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International audience; The planning of any motor action requires a complex multisensory processing by the brain. Gravity - immutable on Earth - has been shown to be a key input to these mechanisms. Seminal fMRI studies performed during visual perception of falling objects and self-motion demonstrated that humans represent the action of gravity in parts of the cortical vestibular system; in particular, the insular cortex and the cerebellum. However, little is known as to whether a specific neural network is engaged when processing non-visual signals relevant to gravity. We asked participants to perform vertical and horizontal hand movements without visual control, while lying in a 3T-MRI scanner. We highlighted brain regions activated in the processing of vertical movements, for which the effects of gravity changed during execution. Precisely, the left insula was activated in vertical movements and not in horizontal movements. Moreover, the network identified by contrasting vertical and horizontal movements overlapped with neural correlates previously associated to the processing of simulated self-motion and visual perception of the vertical direction. Interestingly, we found that the insular cortex activity is direction-dependent which suggests that this brain region processes the effects of gravity on the moving limbs through non-visual signals.

International audience; In this study, we utilized transformed spatial mappings to perturb visuomotor integration in 5-yr-old children and adults. The participants were asked to perform pointing movements under five different conditions of visuomotor rotation (from 0° to 180°), which were designed to reveal explicit vs. implicit representations as well as the mechanisms underlying the visual-motor mapping. Several tests allowed us to separately evaluate sensorimotor (i.e., the dynamic dimension of movement) and cognitive (i.e., the explicit representations of target position and the strategies used by the participants) representations of visuo-proprioceptive distortion. Our results indicate that children do not establish representations in the same manner as adults and that children exhibit multiple visuomotor representations. Sensorimotor representations were relatively precise, presumably due to the recovery of proprioceptive information and efferent copy. Furthermore, a bidirectional mechanism was used to re-map visual and motor spaces. In contrast, cognitive representations were supplied with visual information and followed a unidirectional visual-motor mapping. Therefore, it appears that sensorimotor mechanisms develop before the use of explicit strategies during development, and young children showed impaired visuomotor adaptation when confronted with large distortions.

Epub 2015 Oct.; Previous studies have reported that reaction time in gait initiation was affected by emotion eliciting pictures. This study examined the effect of a change in the delay between image onset and the imperative “go” on reaction time. From a standing posture, 19 young adults had to walk (several steps) toward pleasant or unpleasant images in two conditions. In the short condition, the word “go” appeared 500 ms after image onset and participants were instructed to initiate gait as soon as possible after the word go appeared. In the long condition, the same procedure was used but the word “go” appeared 3000 ms after image onset. Results demonstrated that motor responses were faster for pleasant pictures than unpleasant ones in the short condition. In contrast, no significant difference was found between both categories of pictures in the long condition. Moreover, we found that self ratings of valence of unpleasant pictures were less unpleasant in the long condition than in the short one whereas there was no difference for pleasant pictures between both conditions. This result reflected a change in the affective significance of unpleasant pictures in the long condition. We also found in the long condition, that the body was inclined forward and to the stance limb during the standing posture and importantly with a similar extent for pleasant and unpleasant pictures. This change clearly reflected a facilitation of the gait initiation process. Overall, results suggested that this gait facilitation when confronted to unpleasant pictures resulted from emotional regulation processes enabling to reappraise these pictures and to override the initial avoidance tendency that they caused.

Purpose. Inducing a negative stereotype toward women usually leads to a decrease in women performance and an increase in men performance. These effects were observed during technical tasks. The pur...

International audience; Anorexia nervosa (AN) is frequently associated with anxiety, depression, and problematic exercise (PE). These uncontrolled physical activities inducing resistance to the therapeutic protocols. Some recent studies demonstrated that adding controlled and adapted physical activities (APA) in the therapeutic protocol was more positive for AN patients than the usual physical activity suppression. The aim of the present study was to highlight different profiles of AN patients in order to better individually adapt the physical activity programs, and thus the therapeutic impact of the future APA programs. Problematic exercises, cardio-respiratory fitness, perceived fitness and mood were measured in fifty-two AN patients [all females, 17.15 (± 2.22) years old, BMI = 16.49 (± 1.54)] from three different French therapeutic centers. Then, a latent profile analysis allowed to exhibit 3 classes corresponding to 3 different profiles of AN patients. A first patient profile was characterized by proven PE with lower anxiety and depression. A second profile exhibited a moderate PE coupled with a high level of anxiety and depression. The last profile revealed patients without any PE, and medium scores in the other variables. These results lead to propose different angles and objectives to design and improve future APA programs according to these patient profiles.; Une analyse en classes latentes révèle différentes catégories de patients dans l’anorexie mentale: proposition de lignes directrices en matière d’activité physique adaptée. Les patients souffrant d’anorexie mentale (AM) présentent souvent des symptômes d’anxiété, de dépression, et une pratique problématique d’activité physique (PPAP). Cette PPAP induit une résistance aux protocoles thérapeutiques. En revanche, des études récentes ont démontré que l’utilisation d’activités physiques adaptées (APA) était meilleure pour ces patientes qu’une privation totale d’exercice physique. L’objectif de cette étude est de mettre en lumière différents profils de patientes AM afin de permettre une meilleure individualisation des contenus des programmes d’APA. La PPAP, la condition physique perçue, l’adaptation cardiaque à l’effort, les niveaux d’anxiété et de dépression ont été mesurés chez cinquante-deux patientes anorexiques [17,15 (± 2,22) ans, IMC = 16,49(± 1,54)]. Ensuite, une analyse en classes latentes des scores a permis de mettre en lumière 3 profils cliniques significativement différents. Le premier profil est caractérisé par une PPAP totale associée à de faibles niveaux d’anxiété et de dépression. Le second est caractérisé par une PPAP symptomatique, mais un très haut niveau d’anxiété et de dépression. Enfin, le troisième profil présente des patientes sans PPAP et des scores moyens dans les autres variables. Ces résultats nous conduisent à proposer différents angles et objectifs pour réaliser des programmes d’APA en fonction du type de profil des patientes prises en charge.

International audience; Founded as the Bureau Des Fédérations Européennes De Gymnastique in 1881, the International Gymnastics Federation (FIG) was officially created in 1922. However, despite having over 100 national associations affiliated by the end of the twentieth century, it was dominated by Europeans until relatively recently. In particular, the former communist bloc of Eastern Europe had a particular hold on gymnastics from the 1950s onwards. This article uses the FIG as a case study to highlight the institutional, political and ideological rivalries within international sport. It reveals such influences on the sportification of gymnastics and, in doing so, offers new insights into the history of the Cold War, including the USSR’s ascension to the international sporting scene, and its power surrounding the ‘South Africa ban’ due to its Apartheid policy. Thus, this work allows us to understand how the FIG’s policies were, from an early stage, embedded in a twofold dynamic of East–West and North–South. Our study is based on official and administrative documents from national associations and the FIG, and on press review from several European countries.

International audience; This study aimed to explore attentional foci and their temporal patterns in expert skaters in real competition situations. Individual self-confrontation interviews were held with 8 expert figure skaters while they watched their videotaped program performed in official competitions. Qualitative data analysis revealed that skaters used a substantial number of loci, which were classified by content and characteristics. Event listing was used to display the patterns of foci over time, revealing that skaters used distinct processes to prepare for, perform, and evaluate different program elements. These results highlighted the great flexibility and variability of attentional focus, according to circumstantial factors.

Athletes and coaches believe that adequate sleep is essential for peak performance. There is ample scientific evidence which support the conclusion that sleep loss seems to stress many physiological functions in humans. The aim of this study was to determine the effect of one night's sleep deprivation on intermittent exercise performance in the evening of the following day. Ten male Taekwondo players performed the Yo-Yo intermittent recovery test (YYIRT) in three sleep conditions (reference sleep night [RN], partial sleep deprivation at the beginning of night [PSDBN], partial sleep deprivation at the end of night [PSDEN]) in a counterbalanced order, allowing a recovery period ≥q36 hr in between them. Heart rate peak (HRpeak), plasma lactate concentrations (Lac) and rating of perceived exertion (RPE) were measured during the test. A significant effect of sleep restriction was observed on the total distance covered in YYIRT (P

International audience; Motion as encoded in linguistic cues is used to differentiate affective valence and dominance. Participants were invited to rate their affective responses to different words along valence and dominance scales. The words were nouns describing static cues and verbs describing motion, connected to DOWN/UP and Avoidance/Approach cues. The results of three studies showed that valence and dominance could be differentiated through syntax and semantics of motion. On one hand, dominance feelings, compared to valence ones, are particularly influenced by motion encoded in syntactic classes (verbs vs. nouns). On the other hand, valence feelings, compared to dominance ones, are influenced by a semantics of motion through DOWN/UP and Avoidance/Approach cues, considered as polarities. A polarity correspondence effect is proposed to explain these results.

Epub 2015 Oct 26. Erratum in: Exp Brain Res. 2016 Apr.; This study explored the directional specificity of fear of falling (FoF) effects on the stabilizing function of anticipatory postural adjustments (APA). Participants (N = 71) performed a series of lateral leg raises from an elevated surface in three conditions: in the "Control condition", participants stood at the middle of the surface; in the two test conditions, participants were positioned at the lateral edge of the surface so that the shift of the whole-body centre-of-mass during APA for leg raising was directed towards the edge ("Approach condition") or was directed away from the edge ("Avoidance condition"). Results showed that the amplitude of APA was lower in the "Approach condition" than in the "Control condition" (p < .01); this reduction was compensated for by an increase in APA duration (p < .05), so that both postural stability and motor performance (in terms of peak leg velocity, final leg posture and movement duration) remained unchanged. These changes in APA parameters were not present in the "Avoidance condition". Participants further self-reported a greater FoF (p < .001) and a lower ability to avoid a fall (p < .001) in the "Approach condition" (but not in the "Avoidance condition") than in the "Control condition". The results of this study show that the effects of FoF do not solely depend on initial environmental conditions, but also on the direction of APA relative to the location of the postural threat. These results support the so-called Motivational Direction Hypothesis, according to which approach and avoidance behaviours are primed by emotional state.

International audience; Performing approach vs. avoidance behaviors (arm flexion vs. arm extension) on the one hand, and lateralized peripheral activations (left side vs. right side) of the motivational systems of approach vs. avoidance, on the other hand, have been shown to impact on cognitive functioning (Cretenet, & Dru, 2009), mainly in judgment tasks. When a unilateral motor congruent behavior; that is, a behavior that activates the same motivational system (e.g., flexion of the right arm) was performed during a judgment task, participants' use of complex, interactive information integration rules was facilitated. No effect was, however, found when simpler, additive rules were involved (Mullet, Cretenet, & Dru, 2014). Three experiments are reported here that examined the effect of bilateral motor behaviors (e.g., flexion of the right arm and extension of the left arm) on the implementation of information integration rules. In Studies 1 and 2, two judgment tasks similar to the ones used by Mullet et al. (2014) were used: (a) a complex task in which participants judged a person's attractiveness from personality information, and (b) a simpler task in which they attributed blame according to bad deeds. It was found that similar motor behaviors performed by the two arms (e.g., flexion of both arms), in contrast to dissimilar ones, facilitated the use of complex, interactive information integration rules. No effect was found in the case of simpler integration rules. In Study 3, these results were replicated in a judgment task in which the complexity of the integration rule varied depending on the instructions given. Overall, when bilateral motor behaviors were performed during judgment, facilitation in the use of complex integration rules no longer depended on motivational congruence as in the case of unilateral motor behavior. It depended on symmetry/similarity of behaviors.

International audience; Objective : Our aim is to investigate the links between duration and intensity of exercise and the nutritional status in terms of body composition in acute anorexia nervosa (AN) patients.Method : One hundred ninety‐one hospitalized women suffering from AN were included. Exercise duration and intensity were assessed using a semistructured questionnaire. Body composition was measured using bioelectrical impedance. Linear multiple regression analyses were carried out using body mass index, fat‐free mass index, and fat mass index as dependent variables and including systematically exercise duration, exercise intensity, and other confounding variables described in the literature that were significantly associated with each dependent variable in univariate analysis. Results: A lower BMI was linked to lower exercise intensity, AN restrictive type, and presence of amenorrhea. A lower FFMI was linked to lower exercise intensity, older age, AN restrictive type, and premenarchal AN. Duration of exercise was not linked to the nutritional status. Conclusions: Exercising at higher intensity in AN is associated with a better nutritional status, thus, a better resistance to starvation. The impact of therapeutic physical activity sessions, adapted in terms of exercise intensity and patient's clinical status, should be evaluated during nutrition rehabilitation.

International audience; Functional imaging enables to detect and to localize brain areas specifically involved in networks subserving a given mental activity. The two main techniques used in routine consist in functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). We will focus on fMRI. fMRI is based on the local and transient increase of blood oxygenation in the cortical and deep nuclear microvasculature, caused by neuronal activation. This hemodynamic phenomenon called blood-oxygenation level-dependent (BOLD) response only indirectly reflects the amount of neuronal activity (Raichle ME, Proc Natl Acad Sci USA 93:765–772, 1998). This local blood hyperoxygenation produces microscopic magnetic field alterations measurable by appropriate T2*-weighted MRI sequence. A complex image and statistical post-processing is then applied to raw data to generate final “brain activation maps.” These functional maps can be acquired during active stimulation protocols, or “at rest” (resting-state functional connectivity, rsfMRI). fMRI and rsfMRI resort to different algorithmic processing: linear model-related algorithms and nonlinear, model-free, data-driven algorithms, respectively, even if these latter methods can also be applied to fMRI data. This functional connectivity can be complemented by effective connectivity which seeks causality relationships between brain areas participating to a same circuit. Finally, advanced algorithms can also explore the topology of the neural networks and provide new and richer graph-theoretic related information, and machine learning will improve normal and aberrant structural and functional brain pattern recognition and classification.; CITATIONS 0 READS 34 2 authors: Some of the authors of this publication are also working on these related projects: Brain plasticity in aquired visual loss View project Sclérose Latérale Amyotrophique (SLA) : développement d'un système auditif de détection de la voix et suivi des patients par l'activité physique et impact sur la qualité de vie View project Christophe Habas CHNO des Quinze-Vingts The user has requested enhancement of the downloaded file.

International audience; Great progress has been made in understanding how people make financial decisions. However, there is little research on how people make health and treatment choices. Our study aimed to examine how participants weigh benefits (reduction in disease progression) and probability of risk (medications' side effects) when making hypothetical treatment decisions, and to identify the neural networks implicated in this process. Fourteen healthy participants were recruited to perform a treatment decision probability discounting task using MRI. Behavioral responses and skin conductance responses (SCRs) were measured. A whole brain analysis were performed to compare activity changes between "mild" and "severe" medications' side effects conditions. Then, orbitofrontal cortex (OFC), ventral striatum (VS), amygdala and insula were chosen for effective connectivity analysis. Behavioral data showed that participants are more likely to refuse medication when side effects are high and efficacy is low. SCRs values were significantly higher when people made medication decisions in the severe compared to mild condition. Functionally, OFC and VS were activated in the mild condition and were associated with increased likehood of choosing to take medication (higher area under the curve "AUC" side effects/efficacy). These regions also demonstrated an increased effective connectivity when participants valued treatment benefits. By contrast, the OFC, insula and amygdala were activated in the severe condition and were associated with and increased likelihood to refuse treatment. These regions showed enhanced effective connectivity when participants were confronted with increased side effects everity. This is the first study to examine the behavioral and neural bases of medical decision making.

Sleep loss is among the most common yet frequently overlooked problems. This disruptive influence is associated with an adverse lipid profile (LP) and consequently results in an increased risk of cardiovascular disease. Furthermore, it has been well established that athletes are increasingly confronted with sleep problems. The aim of this study was to explore the effect of one night of partial sleep deprivation (PSD) on the cardiovascular profile and LP in young, trained athletes. Ten male Taekwondo athletes were randomized for three sleep conditions in a counterbalanced order: (i) following a baseline sleep night (BN), (ii) following PSD at the beginning of the night (PSDBN), and (iii) following PSD at the end of the night (PSDEN). Basal cardiovascular physiological measures were recorded, and blood samples were taken in the fasted state following each sleep session (i.e., in the morning at 07:00 h). The results showed that myoglobin and creatine phosphokinase increased significantly after PSDEN but not after PSDBN. By contrast, no alteration was observed in the LP and physiological parameters following the two types of PSD. In conclusion, these results show that PSDEN increases cardiac damage biomarkers significantly, even though they do not reach clinical significance. Thus, one night of PSD does not affect the physiological responses and biomarkers of LP in Taekwondo athletes.

International audience; Attention deficit disorder with or without hyperactivity (ADD/ADHD) is a neurodevelopmental disorder that can be exacerbated by psychosocial factors. Various studies confirm that the severity of a psychiatric disorder, particularly when it comes to ADHD, is strongly correlated with the amount of use. This study (1) evaluated the association between ADHD and gambling among young students; (2) determined which symptom among ADHD's three symptoms (attention deficit, hyperactivity, or impulsivity) had the strongest association with video game addiction and gambling; and (3) determined the impact of the association between ADHD and video game addiction and gambling on self-esteem and academic performance of students. A total of 720 students (445 males and 274 females) were recruited from eight higher educational institutions of Ile de France. They all completed a battery of questionnaire consisting of Canadian Problem Gambling Index, UPPS Impulsive Behavior Scale, Wender Utah Rating Scale (WURS), Adult ADHD Self-Report Scale (ASRS) and Rosenberg scales, and socio-demographic data. 13.33 % of the participants had symptoms of ADHD during childhood (WURS scale score) and 40.41 % of them have symptoms of ADHD in adulthood (ASRS score). Finally, among the participants, 37.5 % had excessive gambling addiction, have positive results on WURS and ASRS scales, thus having a probable ADHD, whereas 14.55 % had no gambling addiction. The results demonstrated that adult ADHD was associated with gambling addiction. Significant associations were observed between ADHD and impulsivity, academic difficulties and gambling addiction. The association between ADHD and gambling seems to be common among vulnerable populations such as adolescents and could be related to variables such as self-esteem, which appears to potentially worsen the prognosis. Further research on this relationship is needed to optimize prevention strategies and effective treatment.

International audience; Behavioral addictions are of growing interest in today's world indicating the need for novel therapeutic methods of biopsychosocial type. Amongst the numerous behavioral addictions, our clinical experience at CAPS (Centre d'Accompagnement et de Prévention pour les Sportifs) brought to our attention the problem of exercise dependency in sports population. This addiction categorized as positive addiction faces a significant problem with respect to definitions, epidemiology, models, diagnostic criteria and measurement scales. Through this clinical case study, we intend to throw light upon the different aspects of this addiction, particularly its co-occurrence with eating disorders and methods of treatment. Unlike other addictions where the consequences are said to be harmful, exercise dependency is valorized by the individual and society. This article also throws light upon the different measurement scales used to quantify exercise dependency. It also discusses the clinical significance of a tool being currently validated which aims to evaluate the intricacy of exercise dependency and eating disorders. (PsycINFO Database Record (c) 2015 APA, all rights reserved). (journal abstract)

Background and aims: Despite many positive benefits, mobile phone use can be associated with harmful and detrimental behaviors. The aim of this study was twofold: to examine (a) cross-cultural patterns of perceived dependence on mobile phones in ten European countries, first, grouped in four different regions (North: Finland and UK; South: Spain and Italy; East: Hungary and Poland; West: France, Belgium, Germany, and Switzerland), and second by country, and (b) how socio-demographics, geographic differences, mobile phone usage patterns, and associated activities predicted this perceived dependence.\ud \ud Methods: A sample of 2,775 young adults (aged 18–29 years) were recruited in different European Universities who participated in an online survey. Measures included socio-demographic variables, patterns of mobile phone use, and the dependence subscale of a short version of the Problematic Mobile Phone Use Questionnaire (PMPUQ; Billieux, Van der Linden, & Rochat, 2008).\ud \ud Results: The young adults from the Northern and Southern regions reported the heaviest use of mobile phones, whereas perceived dependence was less prevalent in the Eastern region. However, the proportion of highly dependent mobile phone users was more elevated in Belgium, UK, and France. Regression analysis identified several risk factors for increased scores on the PMPUQ dependence subscale, namely using mobile phones daily, being female, engaging in social networking, playing video games, shopping and viewing TV shows through the Internet, chatting and messaging, and using mobile phones for downloading-related activities.\ud \ud Discussion and conclusions: Self-reported dependence on mobile phone use is influenced by frequency and specific application usage.

International audience; The present research investigated the influence of coaches' exclamations on referees' decision-making in judo. Under time pressure, 65 judo referees judged identical throw situations played on video. The coaches' exclamations during throws were audible in the experimental condition, whereas no sound was present in the control condition. The throw situations varied in ambiguity (low vs. high) and strength (minor sanctions vs. hard sanctions), while coaches' exclamations interpreted the throws in a manner that was congenial for their own competitor. Results indicated that referees may use an audience response heuristic or a consensus heuristic to help them make decisions.

Few studies have focused on the effect of posture during sprint start. The aim of this study was to measure the effect of the modification of horizontal distance between the blocks during sprint start on three dimensional (3D) joint angular velocity. Nine trained sprinters started using three different starting positions (bunched, medium and elongated). They were equipped with 63 passive reflective markers, and an opto-electronic Motion Analysis1 system was used to collect the 3D marker trajectories. During the pushing phase on the blocks, norm of the joint angular velocity (NJAV), 3D Euler angular velocity (EAV) and pushing time on the blocks were calculated. The results demonstrated that the decrease of the block spacing induces an opposite effect on the angular velocity of joints of the lower and the upper limbs. The NJAV of the upper limbs is greater in the bunched start, whereas the NJAV of the lower limbs is smaller. The modifications of NJAV were due to a combination of the movement of the joints in the different degrees of freedom. The medium start seems to be the best compromise because it leads, in a short pushing time, to a combination of optimal joint velocities for upper and lower segments.

International audience; " STAPS " journal and interdisciplinarity: a socio-computer study Since an analysis with Prospero software of 602 articles published in STAPS journal between 1980 and 2010, our research identifies the diversity of interdisciplinary forms in scientific texts. The preoccupation of interdisciplinarity is constant even if it acknowledgement seems difficult. Our analysis also detects superficial allusions than demands. Interdisciplinarity is then showed as an efficient way to understand complex subjects, to connect researches with social demand, to generate scientific productivity or creativity. The demand of interdisciplinarity is also associated to a territorial defense from some scientific tendencies less recognized. Rarely, interdisciplinarity is too considered as an object of analysis or could also be criticized. When we consider forms of cohabitation of diverse disciplinary vocabulary in a same article, we identify more or less frequent mixes. We notice that the questions of teaching generate the association of a minimum of two disciplinary vocabularies. Finally, considering operations of contextualization of a research object from another disciplinary point of view or a critical discussion within two disciplinary tendencies, the interdisciplinarity work in scientific articles looks like a reflexive activity of the way to produce science; À partir d'une analyse de 602 articles de la Revue STAPS publiés entre 1980 et 2010, s'appuyant sur le logiciel Prospero, la recherche se propose de repérer la pluralité des formes que peut prendre l'interdisciplinarité au sein des textes scientifiques. La préoccupation d'interdisciplinarité apparaît constante et sa difficile reconnaissance est soulignée. On rencontre aussi bien des allusions superficielles à la notion que des revendications. L'interdisciplinarité est alors présentée comme pertinente pour éclairer certains objets complexes, rapprocher les recherches de la demande sociale, favoriser la productivité ou la créativité scientifique. Le mot d'ordre d'interdisciplinarité peut également être associé à des logiques de défense territoriale de courants de pensée menacés. Plus rarement, l'interdisciplinarité est prise comme objet d'étude voire critiquée. Lors de l'analyse des formes de cohabitation de lexiques disciplinaires dans un même article, nous repérons ensuite les mélanges plus ou moins fréquents. On note que les questions d'enseignement génèrent la convocation d'au moins deux lexiques disciplinaires. Enfin, qu'il s'agisse d'opérations de contextualisation de l'objet de recherche via une autre discipline ou de discussions critiques entre deux domaines de connaissance, nous soulignons que l'activité interdisciplinaire engage dans les textes eux-mêmes un travail réflexif sur les façons de faire de la science.

Epub ahead of print; BACKGROUND: The effects of a six-week maximal voluntary isometric co-contraction (MIVCC) training program of the elbow flexor and extensor muscles on maximal and explosive muscle strength have been studied. METHODS: Sixteen active men underwent 6-week MIVCC. Maximal rate of force development (MRFD) of the elbow flexor (MRFDflex) and extensor (MRFDext) were measured in addition to maximal voluntary contraction (MVC) of these muscles (MVCflex and MVCext) before (T0), after 4-week (T1) and 6-week (T2) MIVCC training program. During each test session, integrated electromyographic activity (iEMG) of agonistic and antagonistic muscles during MVC, MRFD, submaximal contractions (30 and 60% MVC) and MIVCC of the elbow flexor and extensor muscles were measured. RESULTS: At T2, MVCflex (13.3±11.7%) and MVCext (22.5±6.1%) increased significantly (P

The study investigated the effect of the time-of-day at which maximal isometric voluntary co-contraction (MIVCC) training is conducted on the adaptation and diurnal variation of maximal and explosive force production. Twenty active men underwent a 6-week (3 times per week) MIVCC training of the right elbow joint. The participants were randomly assigned to a morning training group (MTG, 07:00-08:00 hours) and evening training group (ETG, 17:00-18:00 hours). The maximal voluntary force (MVF) and maximal rate of force development (MRFD) during isometric elbow flexion (MVFF and MRFD(F)) and extension (MVF(E) and MRFD(E)) were recorded before (T0) and after (T1) training in the morning and evening. At T0, MVF and MRFD were higher in the evening compared with those in the morning for the MTG and ETG (p ≤q 0.05). At T1, MVFF and MVFE increased in the morning and evening for both groups (p < 0.001). The MRFD(F) and MRFD(E) increased only if training and test session were scheduled at the same time. The relative increase of MVF was greater at the specific time of training for the MTG (12 and 17.6% in MVF(F) and MVF(E), respectively) and ETG (9.8 and 13.4% in MVF(F) and MVF(E), respectively). The diurnal variations in MVF and MRF(D) during flexion and extension disappeared in the MTG and persisted in the ETG. Maximal isometric voluntary co-contraction training enhanced muscle strength whatever the time-of-day at which the training was scheduled without alteration of explosive force. In contrast, to optimize the muscle strength, our results suggested that morning training may be accompanied by the greatest muscle strength gain and blunted muscle strength variation observed between the morning and evening.

Published: 24 August 2016 Only a small fraction of all the information reaching our senses can be the object of conscious report or voluntary action. Although some models propose that different attentional states (top-down amplification and vigilance) are necessary for conscious perception, few studies have explored how the brain activations associated with different attentional systems (such as top-down orienting and phasic alerting) lead to conscious perception of subsequent visual stimulation. The aim of the present study was to investigate the neural mechanisms associated with endogenous spatial attention and phasic alertness, and their interaction with the conscious perception of near-threshold stimuli. The only region demonstrating a neural interaction between endogenous attention and conscious perception was the thalamus, while a larger network of cortical and subcortical brain activations, typically associated with phasic alerting, was highly correlated with participants’ conscious reports. Activation of the anterior cingulate cortex, supplementary motor area, frontal eye fields, thalamus, and caudate nucleus was related to perceptual consciousness. These data suggest that not all attentional systems are equally effective in enhancing conscious perception, highlighting the importance of thalamo-cortical circuits on the interactions between alerting and consciousness. ABC was supported by a Ramón y Cajal fellowship from the Spanish Ministry of Education and Science. DB and FB were supported by postdoctoral grants from the eraNET-NEURON BEYONDVIS project. PMP-A was supported by a Ramón y Cajal fellowship (RYC-2014-15440), and grants PSI2015-65696 and SEV-2015-049 from the Spanish Ministry of Economy and Competitiveness (MINECO). Research was funded by research projects PSI2008-03595PSIC, PSI2011-22416, and eraNET-NEURON BEYONDVIS, EUI2009-04082 to PB; and PSI2014-58681-P and Ramón y Cajal research project RYC-2011-09320 to Ana B. Chica.

Epub 2012 Apr 24; International audience; This study aimed at determining the upper limb muscles coordination during a power backward giant swing (PBGS) and the recruitment pattern of motor units (MU) of co-activated muscles. The wavelet transformation (WT) was applied to the surface electromyographic (EMG) signal of eight shoulder muscles. Total gymnast's body energy and wavelet synergies extracted from the WT-EMG by using a non-negative matrix factorization were analyzed as a function of the body position angle of the gymnast. A cross-correlation analysis of the EMG patterns allowed determining two main groups of co-activated muscles. Two wavelet synergies representing the main spectral features (82% of the variance accounted for) discriminated the recruitment of MU. Although no task-group of MU was found among the muscles, it appeared that a higher proportion of fast MU was recruited within the muscles of the first group during the upper part of the PBGS. The last increase of total body energy before bar release was induced by the recruitment of the muscles of the second group but did not necessitate the recruitment of a higher proportion of fast MU. Such muscle coordination agreed with previous simulations of elements on high bar as well as the findings related to the recruitment of MU.

International audience; OBJECTIVES: The present study is an attempt to experimentally induce a younger subjective age among older adults and to test whether they show better physical functioning when they are induced to feel younger.METHOD: Participants were 49 older adults aged between 52 and 91 years. Following an initial measure of handgrip performance as an indicator of physical functioning, participants in the experimental condition received positive feedback regarding their performance compared with their same-aged peers, whereas participants in the control condition did not receive any information. Participants in both groups then completed a second handgrip measure. Subjective age was assessed before the initial handgrip task and after the experimental manipulation.RESULTS: Participants in the experimental group felt younger than their age and showed a significant increase in grip strength, whereas no changes in subjective age and grip strength were observed in the control condition.DISCUSSION: This study is among the first to induce a younger subjective age. It supports the notion that redirecting older adults' attention to downward social comparison with same-aged peers is a promising strategy to maintain a sense of feeling younger. In addition, our results provide an initial positive answer to the question of whether feeling younger translates into better physical functioning.

Epub ahead of print; This study aimed to compare the force (F)-velocity (v)-power (P)-time (t) relationships of female and male world-class sprinters. A total of 100 distance-time curves (50 women and 50 men) were computed from international 100-m finals, to determine the acceleration and deceleration phases of each race: (a) mechanical variables describing the velocity, force, and power output; and (b) F-P-v relationships and associated maximal power output, theoretical force and velocity produced by each athlete (Pmax , F0 , and V0). The results showed that the maximal sprint velocity (Vmax ) and mean power output (W/kg) developed over the entire 100~m strongly influenced 100-m performance (r>-0.80; P≤q0.001). With the exception of mean force (N/kg) developed during the acceleration phase or during the entire 100~m, all of the mechanicals variables observed over the race were greater in men. Shorter acceleration and longer deceleration in women may explain both their lower Vmax and their greater decrease in velocity, and in turn their lower performance level, which can be explained by their higher V0 and its correlation with performance. This highlights the importance of the capability to keep applying horizontal force to the ground at high velocities.

International audience; In literature, there exists disagreement regarding the impact of comorbid personality disorder(s) (PD[s]) on treatment outcome for patients with major depressive disorder (MDD). The aim of this paper was to investigate whether statistical heterogeneity and inter-dependency are potential moderators of the effect of co-morbid PDs on outcome for patients with MDD. Clinician-rated MADRS scores and DSM-IV Axis II personality disorder diagnoses were obtained from 562 outpatients with MDD who received 6 months of combined psycho- and pharmacotherapy. Single-level regression showed significantly worse treatment outcome among patients with co-morbid PD, as compared to patients with no PD. After controlling for statistical heterogeneity and interdependency, treatment outcome was no longer significantly worse for patients with co-morbid PD. In conclusion, heteroscedasticity and inter-dependency should be considered as potentially compelling explanations for inconsistencies in findings on treatment outcome for depressed patients with co-morbid PDs.

International audience; Gait initiation (GI) is the transient period between posture and movement. Its central programming takes into account the environmental constraints as well as the constraints induced by the body itself. Patients with peripheral sensory neuropathies display a severe proprioceptive deficit leading to balance and gait impairments and rely on a variety of compensatory mechanisms and are known to be dependent on vision. GI was studied on eight healthy subjects and five patients in order to assess the effect of somatosensory loss on the different phases of GI, combined with a manipulation of the visual inputs. Our main hypothesis is that the proprioceptive deficit would induce an adaptation of the GI process, especially when modifying the lower part of peripheral vision. The results show that the pathology induces some adaptations of the GI process, characterized by a decrease of the motor performance (assessed by the maximal anteroposterior velocity of the center of gravity at the end of the first step), a decrease in the spatial parameters (assessed by the peak amplitude of the backward shift of the center of foot pressure during the anticipation phase and the length of the first step), and a non-modification of the temporal parameters (assessed by the duration of the anticipation phase and of the first step). The suppression of the lower part of peripheral vision has no effect on the GI process. The role of the lower part of peripheral vision seems therefore to be less critical for GI, than for balance and locomotion.

Purpose: To prove the feasibility of arterial spin labeling (ASL) to explore brain tumors by comparing dynamic susceptibility contrast-enhanced MRI to ASL at 3T MR. Materials and Methods: Twenty-seven patients were included presenting 9 gliomas, 10 metastases and 8 meningiomas. All were explored by a pseudo-continuous ASL and dynamic susceptibility contrast-enhanced T2* perfusion sequence. Two neuroradiologists analyzed the cerebral blood flow (CBF) maps to assess feasibility, examination quality and quantitative comparison. The Spearman nonparametric correlation test and the Bland-Altman graphic test were used to analyze our quantitative results. Results: 92% of ASL CBF maps were informative. ASL detected all lesions as well as dynamic susceptibility contrast-enhanced MRI. Both sequences provide relative quantitative CBF values closely correlated. Conclusion: On a 3T MR unit, ASL is a good alternative to dynamic susceptibility contrast-enhanced MRI when contrast medium is contraindicated or intravenous injection is not possible. Its results on relative CBF parameters are similar to contrast-injected perfusion.

International audience; The description of specific circuits in networks should allow a more realistic definition of dynamic functioning of the central nervous system which underlies various brain functions. After introducing the programmed and acquired networks and recalling the concepts of functional and effective connectivity, we presented biophysical and physiological aspects of the BOLD signal. Then, we briefly presented a few data-driven and hypothesis-driven methods; in particular we described structural equation modeling (SEM), a hypothesis-driven approach used to explore circuits within networks and model spatially and anatomically interconnected regions. We compared the SEM method with an alternative hypothesis-driven method, dynamic causal modeling (DCM). Finally, we presented independent components analysis (ICA), an exploratory data-driven approach which could be used to complete the directed brain interactivity studies. ICA combined with SEM/DCM may allow extension of the statistical and explanatory power of fMRI data.

This investigation tests a reconceptualization of ethnocentrism based primarily on Sumner's definitions. Ethnocentrism is reconceptualized as ethnic group self-centeredness, with four intergroup expressions of ingroup preference, superiority, purity, and exploitativeness, and two intragroup expressions of group cohesion and devotion. The reconceptualization was supported in Study 1 among 350 New Zealand participants and in Study 2 among 212 US, 208 Serbian, and 279 French participants. Ethnocentrism in each country consisted of two correlated second-order factors representing intergroup and intragroup ethnocentrism and six first-order factors representing the six primary expressions. Analyses in Study 2 supported the measurement invariance of the scale and a third-order factor model, with one ethnocentrism factor at the broadest level of generalization. Ethnocentrism was empirically distinct from outgroup negativity and mere ingroup positivity. Intragroup ethnocentrism appeared primarily based on ethnic insecurity, personal self-transcendence, and ethnic identification, whereas intergroup ethnocentrism appeared primarily based on self-aggrandizement, warlikeness, and generally chauvinistic attitudes. Accordingly, although related, the two kinds of ethnocentrism tend to have quite differential implications for group attitudes and behaviors. Copyright © 2008 John Wiley & Sons, Ltd. This article was published online on 31 December 2008. Errors were subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected [date to be added later].

L’idée de ce dossier thématique est née d’un double constat : celui de l’importance prise par le corps en anthropologie ces dernières années et celui de l’évitement de la question de la matérialité du corps dans ces mêmes recherches. Il suffit de porter le regard sur la multiplication et le foisonnement des recherches qui abordent le corps dans les sciences sociales et humaines pour comprendre l’importance prise par ces questions en ce moment. Il ne passe pratiquement pas une semaine sans que...

These experiments examined the cognitive processes involved in judging the quality of play of a player competing against another player and the overall interest of a competitive game as a function of the players’ respective ability and motivation levels. For the quality of play of one player, a very simple information integration rule was found. Quality of play was judged almost exclusively as an additive function of the ability and motivation levels of the player. For the interest of the game, an apparently complex but fundamentally simple integration rule was found. For a game to be very interesting, players had to be both highly able and highly motivated; for a game to be somewhat interesting, each player had to be at least either highly able or highly motivated; and all other configurations corresponded to lower expected levels of interest.

International audience; Cet article se propose d’examiner le rôle de la presse dans deux affaires touchant le sport : d’une part, l’affaire du Tour de France cycliste 1998 marqué par les révélations de l’ampleur du dopage et d’autre part la polémique divulguant la présence clandestine de footballeurs mineurs africains dans les clubs français. A partir de corpus textuels analysés avec le logiciel Prospéro, nous avons étudié ce qui caractérise les productions médiatiques par rapport aux prises de paroles des autres protagonistes. Cela nous a conduits à étudier les relations entre les différents acteurs et les journalistes ainsi que leurs effets dans la construction de leur jugement sur la véracité du dopage et celle des « pratiques négrières » à l’encontre de jeunes footballeurs. Notre travail souligne l’intérêt d’interroger des journalistes sur leurs façons de mener l’enquête (Dewey, 1993).

International audience; OBJECTIVE: To establish a normative database for isometric strength measured by quantitative muscle testing (QMT) for a French adult population.DESIGN: Measurement of maximal voluntary isometric contraction.SETTING: Four clinical centers involved in neuromuscular disorders.PARTICIPANTS: A total of 315 healthy adults (147 men, 168 women) ages 20 to 80 years.INTERVENTIONS: Not applicable.MAIN OUTCOME MEASURE: Isometric torque values of 14 muscle functions (13 bilaterally and neck).RESULTS: This study led to the development of a French isometric strength normative database for adults measured by QMT. For each muscle function, predictive regression models using age, sex, and weight are proposed. Some methodologic issues concerning strength measurement are discussed.CONCLUSIONS: This database can be used to compute relative deficits in muscle strength for 27 muscle functions and also to estimate composite scores for follow-up of patients either during the natural history of their disease or during a therapeutic trial.

International audience; This paper examines the role of the press in two sports scandals : the wide scale of doping during the “Tour de France 98”, and the illegal employment of African soccer players, aged under-18, by French football clubs. Based on the textual corpora analyzed using the Prospero Software program, we studied how the news media covered these issues, and compared them with the means used by the other actors involved. This led us to study the relationships between the journalists and the latter,and the consequences this had on judgments journalists made about Doping and the existence of a kind of ‘slave trade’ in young soccer players. Our paper highlights the interest of asking journalists how they proceed in conducting their investigation (Dewey, 1993).; De quelques contraintes du processus d'harmonisation des politiques antidopage (enquête) Depuis quelques années, les sciences sociales se sont enfin emparées de l'objet « dopage », dont l'étude est revenue pendant très longtemps au corps médical. La revue de littérature (Mignon, 2002) montre la diversité des approches adoptées, mais à la fois pointe la faible mobilisation des recherches récentes en sociologie politique et morale. Nous souhaitons ici porter l'analyse sur l'organisation de la lutte antidopage.

Article disponible en ligne à l'adresse : http://journal.frontiersin.org/article/10.3389/fpsyg.2015.00237/full; International audience; Since the work of Casasanto (2009), it is now well established that valence and laterality are associated. Participants tend to prefer objects presented on their dominant side over items presented on their non-dominant side, and to place good items on their dominant side and bad items on the other side. Several studies highlight that those associations of valence and laterality are accounted for by the greater motor fluency of the dominant hand and various studies noted that these associations could be reversed depending on the way people interact with their environment. Consistently with the Theory of Event Coding, the aim of this work is to show that the consequences of motor actions could also reverse the associations between valence and laterality. Thus, if participants had to place two animals (one good, one bad) on two supports, one stable (no risk of falling), one unstable (risk of falling), we hypothesized that the good item would be placed on the stable support, regardless of the side where it would be put (i.e., on the dominant or non-dominant side). We expected the opposite for the bad item. The results of two experiments are consistent with this prediction and support the claim that the consequences of motor action bias the hedonic connotation of our dominant side.

International audience; Previous evidence shows that stereotype threat impairs complex motor skills through increased conscious monitoring of task performance. Given that one-step motor skills may not be susceptible to these processes, we examined whether performance on a simple strength task may be reduced under stereotype threat. Forty females and males performed maximum voluntary contractions under stereotypical or nullified-stereotype conditions. Results showed that the velocity of force production within the first milliseconds of the contraction decreased in females when the negative stereotype was induced, whereas maximal force did not change. In males, the stereotype induction only increased maximal force. These findings suggest that stereotype threat may impair motor skills in the absence of explicit monitoring processes, by influencing the planning stage of force production.

This article aims to examine the ways in which researchers respond to a demand for interdisciplinarity and disciplinary excellence. The object of the research is to symmetrically study the efforts for construction of an interdisciplinary recognition, which questions the disciplinary inscription, and the ways of its evaluation. The article develops a pragmatic perspective focusing on the judgment (of disciplinary quality and interdisciplinarity) and its anticipations. For this purpose we analyze a series of interviews, scientific productions, observations and evaluation reports. We have described this process as a willingness to support the one who evaluate the codification of the tests. The fragility of interdisciplinarity consensus makes it impossible to build stable support. It appears difficult to maintain the quality of a research when the tests that this anticipation a priori allows to study are not clearly defined., Faire preuve d'interdisciplinarité Un mot d'ordre, ses interprétations et ses ajustements Résumé Cet article se propose d'examiner les façons par lesquelles les chercheurs répondent à une demande d'interdisciplinarité et d'excellence disciplinaire. L'objet de la recherche consiste à étudier symétriquement les efforts pour construire une reconnaissance interdisciplinaire, qui questionne l'inscription disciplinaire, et les façons de l'évaluer. L'article s'inscrit dans une perspective pragmatique qui prend pour objet le jugement (de la qualité disciplinaire et de l'interdisciplinarité) et ses anticipations. Pour cela nous avons mobilisé un ensemble d'entretiens, de productions scientifiques, d'observations et de rapports d'évaluation. Nous avons décrit ce processus comme une volonté de donner des prises à l'évaluateur qui interroge la codification des épreuves. La fragilité des consensus sur l'interdisciplinarité ne permet pas de construire des appuis stables. Il semble difficile de faire tenir la qualification recherchée si les épreuves que cette anticipation permet a priori d'éluder ne sont pas clairement définies.

International audience; This study investigated the impact of emotion-eliciting images on anticipatory postural adjustments (APAs) associated to forward or backward step initiation. Eighteen healthy young women initiated the two kinds of steps in two conditions: 1) if they judged the image as pleasant or unpleasant, respectively (i.e. congruent condition) and 2) if they judged the image as unpleasant or pleasant, respectively (i.e. incongruent condition). Nine participants performed the congruent condition first while the others performed it in second. The results show that the emotional effect (i.e. the difference between the congruent and incongruent conditions) on APAs associated to forward step only differs according to the axis (anterior-posterior, medio-lateral) that is considered, suggesting a specific emotional component of postural stability.

International audience; The objective of this study was to develop and validate a French-language questionnaire measuring stereotypes related to exercise in cancer patients: The Cancer Exercise Stereotypes Scale (CESS). Four successive steps were carried out with 806 participants. First, a preliminary version was developed on the basis of the relevant literature and qualitative interviews. A test of clarity then led to the reformulation of six of the 30 items. Second, based on the modification indices of the first confirmatory factorial analysis, 11 of the 30 initial items were deleted. A new factorial structure analysis showed a good fit and validated a 19-item instrument with five subscales. Third, the stability of the instrument was tested over time. Last, tests of construct validity were conducted to examine convergent validity and discriminant validity. The French-language CESS appears to have good psychometric qualities and can be used to test theoretical tenets and inform intervention strategies on ways to foster exercise in cancer patients.

The purpose of this study was to examine the effects of 2 braking forces (8.7 and 11% of body mass, BM) on Wingate test performance, peak lactate ([La]pk), peak heart rate (HRpk), and rate of perceived exertion (RPE). Sixteen male physical education students (age: 22.7 +/- 1.3 years, height: 1.81 +/- 0.07 m, BM: 74.3 +/- 9.6 kg) performed, in a randomized order, 2 Wingate tests at 8.7% BM and 2 Wingate tests at 11% BM on a Monark cycle ergometer on 4 separate sessions. The results showed that the reliability level of mechanical measures was not affected by the braking force and was relatively similar for each variable in both braking forces (0.886 < ICC < 0.985). In addition, peak power, mean power, fatigue slope, and RPE were significantly higher (8.2, 7.0, 11.9, and 4.1%, respectively, all < 0.05) using a braking force of 11% BM compared with 8.7% BM, whereas there was no significant effect of braking force on [La]pk and HRpk. In conclusion, the results of this study suggested that the reliability of the Wingate test does not depend on the used load, and a braking force of 11% BM is more optimal for power output during Wingate test in active adults.

The present investigation verified that strength is improved by a training programme consisting of repetitions of maximal isometric voluntary co-contractions without increasing co-activations during contractions against external resistances. Ten participants performed 12 training sessions (four sets of 6 × 4 second maximal isometric co-contraction of the elbow flexor and extensors, 3 days a week for 4 weeks). Surface electromyograms of triceps and biceps brachii were collected during maximal voluntary isometric elbow flexion and extension against a force transducer. Maximal voluntary isometric force increased significantly after training, by 13.8 ± 6.0% (extension) and 9.6 ± 9.5% (flexion), but the observed increases in EMG of agonist muscles during maximal voluntary contraction were not significant. No significant changes in the levels of co-activation of the elbow flexors and extensors were observed. No significant change was observed for all the parameters in a control group of ten participants. These results indicated that the strength improvements after co-contraction training occur without increases in co-activation level.

International audience; This study aims to demonstrate the effect of action fluency on emotional evaluation, specifically to show that neutral words can be evaluated positively or negatively depending on motor activity and evaluative setting. Right-handers naturally tend to associate positive (negative) valence to the right (left) part of space (Casasanto, 2009). We extend these associations to lateralized behaviors by studying the combined effect of motor fluency of lateral arm movements and the evaluative scale on the subjective evaluation of neutral words. Three experiments evidenced that, for right-handers, the realization of fluent rightward arm movements and the use of an evaluative scale congruent with their valence/laterality associations (left negative, right positive) led to a positive evaluation of neutral words, while non-fluent leftward movements and an incongruent scale led to a negative evaluation. This study demonstrates that emotion–action associations are experience-based, and influenced by functional and situational constraints.

The aim of this study was to test the influence of 3 different horizontal distances between the blocks (bunched, medium and elongated) on the velocity of the centre of mass (V CM ) and the kinetic energy (KE) of the body segments and of the whole body. 9 well-trained sprinters performed 4 maximal 10 m sprints. An optoelectronic Motion Analysis ® system (12 digital cameras 250 Hz) was used to collect the 3D trajectories of 63 markers during the starting block phase. The results demonstrated that the elongated start, compared to the bunched or medium start, induced an increase of V CM at block clearing (2.89 ± 0.13; 2.76 ± 0.11; 2.84 ± 0.14 m.s − 1 ) and a decrease of the performance at 5 and 10 m. Both results were explained by a greater pushing time on the blocks in the elongated condition. During the starting block phase, the KE of the whole body was greater in the elongated start (324.3 ± 48.0 J vs. 317.4 ± 57.2 J, bunched and 302.1 ± 53.2 J, medium). This greater KE of the whole body was mainly explained by the KE of the head-trunk segments. Thus, to improve the effi ciency of the starting block phase, the athlete must produce greater KE of the head and trunk segments in the shortest time.

International audience; We provide a mathematical study of a model of energy metabolism and hemodynamics of glioma allowing a better understanding of metabolic modifications leading to anaplastic transformation from low grade glioma. This mathematical analysis allows ultimately to unveil the solution to a viability problem which seems quite pertinent for applications to medecine.

International audience; Muscle activation during self-resistance exercises was studied in 18 subjects performing (a) maximal unilateral isometric cocontractions of flexor and extensor muscles of the right elbow (UNI); (b) bilateral exercises consisting of maximal isometric extensions of the right elbow against the left elbow flexors (BiExt) and maximal isometric flexion of the right elbow against the left elbow extensors (BiFlex). Force production by the biceps brachii (BB), brachioradialis (BR), and triceps brachii (TB) during UNI, BiFlex, and BiExt were estimated by comparing the integrated surface electromyograms (iEMG) of BB, BR, and TB during UNI, BiExt, and BiFlex with the individual iEMG-force relationship determined from isometric contractions at 30, 60, and 100% maximal voluntary contraction during elbow flexion (MVCflex) or extension (MVCext) against a force transducer. During BiFlex for BB or BR and BiExt for TB, the values (mean ± SE) of BB-iEMG, BR-iEMG, and TB-iEMG were 74.0 ± 4.5, 76.6 ± 5.7, and 84.4 ± 4.5% iEMG at MVC (% iEMGmax). The forces were 86.0 ± 3.7% TB-Forcemax during BiExt, 74.1 ± 3.6% BB-Forcemax and 71.8 ± 4.0% BR-Forcemax during BiFlex. During UNI, BB-iEMG, BR-iEMG, and TB-iEMG were 59.9 ± 4.6, 53.4 ± 4.0, and 66.3 ± 4.7% iEMGmax, respectively. The forces during UNI (70.4 ± 4.0% TB-Forcemax, 60.4 ± 4.3% BB-Forcemax, and 49.2 ± 3.1% BR-Forcemax) were significantly lower than those during bilateral exercises. A 2-way analysis of variance (Muscle and Exercise) indicated that the effects of Muscle and Exercise upon % iEMGmax were significant (p < 0.05; p < 0.001, respectively). In conclusion, bilateral opposition exercises should be more effective in developing strength than cocontraction exercises, which correspond to a moderate activation level even for weak agonist muscle groups.

International audience; The purpose of this investigation was to assess the effects of training and tapering at the same time of the day on the diurnal variations of short exercise performances. Thirty-one physically active men underwent 12 weeks of lower-extremity resistance training and 2 weeks of tapering. These subjects were matched and randomly assigned to a morning training group (MTG, training times 0700-0800 hours, n = 10), an evening training group (ETG, training times 1700-1800 hours, n = 11), and a control group (CG, completed all tests but did not train, n = 10). Muscular strength and power testing was conducted before (T0) and after 12 weeks of training (T1) and after 2 weeks of tapering (T2) in the morning (0700-0800 hours) and in the evening (1700-1800 hours). All morning and evening tests were performed in separate sessions (minimum interval = 36 hours) in a randomized design. In T0, the oral temperature and performances during the Wingate, vertical jump (squat jump and countermovement jump), and maximal voluntary contraction tests were higher in the evening than in the morning for all the groups. In T1, these diurnal variations were blunted in the MTG and persisted in the ETG and CG. In T2, the 2 weeks of tapering resulted in further time of day-specific adaptations and increases in short-term maximal performances. However, there was no significant difference in the relative increase between the MTG and the ETG after both training and tapering. From a practical point of view, if the time of competition is known, training and tapering sessions before a major competition must be conducted at the same time of the day at which one's critical performance is programmed. Moreover, if the time of the competition is not known, a tapering phase after resistance training program could be performed at any time of the day with the same benefit.