intervention, nous avons observéchez le groupe expérimental une amélioration significative des paramètres physiques, psychologiqueset sanitaires, qui persiste à 6 mois. Cette étude renforce donc la promotion d’activité physique enmilieu de travail afin de mieux accompagner les sujets à risques de troubles musculo – squelettiques.Notre troisième étude porte sur les méthodes de promotion d’activité physique à travers les transportsactifs en milieu urbain. Nos travaux sont reliés aux outils d’évaluation d’impact sanitaire suite à unreport modal de transport. Cette étude est réalisée en collaboration avec le CREAL (Center forResearch in Environmental Epidemiology) à Barcelone et six grandes villes européennes. Elle proposedes méthodes de mesure de la dépense énergétique en fonction du mode, associant ces indicateurs àleur gain sanitaire.En conclusion cette thèse fournit une nouvelle méthodologie d’approche ainsi que des outilsd’évaluation spécifiques qui pourront aider à promouvoir la prévention par l’activité physique.

International audience; PURPOSE: To determine whether HR variability (HRV), an indirect measure of autonomic control, is associated with upper respiratory tract and pulmonary infections, muscular affections, and all-type pathologies in elite swimmers. METHODS: For this study, 7 elite international and 11 national swimmers were observed weekly for 2 yr. The indexes of cardiac autonomic regulation in supine and orthostatic position were assessed as explanatory variables by time domain (SD1, SD2) and spectral analyses (high frequency [HF] = 0.15-0.40 Hz, low frequency [LF] = 0.04-0.15 Hz, and HF/LF ratio) of HRV. Logistic mixed models described the relationship between the explanatory variables and the risk of upper respiratory tract and pulmonary infections, muscular affections, and all-type pathologies. RESULTS: The risk of all-type pathologies was higher for national swimmers and in winter (P < 0.01). An increase in the parasympathetic indexes (HF, SD1) in the supine position assessed 1 wk earlier was linked to a higher risk of upper respiratory tract and pulmonary infections (P < 0.05) and to a higher risk of muscular affections (increase in HF, P < 0.05). Multivariate analyses showed (1) a higher all-type pathologies risk in winter and for an increase in the total power of HRV associated with a decline SD1 in supine position, (2) a higher all-type pathologies risk in winter associated with a decline in HF assessed 1 wk earlier in orthostatic position, and (3) a higher risk of muscular affections in winter associated with a decrease SD1 and an increase LF in orthostatic position. CONCLUSIONS: Swimmers' health maintenance requires particular attention when autonomic balance shows a sudden increase in parasympathetic indices in the supine position assessed 1 wk earlier evolving toward sympathetic predominance in supine and orthostatic positions.

International audience; Objectives: Few epidemiological studies have focused on the psychological health of high level athletes. This study aimed to identify the principal psychological problems encountered within French high level athletes, and the variations in their prevalence based on sex and the sport practiced.Methods: Multivariate analyses were conducted on nationwide data obtained from the athletes' yearly psychological evaluations.Results: A representative sample of 13% of the French athlete population was obtained. 17% of athletes have at least one ongoing or recent disorder, generalized anxiety disorder (GAD) being the most prevalent (6%), followed by non-specific eating disorders (4.2%). Overall, 20.2% of women had at least one psychopathology, against 15.1% in men. This female predominance applied to anxiety and eating disorders, depression, sleep problems and self-harming behaviors. The highest rates of GAD appeared in aesthetic sports (16.7% vs. 6.8% in other sports for men and 38.9% vs. 10.3% for women); the lowest prevalence was found in high risk sports athletes (3.0% vs. 3.5%). Eating disorders are most common among women in racing sports (14% vs. 9%), but for men were found mostly in combat sports (7% vs. 4.8%).Discussion: This study highlights important differences in psychopathology between male and female athletes, demonstrating that the many sex-based differences reported in the general population apply to elite athletes. While the prevalence of psychological problems is no higher than in the general population, the variations in psychopathology in different sports suggest that specific constraints could influence the development of some disorders.

The objective of this thesis is to study the evolution of athletic performance during theOlympic era and try to interpret the physiological, technological, genetic and environmentalinfluences.Mathematical modeling of quantifiable sports performance shows similar trends in all events:they follow a piecewise multi-exponential progression punctuated by historical events. Thisglobal vision allows the discovery of a limiting phenomenon common to all disciplines,performance can not continue to grow, and some have already stopped growing. Theselimitations observed in the field of sports are an indicator of physiological limitations of thehuman species.The main factors that would allow for further performance improvements are technologicalinnovations.Furthermore genetic predisposition of athletes and their phenotype resulting from interactionsbetween genes and environment, enable them to perform these maximal athleticperformances. The majority of world records were beaten by athletes from nations that areamong the major world powers, providing a geographical, economic and socio-politicalenvironment promoting the development of sport. Thus we suggest that sport is an indicatorof the secular economical and political development of a country.The results of this thesis analyzing a large number of data provide new insight intoprogression abilities: human physiological performance does not evolve in a linear way., L’objectif de cette thèse est d’étudier l’évolution des performances sportives au cours de l’èreolympique et tenter d’en interpréter les influences physiologiques, technologiques, génétiqueset environnementales.La modélisation mathématique des performances sportives quantifiables montre desévolutions similaires dans toutes les épreuves : elles suivent une loi de progression multiexponentiellepar séries scandée par les événements historiques. Cette vision intégratricepermet la découverte d’un phénomène limitant commun à toutes les disciplines, lesperformances ne peuvent pas continuer à progresser continuellement, certaines ayant déjàcessé de croître. Ces limites observées dans le domaine sportif sont un indicateur des limitesphysiologiques de l’organisme humain.Les principaux facteurs qui permettraient de nouvelles améliorations des performances sontles innovations technologiques.Les prédispositions génétiques des athlètes et leur phénotype qui résulte d’interactions entreleurs gènes et l’environnement leur permettent d’accomplir ces performances sportivesmaximales. La majorité des records du monde a été battue pas les athlètes de nations quicomptent parmi les grandes puissances mondiales, fournissant un environnementgéographique, économique et sociopolitique, favorisant l’épanouissement sportif. Le sport estun indicateur du développement économique et politique d’un pays.Les résultats de cette thèse analysant un nombre important de données apportent une nouvellevision sur nos capacités de progression : les performances physiologiques humaines nes’accroissent pas de manière linéaire.

International audience; One hundred and three athletes participated in a motor task that was ostensibly designed to detect their physical ability (high ego-threatening condition) or provide pretesting data for an upcoming study (low ego-threatening condition) and were then given the opportunity to claim handicaps that could impair their performance on this task. Extending previous findings that high self-handicappers (i.e., athletes who scored high on the self-handicapping scale) and low self-esteem athletes engage in claimed self-handicapping in high ego-threatening conditions, the results reveal that they may also engage in this strategy in low ego-threatening conditions. In the low ego-threatening condition, athletes' self-esteem and self-handicapping tendency explained together 33% of the handicaps they claimed.

La performance dans les activités de locomotion de longue durée est déterminée par de multiples facteurs, parmi lesquels la stratégie d'allure. Ces travaux ont visé à décrire, comprendre et optimiser les variabilités d'allure dans la performance sportivede haut niveau à travers une activité multivariée; le triathlon distance Olympique.La première partie a caractérisé les variabilités d'allure démontrées par des triathlètes «élite» lors d'épreuves internationaleset a différencié celles-ci en fonction du sexe (études nol et no2). Les résultats obtenus ont permis de mieux caractériser lesfacteurs de la performance en triathlon à haut niveau. Ces derniers ont par ailleurs révélé l'adoption d'une stratégie d'alluredécroissante systématique en natation, en cyclisme et en course à pied aussi bien chez les hommes que chez les femmes.Ces études ont aussi mis en évidence une augmentation de la variabilité de la vitesse de locomotion au cours des épreuvesde cyclisme et de course à pied, pour les deux sexes. Si ces stratégies ont semblé cohérentes avec les bénéfices associés àl'adoption d'une position abritée en natation et en cyclisme, l'intérêt d'un départ rapide en course à pied a semblé discutable.Les travaux de la seconde partie ont donc investi gué l'effet de la stratégie d'allure adoptée lors de la phase initiatrice de lacourse à pied sur la performance globale et la réponse physiologique lors d'un triathlon distance Olympique contre-la-montre(étude no3). Les résultats ont démontré que la meilleure stratégie consiste à privilégier sur le premier kilomètre une allure 5%plus lente que celle adoptée en moyenne sur une course de lOkm isolée. La performance globale réalisée est alors en effetmeilleure que celle associée à l'adoption d'une vitesse de course initiale plus élevée. Les résultats ont par ailleurs suggéréque la baisse de vitesse consécutive à un départ rapide est reliée à une diminution de la commande centrale et non à unphénomène de fatigue périphérique. L'étude no4 a confirmé que ces résultats expérimentaux sont transférables à la compétitionà haut niveau en montrant que les meilleurs triathlètes révèlent une vitesse de course moins variable que leurs concurrentsgrâce à un meilleur maintien de celle-ci tout au long de l'épreuve.Dans la continuité de ces travaux, la troisième partie a investigué ce qui engendre l'incapacité des triathlètes à maintenir leurallure de course initiale. L'étude nos a ainsi caractérisé l'évolution simultanée des paramètres cardiorespiratoires,électromyographiques, biomécaniques et perceptuels chez des triathlètes entrainés réalisant un enchaînement cyclisme-courseà pied mené à l'arrêt volontaire. Les résultats ont révélé le maintien des paramètres cardiorespiratoires à des valeurssous-maximales tout au long de l'exercice ainsi qu'une grande stabilité du patron de recrutement musculaire du membreinférieur. Ces données suggèrent que les triathlètes ont stoppé l'exercice, alors qu'ils avaient atteint un niveau maximal dedifficulté d'effort tolérable, sans que la preuve d'une défaillance physiologique puisse être apportée. De prochaines recherchesdevront confirmer cette conclusion et modéliser la manière dont les processus physiologiques, psychologiques et contextuelsinteragissent et déterminent la stratégie d'allure adoptée par les triathlètes en compétition.

Purpose: The aim of this study was i) to evaluate changes in leg-spring behavior during an exhaustiverun in elite triathletes and ii) to determine whether these modifications were related to an increase inthe energy cast of running (Cr).Methods: Ni ne elite triathletes ran to exhaustion on an indoor track at a constant velocity correspondingto 95% of the velocity associated with the maximal oxygen uptake (5.1 ±0.3 m.s-1; mean ti me toexhaustion: 10.7 ±2.6 min. Vertical and horizontal ground reaction forces were measured every lap(200 m) by a 5 m long force platform system. Cr was measured from pulmonary gas exchange using abreath-by-breath portable gas analyser.Results: Leg stiffness (-13.1%; P

International audience; The increase of sedentary lifestyle in the French population and the decrease in the time daily devoted to physical activity has raised public concerns. Promotional campaigns to raise energy expenditure and health awareness have recently increased. Nevertheless, although the recognition of such an imbalance is becoming more evident in the population, a real beneficial modification is still far from a full success. Numerous working groups are seeking to broaden the scope of action and take advantage of environments that facilitate the application of strategies. Local settings such as schools, businesses, urban authorities and sports representatives (clubs, leagues and associations) progressively increase their engagement. Through large collective participations gathered in the PNNS initiative (Plan National Nutrition Santé 2011-2015), we may witness a growing investment in the energy balance, an area that has been neglected so far.; L'augmentation de la sédentarité des français et la diminution de la pratique des activités physiques ou sportives (APS) favorables à la santé suscitent de nombreuses tentatives publiques et campagnes de promotion visant à favoriser la dépense énergétique. Mais si la conscience de ce déséquilibre apparaît de plus en plus clairement dans la population, le passage à l'acte est encore loin d'être réussi. C'est pourquoi se mettent en place de nombreux groupes de travail et de réflexion cherchant à élargir les champs d'action mais surtout à tirer parti de tous les environnements favorables à cette remise en forme. L'école, l'entreprise, les collectivités territoriales ou les acteurs du sport (clubs, ligues, associations) sont de plus en plus impliqués dans la participation à ce grand mouvement, qui verra, par le biais du PNNS 2011-2015, croître l'investissement dans un domaine un peu négligé jusque là : celui de l'équilibre énergétique.