Les programmes d'activité physique et les régimes alimentaires sont communément utilisés pour favoriser, en réduisant la balance énergétique, la perte de poids des patients en surpoids ou obèses. De tels programmes pâtissent d'une faible adhésion de la part des patients et d'un taux élevé d'abandons dû aux difficultés que rencontrent les individus à concilier exercice et restriction d'énergie. Il a été suggéré que l'exercice physique était un moyen potentiel pour réguler l'apport indirect d'énergie, ce qui pourrait s'avérer intéressant sur le plan du traitement de l'obésité.L'impact que l'exercice pouvait avoir sur la balance énergétique subséquente (apport et dépense énergétiques), ainsi que sur l'appétit, a été principalement étudié dans le cas d'adultes de faible corpulence, mais peu de données sont disponibles pour les populations d'individus obèses, et tout particulièrement pour les enfants qui souffrent d'obésité.Le but premier de ce travail était donc de déterminer si un exercice réalisé à un moment précis pouvait par la suite affecter la balance énergétique ainsi que l'appétit des adolescents obèses (Etude I). Par la suite, nous avons étudié l'importance que pouvait avoir l'intensité de l'exercice prescrit (intensité faible VS intensité élevée) sur les modifications de la balance énergétique et de l'exercice (Etude II). Les résultats démontrent qu'un exercice intensif (>70%VO2 max), exécuté en fin de matinée, favorise une balance énergétique réduite en diminuant principalement l'apport d'énergie. Cependant, les données restent contradictoires concernant l'apport de macronutriments après l'exercice, et il est nécessaire d'approfondir les recherches. En ce qui concerne les adaptations de la balance énergétique et de l'appétit après l'exercice, aucune différence n'avait été observée en fonction du sexe des individus. Les adaptations observées en termes d'apport énergétique n'étaient pas accompagnées de changements en termes de sensation de faim, ce qui laisse à penser que les adolescents obèses ne risquent pas de ressentir de la frustration.En 24h, la balance énergétique des adolescents obèses peut être réduite grâce à la fois à une dépense énergétique élevée et à un apport d'énergie réduit, quand un exercice intensif est réalisé en fin de matinée. Etant donné que de tels résultats découlent d'actes à caractère chroniques, il est nécessaire de les interroger, afin de savoir si l'exercice intensif peut s'avérer être un véritable outil permettant d'induire sur le long terme une réduction de la balance énergétique (en affectant à la fois la dépense et l'apport énergétique), et par la suite une perte de poids. / Physical activity programs and dietary restrictions are commonly used to favor weight-loss in overweight and obese patients, by reducing energy balance. Such programs suffer of a low adherence and high drop-out due to the difficulties met by patients to concomitantly support exercise and energy restriction. Physical exercise has been proposed as a potential indirect energy intake modulator, which could be interesting in terms of obesity treatment. The impact of exercise on subsequent energy balance (intake and expenditure) and appetite has been mainly questioned among lean adults but few data are available in obese populations, particularly pediatrics. The first aim of this work was then to determine whether or not an acute bout of exercise could affect subsequent energy balance and appetite in obese adolescents (STUDY I). Then the importance of the prescribed exercise intensity (Low vs High intensity) on those energy balance and appetite modifications has been investigated (STUDY II). The results demonstrate that an intensive exercise (>70%VO2max) realized by the end of the morning favors a reduced energy balance by mainly decreasing energy intake. The induced energy intake decrease was observed within minutes after the exercise (30 minutes, lunch time), with the onset being experienced about 7 hours after, during dinner time. Data remain however contradictive concerning the post exercise macronutrient intake, and further investigations are required. No gender difference was observed in terms of post exercise energy balance and appetite adaptations. The observed energy intake adaptations were not accompanied by appetite sensation modifications, suggesting that obese adolescents are not at risk for food frustration. Within 24-h, obese adolescents’ energy balance can be reduced thanks to both elevated energy expenditure and decreased energy intake when an intensive exercise is performed by the end of the morning. Such results need to be questioned as part of chronic interventions to know whether or not intensive exercise can provide a great tool to induced long term energy balance reduction (by dually affecting energy expenditure and intake) and then weight loss.

Endocannabinoid and immune system alterations at moderate (18 m/min) and endurance (32 m/min) exercise intensities were assessed and compared to controls. Rats were exercised for 60 minutes/day, 5 days/week for 16 weeks. Immune effector cell proportions (T cell subtypes, B cells, NK cells, and neutrophils) and endocannabinoid serum levels were determined. Anandamide (ANA) and 2 arachidonyl-glycerol (2-AG) serum levels increased with endurance type of exercise. mRNA expression of the CB1 receptor increased together with ANA in the same group. Apoptotic index increased while immune effector cells responded divergently. B lymphocyte percentage decreased while T lymphocyte and NK cell percentage increased in blood. CD8+ subtypes increased whereas CD11b+ cell and CD25+ cell numbers decreased in the spleen in the endurance type of exercise group. Rats were grouped as the control, the endurance type of exercise, the AM281 (CB1 receptor antagonist) and the AM281+AM630 (CB2 receptor antagonist) groups in the second part of the study. Flow cytometry and microarray analyses of the spleen and the thymus were conducted. Endurance type of exercise associated significantly to immunological changes particularly to that of the T lymphocytes. T lymphocytes increased whereas cytolytic T lymphocytes decreased in blood. T cell and double positive T cell percentages significantly increased in the spleen. Activated T cells and NK like T cells furthermore decreased in the spleen. AM281 and/or AM630 could partially reverse the effect of exercise in blood but not in the spleen. Alterations in the thymus were not observed. Exercise altered 302 genes, some of them related with the immune system. Up-regulation of heat-shock protein coding genes was the most significant ones.

Cell-derived microvesicles (MVs) are naturally released into the human circulation and an increase in the concentration of certain MV populations have been observed after exercise. However, the MV appearance dynamics, the exercise-related stimuli that induce their formation and physiological relevance are poorly understood. Hence, the overall objectives of this thesis were to: 1) characterise the circulating platelet (PMV) and endothelial-derived MVs (EMVs) responses during exercise and recovery, as well as their arteriovenous dynamics, 2) investigate the potential role of haemodynamic forces on MVs formation in vivo by vascular shear stress manipulations, and 3) explore the putative proliferative, chemotactic and angiogenic potential of exercise-derived MVs upon human vascular endothelial cells in vitro. Chapter 5 of this thesis describes the time-course of MV appearance in response to prolonged cycling, and demonstrates that intravascular [PMV] increases during and after exercise performed in the heavy intensity domain, whereas [EMV] remains unaltered. Moreover, [PMV] during exercise was related to estimates of vascular shear stress and plasma noradrenaline levels. Results from chapter 6 revealed that PMVs increased in the arterial circulation during passive heat stress, and in the arterial as well as venous circulation during short duration very heavy exercise engaging either a large or small muscle mass. The increases in [PMV] were not directly linked to local changes in vascular shear stress through heat stress and exercise, indicating a systemic PMV response. Finally, chapter 7 revealed that exercise-derived MVs supported endothelial proliferation and migration, while displaying pro-angiogenic potential in vitro. In conclusion, results of this thesis provide original information about MV dynamics, by demonstrating that PMV increase systemically in the circulation not only after but during exercise involving a small and large muscle mass. This MV response seems to be modulated by exercise intensity, and is only partially linked to levels of vascular shear stress. Moreover, circulating MVs produced during exercise present stimulatory angiogenic and mitogenic effects upon endothelial cells in vitro, suggesting a novel potential link between vascular adaptation and exercise training.

Introduction: Sport scientist and strength coaches use resistance training to increase athletic performance and muscle hypertrophy. Improving muscular strength is the most essential task for these scientists, however, how best to identify weakness has yet to be established. The popularity of velocity-based resistance training has recently increased as a method to prescribe resistance training intensity, therefore, the purpose of the study was to identify the characteristics of bench press concentric velocity. It is hypothesized that the velocity output will decrease during the change from the 75% relative load of the 1RM to the 85% relative load of 1RM. It is believed that there will be a greater output of velocity during the 75% set than the 85% set. Methods: Nine female collegiate athletes (18-21 yrs), participated in this study. PUSH™ bands were used to measure barbell velocity during the bench press exercise. Each female was expected to preform 3 sets of 5 repetitions (3x5) at an intensity of 75% and 85% of their 1 repetition maximum (1RM). Only data from repetition 2-4 were used for analysis. Results: The results drawn from data collected supported our hypothesis showing a decrease in velocity among the 85% 1RM test when compared to the 75% 1RM test group. Comparisons were drawn using a t-Test table comprised of PUSH™ Band data. Conclusion: The results supported the hypothesis that this type of technology can identify the load specific velocity to help strength coaches to identify the optimal resistance for certain training program and goals by using collected data with the PUSH™ Band to identify weakness in strength and/or endurance.

No description available.

The purpose of the present investigation was to identify the exercise intensity of netball match play in order to assist in the development of a Netball Intermittent Activity Test (NIAT). A further aim was to assess the criterion validity and the test-retest reliability of the NIAT. Eleven female netball players (21.4 ± 3.1 years, 1.73 ± 0.06 m, 69.3 ± 5.3 kg and 48.4 ± 4.9 ml•kg-1•min–1 mean ± SD, age, height, body mass and VO2max, respectively) volunteered to participate in the study. Heart rate data was recorded for all participants from at least two full 60 minute games during Premier Club competition. Individual maximum heart rate values were acquired for all subjects from the performance of the Multistage Fitness Test, and used to transform heart rate recordings into percent maximum heart rate (%HRmax). Patterns in %HRmax were used to indicate positional grouping when developing the NIAT from time motion analysis data. Subjects performed two trials of the NIAT separated by at least seven days. Physiological and performance markers were measured systematically throughout the NIAT. Exercise intensity as denoted by %HRmax significantly decreased from the first half of match play to the second half (90.4 ± 2.7% v 88.3 ± 2.8%; p<0.05). Significant differences (p<0.05) were observed between positional groups and led to the grouping of Defence (D), Centre Court (CC), and Attack (A) players for NIAT performance. Comparisons of %HRmax between match play and NIAT performance indicated that the NIAT had good criterion validity for D (match Mdn = 92.52% vs. NIAT Mdn = 86.27%, p>0.05) and A (match Mdn = 86.95% vs. NIAT Mdn = 82.93%, p>0.05) players, but that %HRmax during the NIAT (Mdn = 79.70%) was significantly lower than match play (Mdn = 89.70%) for CC group (p<0.05). Measures of 5 m sprint performance (1.27 ± 0.06 s v 1.25 ± 0.06 s; p>0.05; r=0.66, p<0.001), vertical jump height (29.12 ± 4.17 cm v 28.82 ± 3.60 cm; p>0.05; r=0.91, p<0.001), circuit time (107.49 ± 3.22 s v 107.89 ± 4.27 s; p>0.05; r=0.72, p>0.001) and %HRmax (82.56 ± 4.66% v 81.03 ± 4.13%; p>0.05; r=0.82, p<0.001) for NIAT1 vs. NIAT2 indicated good test-retest reliability. These data suggest that netball players experience a reduction in exercise intensity over the duration of a game, with exercise intensity being related to on-court position. Whilst the NIAT appears to be a repeatable activity pattern, it is not a good simulation of physiological strain for all positional groups. More work is required in order to create a netball simulation that is both reliable and valid for all players.

This paper develops a computer spreadsheet framework and model for estimating the individual benefits and costs of exercise for long run health. The biological costs and benefits rest on solid production functions between exercise intensity levels, fitness levels, and two key indices of long run health outputs—probability of all cause mortality and an index of health care costs. The less certain monetary estimates of those costs and benefits come from reviews of the key literature. The resulting model of individual exercise costs and benefits provides a basis for individual long run health planning plus cost effective and cost benefit analysis of different exercise strategies. The latter, which uses the implicit value of life, may provide insights to the lack of consistent exercise and strategies to increase it.

Purpose: Effects of simultaneous vibration-stretching on flexibility and explosive strength in competitive female gymnasts were examined. Methods: Twenty-two female athletes (age = 11.3 ± 2.6 yr; body mass = 35.3 ± 11.6 kg; competitive levels = 3-9) composed the simultaneous vibration-stretching (VS) group, which performed both tests. Flexibility testing control groups were stretching-only (SF) (N = 7) and vibration-only (VF) (N = 8). Explosive strength-control groups were stretching-only (SES) (N = 8) and vibration-only (VES) (N = 7). Vibration (30 Hz, 2-mm displacement) was applied to four sites, four times for 10 s, with 5 s of rest in between. Right and left forward-split (RFS and LFS) flexibility was measured by the distance between the ground and the anterior suprailiac spine. A force plate (sampling rate, 1000 Hz) recorded countermovement and static jump characteristics. Explosive strength variables included flight time, jump height, peak force, instantaneous forces, and rates of force development. Data were analyzed using Bonferroni adjusted paired t-tests. Results: VS had statistically increased flexibility (P) and large effect sizes (d) in both the RFS (P = 1.28 × 10−7, d = 0.67) and LFS (P = 2.35 × 10−7, d = 0.72). VS had statistically different results of favored (FL) (P = 4.67 × 10−8, d= 0.78) and nonfavored (NFL) (P = 7.97 × 10−10, d = 0.65) legs. VF resulted in statistical increases in flexibility and medium d on RFS (P = 6.98 × 10−3, d = 0.25) and statistically increased flexibility on VF NFL flexibility (P = 0.002, d = 0.31). SF had no statistical difference between measures and small d. For explosive strength, there were no statistical differences in variables in the VS, SES, and VES for the pre- versus posttreatment tests. Conclusions: Simultaneous vibration and stretching may greatly increase flexibility while not altering explosive strength.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-10-04T18:26:19Z No. of bitstreams: 1 otaviorodriguesdepaula.pdf: 426345 bytes, checksum: 18130a964ae3eb108408c82a90006fbb (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-10-05T10:52:25Z (GMT) No. of bitstreams: 1 otaviorodriguesdepaula.pdf: 426345 bytes, checksum: 18130a964ae3eb108408c82a90006fbb (MD5) / Made available in DSpace on 2016-10-05T10:52:25Z (GMT). No. of bitstreams: 1 otaviorodriguesdepaula.pdf: 426345 bytes, checksum: 18130a964ae3eb108408c82a90006fbb (MD5) Previous issue date: 2010-03-05 / A Dança Esportiva em Cadeira de Rodas (DECR) é uma modalidade esportiva adaptada da dança de salão praticada no Brasil desde 2001, porém, não há estudos que abordem as respostas fisiológicas ao esforço que os atletas/dançarinos se submetem numa competição de DECR. Objetivos: descrever os valores de freqüência cardíaca (FC) e os níveis das concentrações de lactato [La] sanguíneo, verificar o comportamento da curva da freqüência cardíaca dos dançarinos cadeirantes durante uma competição de DECR, comparar a carga física entre as rodadas e a resposta cardíaca específica entre as danças Samba, Rumba e Jive. E por último, comparar a FCMpico (freqüência cardíaca máxima de pico) obtida pelos atletas na competição, frente a FCMcal (freqüência cardíaca máxima calculada) prevista para a idade. Métodos: Participaram deste estudo 9 (nove) atletas cadeirantes com deficiência (quatro com lesão medular, três com seqüela de poliomielite e um com espinha bífida), sendo quatro homens e cinco mulheres, com média de 34,6±10,5 anos de idade, 53,7±9 kg de massa corporal, 4,1±2,4 anos de prática e que competiram durante o VII Campeonato Brasileiro de DECR. Para o registro da FC utilizou-se o conjunto de cardiofrequencímetros durante toda a competição, já para a medidas das [La] foram realizadas cinco a representação gráfica da curva da FC demonstrou-se compatível com atividade física intermitente, a média da carga física das rodadas foi de 89,9%FCpico não havendo diferença significativa entre as mesmas. Em relação aos estilos de dança, houve diferença significativa de intensidade, sendo o Jive mais intenso (p≥0,05) do que o Samba e a Rumba não havendo diferença entre essas duas. A média da FCMpico (189 bpm) foi maior (p≥0,05) do que a média da FCMcal (165,3 bpm). Em relação aos níveis de [La] a maioria dos atletas avaliados atingiu valores de pico entre 4,2 e 6,2 mM. Conclusão: a DECR é uma modalidade com características intermitentes, a média de intensidade durante as rodadas é compatível com uma atividade de alta intensidade e muito provavelmente os atletas atingem a FCM durante a competição. / The Wheelchair Sport Dance (WSD) it is an adapted sport modality of the ballroom dance practiced in Brazil since 2001, however, no there are studies that approach the physiologic answers to the effort that the athletes/dancers submit in a competition of WSD. Purpose: to describe the values of heart rate (HR) and the levels of the lactate concentrations [La] sanguine, to verify the behavior of the curve of the HR of the dancers wheelchairs during a competition of WSD, to compare the physical load between the rounds and the specific heart answer among the dances Samba, Rumba and Jive. It is last, to compare HRpeak (heart rate peak maxim) obtained by the athletes in the competition, front HRMcal (maximum heart rate calculated) foreseen for the age. Methods: They participated in this study 9 (nine) athletes wheelchairs with disabled (four with spinal cord injury, three with poliomyelitis sequel and one with bifid spine), being four men and five women, with average 34,6±10,5 years , 53,7±9 kg of body mass, 4,1±2,4 years of practice and that competed during the VII Brazilian Championship of WSD. For the registration of HR the Polar Team Systeam was used during all the competition, already for to measured of the [La] five were accomplished. The graphic representation of the curve of HR was demonstrated compatible with intermittent physical activity, the average of the physical load of the rounds was of 89,9%HRpeak not having significant difference among the same ones. In relation to the dance styles, there was significant difference of intensity, being most intense Jive than the Samba and the Rumba not having difference among those two. The average of HRMpeak (189 bpm) it was larger (p?0,05) than the average of HRMcal (165,3 bpm). In relation to the levels of [La] most of the appraised athletes reached pick values between 4,2 and 6,2 mM. Conclusion: WSD is a modality with intermittent characteristics, the average intensity during the rounds is compatible with an activity of high intensity and very probably the athletes reach HRMduring the competition.

L’accident vasculaire cérébral (AVC) est un problème majeur de santé publique car les troubles fonctionnels associés ont des répercussions délétères sur la qualité de vie des patients. Deux axes de recherche portant sur l’ischémie cérébrale chez le rat sont abordés. Pour le premier, il s’agira d’étudier les modifications de la régulation des réflexes somatiques qui peuvent contribuer à expliquer en partie les déficits fonctionnels. Nos résultats montrent une fatigue précoce au cours d’un exercice isométrique du triceps brachial et une perturbation de l’inhibition du réflexe-H post-exercice. Nous avons précisé que la perturbation de l’activité des voies réflexes est associée à une modification de l’action inhibitrice des afférences musculaires des groupes III et IV pouvant expliquer la fatigue précoce observée. L’axe 2 concerne l’optimisation de l’entrainement d’endurance, stratégie prometteuse pour traiter les déficits. L’objectif est de définir la stratégie d’endurance la plus appropriée en nous focalisant sur l’intensité de l’exercice. Pour cela, les effets des exercices d’intensité modérée (classiquement recommandés) ont été confrontés avec ceux des exercices intermittents de haute intensité (HIT) en analysant la récupération fonctionnelle et la neuroplasticité cérébrale. Nos résultats montrent que l’intensité de travail, déterminée à partir du seuil lactique, est un paramètre crucial car les HIT se révèlent être plus efficaces en termes de récupération de la force, d’aptitude aérobie et de neuroplasticité. Ces travaux ouvrent de nombreuses perspectives où ces 2 axes pourraient se rejoindre en approfondissant les effets des HIT au niveau cérébral et spinal. / Stroke is a major public health issue because associated functional disorders have detrimental impacts on life quality and independence of patients as well as on economic state. This thesis work is focused on 2-research axis concerning cerebral ischemia in rat. The aim of the first axis is to study plasticity at spinal level by investigating the alteration of somatic reflex regulation that could contribute to partially explain functional deficits. Ours results show early fatigue of triceps brachii during an isometric contraction and H-reflex inhibition perturbation post-exercise. We also observed that the disturbance of reflex pathway activity is associated with a decrease of the inhibitory effect induced by muscular metabosensitive afferents that might explain early fatigue and observed functional deficits. The second axis treats about endurance training that is a promising strategy to reduce stroke-induced disorders but remains to improve. In that way, the purpose is to determine which endurance strategy is the most suitable by focusing on exercise intensity. In order to ensure this, the effects of moderate intensity exercise (classically recommended) have been compared to high intensity interval training (HIT) by analysing the functional recovery and cerebral neuroplasticity. Our data show that work intensity, based on lactic threshold, is a critical parameter. Indeed, HIT is more effective for increasing grip strength recovery, aerobic capacity as well as promoting neuroplasticity. The results of these 2 lines of research could be now associated by deepening the HIT effects at cerebral and spinal level that lead to numerous perspectives.