Knee extension strength in obese and nonobese male adolescents

The aim of the present study was to compare “absolute” and “relative” knee extension strength between obese and nonobese adolescents. Ten nonobese and 12 severely obese adolescent boys of similar chronological age, maturity status, and height were compared. Total body and regional soft tissue composition were determined using dual-energy X-ray absorptiometry (DXA). Knee extensors maximum voluntary contraction (MVC) torque was measured using an isometric dynamometer at a knee angle of 60° (0° is full extension). Absolute MVC torque was significantly higher in obese adolescents than in controls. However, although MVC torque expressed per unit of body mass was found to be significantly lower in obese adolescent boys, no significant difference in MVC torque was found between groups when normalized to fat-free mass. Conversely, when correcting for thigh lean mass and estimated thigh muscle mass, MVC torque was significantly higher in the obese group (17.9% and 22.2%, respectively; P <0.05). To conclude, our sample of obese adolescent boys had higher absolute and relative knee extension strength than our nonobese controls. However, further studies are required to ascertain whether or not relative strength, measured with more accurate in vivo methods such as magnetic resonance imaging, is higher in obese adolescents than in nonobese controls

Effects of a short residential thermal spa program to prevent work-related stress/burnout on stress biomarkers: The thermstress proof of concept study

Objective Work-related stress is a public health issue. Stress has multiple physical and psychological consequences, the most serious of which are increased mortality and cardiovascular morbidity. The ThermStress protocol was designed to offer a short residential thermal spa program for work-related stress prevention that is compatible with a professional context. Methods Participants will be 56 male and female workers aged 18 years or above. All participants will undergo a 6-day residential spa program comprising psychological intervention, physical activity, thermal spa treatment, health education, eating disorder therapy and a follow-up. On six occasions, participants’ heart rate variability, cardiac remodelling and function, electrodermal activity, blood markers, anthropometry and body composition, psychology and quality of life will be measured using questionnaires and bone parameters. Results This study protocol reports the planned and ongoing research for this intervention. Discussion The ThermStress protocol has been approved by an institutional ethics committee (ANSM: 2016 A02082 49). It is expected that this proof of concept study will highlight the effect of a short-term specific residential thermal spa program on the prevention of occupational burnout and work-related stress. The findings will be disseminated at several research conferences and in published articles in peer-reviewed journals. Trial Registration: ClinicalTrials.gov (NCT 03536624, 24/05/2018

Etude longitudinale du developpement bioenergetique de l'enfant au cours de la puberte: influence de l'entrainement

Available from INIST (FR), Document Supply Service, under shelf-number : TD 20475 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Enfant et exercice musculaire (utilisation des substrats énergétiques)

L'objectif était dans un 1er temps de mettre en évidence le lien entre la sévérité de l'insulino-résistance et la localisation du tissu adipeux au niveau abdominal ou périphérique à partir de mesures réalisées par absorptiométrie biphotonique à rayons X chez de jeunes obèses. Le développement excessif du tissu adipeux résultant d'une balance lipidique positive, nous avons étudier les effets du délai écoulé entre une prise alimentaire standardisée (3h vs 1h) et l'exercice physique sur l'utilisation des substrats énergétiques au cours d'un exercice d'intensité modérée tels que ceux habituellement préconisé dans le traitement de l'obésité et de la période de récupération post-exercice. Nous avons observé que la localisation abdominale plutôt que périphérique du tissu adipeux était associée avec une augmentation de l'insulino-résistance. Les résultats ont mis en évidence qu'un délai de 3 heures entre la prise alimentaire et l'exercice physique ne permettait pas d'accroître l'oxydation des lipides lors de l'exercice et de la récupération post exercice chez les enfants obèses ou minces par rapport à un exercice identique réalisé après un délai de 1 heure. De plus, bien que des différences apparaissent au niveau de la biodisponibilité des substrats énergétiques entre enfants obèses et minces, il n'apparait pas d'altération de l'utilisation des substrats au cours de la période postprandiale liée à l'obésité. Enfin, l'oxydation lipidique contribue faiblement à la dépense énergétique en période post prandiale lors d'un exercice à une intensité ayant préalablement été déterminée comme associée à l'oxydation maximale des lipides. En conclusion, ces études indiquent des altérations métaboliques chez les enfants obèses qui ne sont cependant pas associées à une différence d'utilisation des substrats énergétiques lors de l'exercice par rapport à des enfants minces et non entraînés.The prevalence of childhood obesity, especially at the abdominal level, a increased dramatically over the last decades. The aim of this thesis was to investigate the association between insulin resistance and an index of body fat distribution based on Dual energy X-ray absorptiometry measurements in obese youth. Due to its effects on energy expenditure and muscle oxidative ability, physical activity is advocated in the treatment of the obesity. As obesity is primarily the consequence of a positive energy balance and a positive fat balance, we aimed at studying the effects of time interval between food intake and exercise on rates offat and carbohydrate oxidation during a moderate intensity exercise as generally recommended in the treatment of obesity and the following post-exercise recovery period. We have observed that abdominal rather than peripheral localization of adipose tissue was associated with an increase in insulin resistance. Then, our results have shown that a 3.00 hours time interval between food intake and exercise did not elicit an increase in fat oxidation compared to a 1.00 hour time interval whether children are obese or not. Even though, substrates bioavailability was altered in obese children compared to lean children at the end of exercise, rates of fat and carbohydrate oxidation were not significantly different in obese and lean children during the post-exercise period. To conclude, our results showed that in the postprandial state fat oxidation contributes weakly to energy expenditure during an exercise performed at an intensity which has previously been associated with maximal fat oxidation. To conclude, these studies have shown that metabolic alterations in obese children which are not associated with differences in substrates utilization when these children are compared to lean and untrained children.CLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF

Activité physique et condition physique de la personne agée (effets de l'entraînement et du désentraînement sur la composition corporelle, la performance musculaire et l'aptitude aérobie)

CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocCLERMONT FD-UBP-UFR STAPS (630142215) / SudocSudocFranceF

EVOLUTION DE LA PUISSANCE MAXIMALE ET EQUILIBRE ACIDO-BASIQUE SANGUIN AU COURS D'UN EXERCICE INTERMITTENT BREF ET INTENSE (INFLUENCE DE L'AGE ET DE LA DUREE DE RECUPERATION (DOCTORAT))

CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUM (751062103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Measuring levels of muscle fatigue in spastic cerebral palsy

International audienc

Activité physique et sédentarité : une synthèse vulgarisée des nouvelles recommandations

International audienceLes recommandations françaises sur la pratique d'activité physique et la réduction de la sédentarité ont été actualisées en février 2016, dans un rapport d'expertise collective et un avis de l'Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (Anses). Elles ont évolué sur plusieurs points : la distinction entre l'activité physique et la sédentarité, la précision des types d'activités physiques à pratiquer et la spécificité des recommandations pour les enfants ; les adolescents ; les adultes ; femmes enceintes, en période de post-partum, ménopausées ; les personnes âgées de 65 ans et plus ; et les personnes ayant une limitation fonctionnelle d'activité

The Effects of Imposed Sedentary Behavior and Exercise on Energy Intake in Adolescents With Obesity

Objective: Exercise has been shown to decrease subsequent energy intake, without modification of appetite, in adolescents who are obese. This study compared the impact of acute exercise with imposed sedentary behaviors on the daily nutritional adaptations and energy balance of youths with obesity. Methods: Body composition and maximal oxygen uptake were assessed in 10 12- to 15-year-old adolescents with obesity. Energy consumption, appetite, and energy expenditure were assessed during 3 experimental sessions: (1) exercise session (EX), (2) bed rest session (BR), and (3) control session (CON). Results: Total and morning energy expenditures were significantly higher during EX compared to CON and BR sessions (p < .001), and no differences were found during the afternoon energy expenditure between conditions (BR: 1056.5 +/- 121.5; CON: 1185.7 +/- 173; EX: 996.1 +/- 153.4 Kcal). Total energy intake was significantly reduced on EX (p <.001). Dinner energy intake was significantly reduced during EX (491.65 +/- 75.74 Kcal) and CON (666.55 +/- 152.09 Kcal) compared with BR (818.87 +/- 122.97 Kcal) (p <.001). Appetite was not affected. Conclusion: Whereas intense exercise reduces daily energy balance in adolescents with obesity by mainly affecting ad libitum dinner energy consumption, imposed sedentary behaviors lead to increased energy intake and then positive energy balance. The impact of exercise or imposed sedentary behaviors on the energy balance of adolescents with obesity is not only related to the exercise-induced energy expenditure, but also to their energy intake

Why does walking economy improve after weight loss in obese adolescents?

International audiencePURPOSE: This study tested the hypothesis that the increase in walking economy (i.e., decrease in net metabolic rate per kilogram) after weight loss in obese adolescents is induced by a lower metabolic rate required to support the lower body weight and maintain balance during walking. METHODS: Sixteen obese adolescent boys and girls were tested before and after a weight reduction program. Body composition and oxygen uptake while standing and walking at four preset speeds (0.75, 1, 1.25, and 1.5 m·s⁻¹) and at the preferred speed were quantified. Net metabolic rate and gross metabolic cost of walking-versus-speed relationships were determined. A three-compartment model was used to distinguish the respective parts of the metabolic rate associated with standing (compartment 1), maintaining balance and supporting body weight during walking (compartment 2), and muscle contractions required to move the center of mass and limbs (compartment 3). RESULTS: Standing metabolic rate per kilogram (compartment 1) significantly increased after weight loss, whereas net metabolic rate per kilogram during walking decreased by 9% on average across speeds. Consequently, the gross metabolic cost of walking per unit of distance-versus-speed relationship and hence preferred walking speeds did not change with weight loss. Compartment 2 of the model was significantly lower after weight loss, whereas compartment 3 did not change. CONCLUSIONS: The model showed that the improvement in walking economy after weight loss in obese adolescents was likely related to the lower metabolic rate of the isometric muscular contractions required to support the lower body weight and maintain balance during walking. Contrastingly, the part of the total metabolic rate associated with muscle contractions required to move the center of mass and limbs did not seem to be related to the improvement in walking economy in weight-reduced individuals