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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Construção de STBCs de Ordem Maximal em Álgebras Centrais Simples

Santos, Josenildo Brandão 28 September 2012 (has links)
Made available in DSpace on 2015-05-15T11:46:12Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 680540 bytes, checksum: fd1c663b0bd1b5f52cc2e595af12efd6 (MD5) Previous issue date: 2012-09-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this dissertation, a way to build dense STBCs with full diversity of maximal order in central simple algebra will be presented. We constructed a retriculated ST code with a nonzero determinant for a quad antenna MISO transmission. Also, we will present a general algorithm to test the limit of a given order, since by the use of a maximum order instead of just the algebraic integer ring, we can increase the capacity of the code without a loss in the minimum determinant. Furthermore, by using the ideal of a maximum order we can further improve the code, as we increase the minimum determinant. / Nesta dissertação, será apresentada uma maneira para construir STBCs denso com diversidade completa, de ordem maximal em álgebras centrais simples. Construiremos um código reticulado ST com determinante não nulo para uma aplicação de quatro an- tenas de transmissão MISO. Apresentaremos também, um algoritmo geral para testar a maximalidade de uma ordem dada, uma vez que com o uso de uma ordem maximal em vez de apenas o anel dos inteiros algébricos, conseguimos um aumento na capacidade do código sem perda no determinante mínimo. Além disso, utilizando o ideal de uma ordem maximal melhoramos ainda mais o código, à medida que aumentamos o determinante mínimo.
82

Utilisation de l'élargissement d'opérateurs maximaux monotones pour la résolution d'inclusions variationnelles / Using the expansion of maximal monotone operators for solving variational inclusions

Nagesseur, Ludovic 30 October 2012 (has links)
Cette thèse est consacrée à la résolution d'un problème fondamental de l'analyse variationnelle qu'est la recherchede zéros d'opérateurs maximaux monotones dans un espace de Hilbert. Nous nous sommes tout d'abord intéressés au cas de l'opérateur somme étendue de deux opérateurs maximaux monotones; la recherche d'un zéro de cet opérateur est un problème dont la bibliographie est peu fournie: nous proposons une version modifiée de l'algorithme d'éclatement forward-backward utilisant à chaque itération, l'epsilon-élargissement d'un opérateur maximal monotone,afin de construire une solution. Nous avons ensuite étudié la convergence d'un nouvel algorithme de faisceaux pour construire ID zéro d'un opérateur maximal monotone quelconque en dimension finie. Cet algorithme fait intervenir une double approximation polyédrale de l'epsilon-élargissement de l'opérateur considéré / This thesis is devoted to solving a basic problem of variational analysis which is the search of zeros of maximal monotone operators in a Hilbert space. First of aIl, we concentrate on the case of the extended som of two maximal monotone operators; the search of a zero of this operator is a problem for which the bibliography is not abondant: we purpose a modified version of the forward-backward splitting algorithm using at each iteration, the epsilon-enlargement of a maximal monotone operator, in order to construet a solution. Secondly, we study the convergence of a new bondie algorithm to construet a zero of an arbitrary maximal monotone operator in a finite dimensional space. In this algorithm, intervenes a double polyhedral approximation of the epsilon-enlargement of the considered operator
83

Samband mellan explosiv och maximal styrka vid Isometric Mid-Thigh-Pull : En tvärsnittsstudie om kraftutveckling / Relationship Between Explosive and Maximal Strength in Isometric Mid-Thigh Pull : A Cross-Sectional Study on Force Development

Nilsson, Jesper, Ågerup, Daniel January 2024 (has links)
Muskelstärkande fysisk aktivitet kan likställas med styrketräning och definieras som fysisk aktivitet med avsikt att förbättra eller bibehålla muskulär styrka, muskelvolym och/eller muskulär uthållighet. Explosiv styrka kan beskrivas som kraftutveckling per tidsenhet och är en produkt av styrka/kraft och hastighet. Tidigare studier har visat att en god explosiv och maximal styrka bland annat kan ge hälsovinster, förbättra idrottslig förmåga, minska risken för idrottsskador och kan förebygga fallrisken hos äldre. Isometric mid-thigh pull-test (IMTP) har under de senaste 10 åren blivit ett vanligt test för att mäta helkroppsstyrka hos idrottare. Testet är lätt att administrera och har en god validitet samt reliabilitet. Studiens syfte var att undersöka sambandet mellan explosiv- och maximal styrka hos styrketränande personer vid ett IMTP-test. Tio deltagare med minst ett års erfarenhet av styrketräning rekryterades. Resultatet visade en måttligt stark korrelation (r = 0,48) mellan explosiv och maximal styrka, men ingen statistisk signifikans (p = 0,158). Deltagarnas Peak Force var i genomsnitt 2644 ± 404 N och Peak force vid 250ms var medel 1808 ± 231 N (i medel hade deltagarna uppnått 69% av Peak Force vid 250ms). Sammanfattningsvis noterades att det möjligen kan finnas en trend i korrelationen mellan explosiv och maximal styrka. Detta indikerar att maximal och explosiv styrka troligen överlappar varandra, det kan däremot inte bekräftas då det inte fanns något statistiskt samband. Vidare rekommenderas att framtida forskning undersöker explosiv styrka och maximal styrka som distinkta styrkeförmågor med fler deltagare och standardiserade testmetoder krävs för att vidare undersöka sambandet mellan maximal och explosiv styrka. / Muscle-strengthening physical activity can be equated with strength training and is defined as physical activity with the intention of improving or maintaining muscular strength, muscle volume, and/or muscular endurance. Explosive strength can be described as force development per unit of time and is a product of strength/power and speed. Previous studies have shown that good explosive and maximal strength can yield health benefits, improve athletic performance, reduce the risk of sports related injuries, and prevent the risk of falls in older adults. The Isometric Mid-Thigh-Pull-test (IMTP) has become a common test for measuring whole body strength in athletes over the past 10 years. The test is easy to administer and has good validity and reliability. The aim of the study was to investigate the relationship between explosive and maximal strength in resistance-trained individuals using an IMTP-test. Ten participants with at least one year’s experience of resistance training were recruited. The results showed a moderately strong correlation (r = 0,48) between explosive and maximal strength, but no statistical significance (p = 0,158). The participants’ Peak Force averaged 2644 ± 404 N, Peak Force at 250ms averaged 1808 ± 231 N (on average, participants had received 69% of Peak Force at 250ms). In summary, it was noted that there might be a trend in the correlation between explosive and maximal strength. This suggests that maximal and explosive strength likely overlap, but this cannot be confirmed as there was no statistical significance. Furthermore, it is recommended that future research investigates explosive strength as distinct strength abilities. More participants and standardized testing methods are required to further explore the relationship between maximal and explosive strength
84

Triple generations of the Lyons sporadic simple group

Motalane, Malebogo John 03 1900 (has links)
The Lyons group denoted by Ly is a Sporadic Simple Group of order 51765179004000000 = 28 37 56 7 11 31 37 67. It(Ly) has a trivial Schur Multiplier and a trivial Outer Automorphism Group. Its maximal subgroups are G2(5) of order 5859000000 and index 8835156, 3 McL:2 of order 5388768000 and index 9606125, 53 L3(5) of order 46500000 and index 1113229656, 2 A11 of order 29916800 and index 1296826875, 51+4 + :4S6 of order 9000000 and index 5751686556, 35:(2 M11) of order 3849120 and index 13448575000, 32+4:2 A5 D8 of order 699840 and index 73967162500, 67:22 of order 1474 and index 35118846000000 and 37:18 of order 666 and index 77725494000000. Its existence was suggested by Richard Lyons. Lyons characterized its order as the unique possible order of any nite simple group where the centralizer of some involution is isomorphic to the nontrivial central extension of the alternating group of degree 11 by the cyclic group of order 2. Sims proved the existence of this group and its uniqueness using permutations and machine calculations. In this dissertation, we compute the (p; q; t)-generations of the Lyons group for dis- tinct primes p, q and t which divide the order of Ly such that p < q < t. For computations, we made use of the Computer Algebra System GAP / Mathematical Sciences / M.Sc. (Mathematics)
85

Reliability of the calculated maximal lactate steady state in amateur cyclists

Adam, Jennifer, Oehmichen, Matthias, Oehmichen, Eva, Rother, Janine, Müller, Ulrike Maria, Hauser, Thomas, Schulz, Henry 13 July 2015 (has links) (PDF)
Abstract provided by Publisher Complex performance diagnostics in sports medicine should contain maximal aerobic and maximal anaerobic performance. The requirements on appropriate stress protocols are high. To validate a test protocol quality criteria like objectivity and reliability are necessary. Therefore, the present study was performed in intention to analyze the reliability of maximal lactate production rate (VLamax) by using a sprint test, maximum oxygen consumption (VO2max) by using a ramp test and, based on these data, resulting power in calculated maximum lactate-steady-state (PMLSS) especially for amateur cyclists. All subjects (n=23, age 26 ± 4 years) were leisure cyclists. At three different days they completed first a sprint test to approximate VLamax. After 60 min of recreation time a ramp test to assess VO2max was performed. The results of VLamax-test and VO2max-test and the body weight were used to calculate PMLSS for all subjects. The intra class correlation (ICC) for VLamax and VO2max was 0.904 and 0.987, respectively, coefficient of variation (CV) was 6.3 % and 2.1 %, respectively. Between the measurements the reliable change index of 0.11 mmol∙l-1∙s-1 for VLamax and 3.3 ml∙kg-1∙min-1 for VO2max achieved significance. The mean of the calculated PMLSS was 237 ± 72 W with an RCI of 9 W and reached with ICC = 0.985 a very high reliability. Both metabolic performance tests and the calculated PMLSS are reliable for leisure cyclists.
86

Influência do treinamento de força sobre a estratégia de prova e o desempenho de corredores de longa distância em um teste contrarrelógio de 10 km / Influence of strength training on pacing strategy and performance in long distance runners in a 10-km running time trial

Mayara Vieira Damasceno 16 October 2015 (has links)
O objetivo do presente estudo foi analisar o impacto de oito semanas de um programa de treinamento de força sobre a estratégia de prova e o desempenho de corredores de longa distância durante uma prova contrarrelógio de 10 km. Antes e após a fase de intervenção com o programa de treinamento de força, dezoito corredores recreacionais divididos nos grupos treinamento (GT) (n = 9) e controle (GC) (n = 9) foram submetidos aos seguintes testes: a) antropometria e teste progressivo até a exaustão voluntária, b) teste com velocidade submáxima constante, c) simulação de uma prova de 10 km para análise da estratégia de prova, d) teste de drop jump, e) teste de wingate, f) teste de uma repetição máxima (1RM) e g) teste de tempo limite. A atividade eletromiográfica dos músculos vasto medial e bíceps femoral foi medida durante o teste de 1RM. No GT, a magnitude de melhora para o 1RM (23,0 ± 4,2%, P = 0,001), drop jump (12,7 ± 4,6%, P = 0,039), e velocidade de pico na esteira (2,9 ± 0,8%, P = 0,013) foi significativamente maior em relação ao GC. Este aumento do 1RM para o GT foi acompanhado por uma tendência a uma maior atividade eletromiográfica (P = 0,080). A magnitude de melhora no desempenho na prova de 10 km foi maior (2,5%) no GT que no GC (-0,7%, P = 0,039). O desempenho foi melhorado principalmente devido a velocidades mais elevadas durante as últimas sete voltas (últimos 2800 m) da prova de 10 km. No entanto, não houve diferenças significativas antes e após o período de treinamento para o padrão de estratégia de prova utilizada, consumo máximo de oxigênio, ponto de compensação respiratória, economia de corrida e desempenho anaeróbio para ambos os grupos (P > 0,05). Em conclusão, estes resultados sugerem que, embora um programa de treinamento de força não altere a estratégia de prova adotada, ele oferece um potente estímulo para combater a fadiga durante as últimas partes de uma corrida de 10 km, resultando em um melhor desempenho total / The aim of the present study was to analyze the impact of an 8-week strength-training program on performance and pacing strategy adopted by runners during a self-paced endurance running. Eighteen endurance runners were allocated into either strength training group (STG, n = 9) or control group (CG, n = 9) and performed the following tests before and after the training period: a) anthropometric measures and maximal incremental treadmill test, b) running speed-constant test, c) 10-km running time trial, d) drop jump test, e) 30-s Wingate anaerobic test, f) maximum dynamic strength test (1RM), g) time to exhaustion test. Electromyographic activity of vastus medialis and biceps femoris was measured during 1RM test. In the STG, the magnitude of improvement for 1RM (23.0 ± 4.2%, P = 0.001), drop jump (12.7 ± 4.6%, P = 0.039), and peak treadmill speed (2.9 ± 0.8%, P = 0.013) was significantly higher compared to CG. This increase in the 1RM for STG was accompanied by a tendency to a higher electromyographic activity (P = 0.080). The magnitude of improvement for 10-km running performance was higher (2.5%) for STG than for CG (-0.7%, P = 0.039). Performance was improved mainly due higher speeds during the last seven laps (last 2800 m) of the 10-km running. Nevertheless, there were no significant differences between before and after training period for pacing strategy, maximal oxygen uptake, respiratory compensation point, running economy, and anaerobic performance for both groups (P > 0.05). In conclusion, these findings suggest that, although a strength-training program does not alter the pacing strategy, it offers a potent stimulus to counteract fatigue during the last parts of a 10-km running, resulting in an improved overall running performance
87

Associação entre o polimorfismo de nucleotídeo único no gene ACTN3, variáveis fisiológicas e parâmetros neuromusculares relacionados à aptidão aeróbia / Association among the single nucleotide polymorphism in the ACTN3 gene, physiological variables and neuromuscular parameters related to aerobic fitness

Pasqua, Leonardo Alves 10 April 2013 (has links)
O objetivo do presente estudo foi investigar a existência de associação entre os diferentes genótipos do polimorfismo R577X do gene ACTN3 e variáveis fisiológicas e neuromusculares associadas à aptidão aeróbia e ao desempenho em provas de longa duração. Cento e cinquenta indivíduos fisicamente ativos foram submetidos aos seguintes testes: a) teste incremental máximo para determinação do consumo máximo de oxigênio, velocidade de pico, limiar ventilatório (LV) e ponto de compensação respiratória (PCR); b) dois testes de cargas constantes nas velocidades de 10 km.h-1 e 12 km.h-1 para determinação da economia de corrida; c) teste de uma repetição máxima no exercício leg press para determinação da força máxima de membros inferiores; d) teste de salto vertical para determinação da potência máxima de membros inferiores e; e) genotipagem para determinação do genótipo do gene ACTN3. Os principais resultados foram a maior representação do genótipo XX entre os indivíduos com maiores velocidades associadas ao LV e ao PCR. Além disso, entre os indivíduos mais econômicos, foi observada uma maior representação de pelo menos uma cópia do alelo X (genótipos RX e XX). Esses resultados sugerem que o genótipo XX do gene ACTN3 parece ser favorável às variáveis fisiológicas associadas à aptidão aeróbia, sobretudo aquelas determinadas em intensidades submáximas / The aim of the present study was to investigate the relationship among the genotypes of the ACTN3 gene and physiological and neuromuscular parameters related to aerobic fitness and endurance performance. One hundred and fifty male physically active subjects performed the following tests: a) a maximal incremental test to determine maximal oxygen consumption, peak velocity, ventilatory threshold and respiratory compensation point; b) two constant speed tests at 10 km.h-1 and 12 km.h-1 to determine running economy; c) one repetition maximum in the leg press to determine the maximal dynamic strength of the lower limbs; d) vertical jump test to determine the maximum power of the lower limbs and; e) genotyping for the ACTN3 gene polymorphism. Our main results were a higher frequency of the XX genotypes among the individuals with the highest speeds associated to ventilatory threshold and to the respiratory compensation point. It was observed a higher frequency of at least one copy of the X allele (RX and XX genotypes) among the more economical individuals. These results suggest that the XX genotype of the ACTN3 gene seems to be associated with physiological variables related with the aerobic fitness, mainly those determined in submaximal intensities
88

Etude des propriétés neuromusculaires chez l'enfant : approche par la stimulation magnétique périphérique / Study of neuromuscular properties in children : approach by peripheral magnetic stimulation

Kluka, Virginie 18 December 2015 (has links)
L’objectif de ce travail était de comparer l’importance de la composante nerveuse dans les différences de production de force entre les enfants et les adultes en tenant compte des conditions mécaniques qui sont susceptibles de l’influencer (longueur musculaire, mode et vitesse de contraction) et des effets de la fatigue. Trente et un garçons pré-pubères de 8-12 ans et 37 hommes de 18-30 ans ont été recrutés et répartis dans les 3 études composant ce projet. La première étude portait sur les effets de la longueur musculaire et de la fatigue sur la production de force et le niveau d’activation maximal volontaire (VA) des extenseurs du genou.La seconde traitait des effets de la longueur musculaire sur la production de force et le VA des fléchisseurs plantaires. Enfin, la troisième portait sur les effets du mode et de la vitesse de contraction sur le VA des extenseurs du genou. Les propriétés neuromusculaires ont été évaluées à l’aide de stimulations magnétiques périphériques et de contractions maximales volontaires. Les résultats montrent un VA des extenseurs du genou supérieur chez l’adulte lors de grande longueur musculaire (90°-100° de flexion) (étude 1), mais aucune différence avec l’enfant à courte longueur musculaire (20° de flexion). En revanche, sur des groupes musculaires tels que les fléchisseurs plantaires, aucun effet de la longueur sur le VA n’a été observé chez les enfants et les adultes (étude 2). En ce qui concerne les effets du mode de contraction, nos résultats montrent que le VA est inférieur en conditions excentrique et concentrique par rapport à la condition isométrique, mais aucune différence n’était observée entre les groupes (étude 3). Toutefois, l’effet de cette baisse de VA sur la production de force variait entre les groupes ; une diminution de force accompagnant la diminution de VA n’était retrouvée que chez l’adulte. Enfin,nous avons montré que la baisse du VA au cours d’un protocole de fatigue est plus conséquente chez les enfants par rapport aux adultes (étude 1), ce qui témoigne de l’existence d’une fatigue centrale majorée chez l’enfant. Une maturation inaboutie et les propriétés musculo-tendineuses particulières de l’enfant (compliance supérieure) pourraient expliquer les résultats obtenus au cours de ce travail. / The purpose of this PhD thesis was to compare the contribution of the maximal voluntary activation level (VA) of the motor units to force production differences between children and adults in various mechanical conditions that affect force production (muscle length, contraction mode and velocity), and in fatigue condition. Thirty one pre-pubertal 8 to 12-year old boys and 37 men (18-30 years) were recruited and allocated into the 3 studies ofthis project. The first study was devoted to compare the effects of muscle length and fatigue on the VA and force generating capacity of the knee extensors between children and adults. In the second study, we compared the effects of muscle length on the VA and force generating capacity of the plantar flexors between children and adults. The third study analysed the effect of contraction mode and velocity on the VA and force generating capacity of the knee extensors between children and adults. Neuromuscular properties were assessed with peripheral magnetic stimulation and maximal voluntary contractions. Results showed a higher VA of the knee extensors in adults at long muscle length (90° and 100° knee flexion) but no difference between children and adults at short length (20° knee flexion; study 1). However, the VA of the plantar flexors was not affected by muscle length changes whatever the age group considered (study 2). Results also showed a higher VA in isometric mode compared to eccentric and concentric conditions whatever the age group (study 3). However, the effect of this VA reduction on force generating capacity differed between groups, a concomitant force reduction being observed in adults, but not in children. Finally, we observed a greater VA reduction and therefore greater central fatigue in children during the fatiguing protocol (study 1). A relative immaturity and the particular musculo-tendinous properties of children (higher compliance) may account for the reported results.
89

Les justes bornes de la richesse : fondements normatifs et mise en oeuvre d'une richesse maximale / Just limits of wealth : normative foundations and implementation of the idea of maximal wealth

Jobin, Christian 02 February 2018 (has links)
Dans cette thèse, je tente d’établir les fondements normatifs d’une richesse maximale qui comprend deux mesures complémentaires : un revenu maximal qui peut être mis en œuvre au moyen d’un impôt sur le revenu et un capital maximal, au moyen d’un impôt sur les successions, dont le taux marginal est de 100 % dans les deux cas. Je soutiens en effet qu’une telle mesure est juste, puisqu’elle respecte les principes développés au sein de trois théories principales : le libertarisme, le suffisantisme et le prioritarisme. Puis, je soutiens aussi qu’une telle mesure est efficace d’un point de vue économique, puisqu’elle permet de mieux diffuser les incitations financières, ce qui peut avoir des effets positifs sur la production et la répartition de la richesse. D’abord, je soutiens qu’une richesse maximale respecte le principe fondamental défendu par les libertariens, c’est-à-dire la propriété de soi. Pour ce faire, je m’appuie surtout sur deux arguments : le proviso et la théorie des marchés où le gagnant rafle la mise. D’abord, je montre que si l’on associe les ressources naturelles au capital, l’application d’un proviso au principe d’acquisition interdit l’appropriation illimitée des ressources naturelles, ce qui permet de justifier un capital maximal. Ensuite, je montre que si l’on associe les fruits du travail au revenu, les marchés où le gagnant rafle la mise permettent à certains individus de recevoir des revenus qui sont supérieurs aux fruits de leur travail, ce qui viole par excès le principe de la propriété de soi et permet de justifier un revenu maximal. Ensuite, je soutiens qu’une richesse maximale respecte les principes développés au sein de deux théories faisant partie de la tradition égalitariste : le suffisantisme et le prioritarisme. Pour ce faire, je montre que ces deux théories ne sont acceptables que si elles intègrent une autre théorie que l’on appelle le limitarianisme. Selon cette théorie, toute richesse supérieure à celle dont un individu a besoin pour s’épanouir pleinement dans la vie peut être qualifiée d’immorale. Par conséquent, une telle théorie permet de justifier une richesse maximale, puisqu’elle ajoute un seuil de richesse au seuil de pauvreté que défendent déjà les suffisantistes et les prioritaristes.Enfin, je réponds à l’une des principales objections qui peuvent être soulevées contre une richesse maximale et qui porte sur l’efficacité économique du plafonnement des incitations financières. Je montre en effet qu’une richesse maximale, contrairement à ce que l’on pourrait croire, pourrait avoir des effets positifs sur la production et la distribution de la richesse. Pour ce faire, je m’appuie surtout sur trois arguments. D’abord, les incitations ont une importance surestimée en sciences économiques. Ensuite, il existe plusieurs formes d’incitations qui ne se réduisent nullement aux seules incitations financières. Enfin, il est préférable de diffuser largement les incitations financières plutôt que de les concentrer exagérément auprès d’une minorité d’individus. / In this thesis, I try to establish the normative foundations for a maximum limit on wealth that includes two complementary measures: a maximum on income that can be implemented by means of an income tax, and a maximum on capital, which can be attained through a tax on inheritance; the marginal rate being 100% in both cases. Indeed, I argue that such a measure is fair, since it respects the principles developed in three main theories : libertarianism, sufficientarianism, and prioritarianism. Next, I argue that such a measure is economically efficient, since it allows to better spread financial incentives, which can have positive effects on the production and distribution of wealth. First, I maintain that a maximum limit on wealth respects the fundamental principle defended by libertarians, that is, self-ownership. To do this, I rely mainly on two arguments: the proviso and the theory of winner-takes-all markets. First, I show that if we associate natural resources with capital, the application of a proviso to the principle of acquisition prohibits the unlimited appropriation of natural resources, which justifies a maximum on capital. Then, I show that if the fruits of labor are associated with income, winner-takes-all markets allow certain individuals to receive incomes that are superior to the fruits of their labor, which violates the principle of self-ownership, and thus justifies a maximum on income. Secondly, I maintain that a maximum wealth respects the principles developed within two theories within the egalitarian tradition: those of sufficientarianism and prioritarianism. To do this, I show that these two theories are acceptable only if they integrate another theory named limitarianism. According to this theory, any wealth superior to that which an individual needs to live a flourishing life can be qualified as immoral. Consequently, such a theory makes it possible to justify a maximum wealth, since it adds a wealth threshold to the poverty threshold already defended by sufficientarians, and prioritarians. Finally, I respond to one of the main objections that can be raised against maximum wealth and which deals with the economic efficiency of the capping of financial incentives. In fact, I show that maximum wealth, contrary to what one might believe, could have positive effects on the production and distribution of wealth. To do this, I rely mainly on three arguments. First, incentives are overestimated in economics. Second, there are several forms of incentives that are not limited to financial incentives alone. Finally, it is preferable to disseminate financial incentives widely rather than to exaggeratedly concentrate them on a minority of individuals.
90

Efeitos de um treinamento concorrente na hidroginástica sobre as variáveis neuromusculares e cardiorrespiratórias de mulheres jovens e pós-menopáusicas / Effects of water-based concurrent training on neuromuscular and cardiorespiratory variables in young and postmenopausal women

Pinto, Stephanie Santana January 2013 (has links)
O objetivo do presente estudo foi comparar os efeitos da manipulação da ordem dos exercícios de força e aeróbico durante o treinamento concorrente na hidroginástica sobre as variáveis neuromusculares e cardiorrespiratórias de mulheres jovens e pósmenopáusicas. No estudo I, 26 mulheres jovens (25,12 ± 2,94 anos) foram aleatoriamente divididas em dois grupos de treinamento: força-aeróbico (FA) (n=13) e aeróbico-força (AF) (n=13). Para o estudo II, 21 mulheres pós-menopáusicas (57,14 ± 2,43 anos) foram divididas, também aleatoriamente, em dois grupos: força-aeróbico (FA) (n=10) e aeróbico-força (AF) (n=11). Em ambos os estudos os sujeitos realizaram o treinamento concorrente no meio aquático, duas vezes na semana durante 12 semanas, executando ambos os tipos de exercícios (aeróbico e força) na mesma sessão de treinamento. O treinamento de força foi realizado com séries em máxima velocidade e o treinamento aeróbico foi executado na frequência cardíaca do segundo limiar ventilatório. Todas as variáveis foram avaliadas antes e após o período de treinamento. Para análise dos dados foi utilizado o teste ANOVA para medidas repetidas com fator grupo (α=0,05). No estudo I, com as mulheres jovens, houve um aumento significativo da força muscular dinâmica máxima, avaliada através do teste de 1 repetição máxima (1RM), de todos os grupos musculares analisados (flexão e extensão de cotovelos e joelhos) após o período de treinamento. O grupo FA apresentou maiores ganhos da força muscular dinâmica máxima dos extensores de joelho em comparação ao grupo AF (43,58 ± 14,00% vs. 27,01 ± 18,05%, respectivamente). Após o treinamento houve um aumento do pico de torque isométrico (PT), avaliado no dinamômetro Biodex, de todos os grupos musculares avaliados (exceção PT extensores de cotovelo), sem diferença entre os grupos FA e AF. Além disso, após o treinamento, houve um aumento significativo da taxa de produção máxima e em diferentes janelamentos (50, 100, 250 ms), durante a contração isométrica voluntária máxima (CIVM) de extensão de joelho, sem diferença entre os grupos FA e AF. Houve um aumento significativo da amplitude máxima isométrica do sinal eletromiográfico (EMG), após o treinamento, dos músculos bíceps braquial e vasto lateral, sem diferença entre os grupos FA e AF. Além disso, observou-se uma diminuição significativa da amplitude submáxima isométrica do sinal EMG dos músculos bíceps braquial em 40% da CIVM, do vasto lateral em 40 e 80% da CIVM e do reto femoral em 80% da CIVM, sem diferença entre os grupos FA e AF após as 12 semanas de treinamento. Após o treinamento, houve um aumento significativo da espessura muscular do bíceps braquial, braquial, vasto medial e reto femoral, sem diferença entre os grupos FA e AF. O percentual de ganho da espessura muscular do vasto lateral e vasto intermédio diferiu significativamente entre os grupos, com maiores ganhos para o grupo que treinou na ordem FA em comparação a ordem AF (vasto lateral: 10,00 ± 7,64% vs. 5,28 ± 3,42%, vasto intermédio: 11,58 ± 5,36% vs. 4,40 ± 3,77%, respectivamente). Para os saltos, após o treinamento, houve um aumento significativo da altura do countermovement jump, sem diferença entre os grupos FA e AF. Por fim, ainda em relação ao estudo I, após o treinamento, houve um aumento significativo do consumo de oxigênio de pico (VO2pico) e referente ao primeiro limiar ventilatório (VO2LV1), sem diferença entre os grupos FA e AF. No estudo II, com as mulheres pós-menopáusicas, após o treinamento, houve um aumento significativo da força muscular dinâmica máxima dos flexores e extensores de cotovelo, sem diferença entre os grupos FA e AF. Para o teste de 1RM de extensão de joelhos, foi observado que o grupo FA apresentou maiores ganhos de força em comparação ao grupo AF (34,62 ± 13,51% vs. 14,16 ± 13,68%). Após o treinamento, houve um aumento significativo do PT dos flexores e extensores de joelho, sem diferença entre os grupos FA e AF. Além disso, houve um aumento significativo da taxa de produção máxima e também nos diferentes janelamentos (50, 100, 250 ms), durante a CIVM de extensão de joelho, sem diferença entre os grupos FA e AF. Houve um aumento significativo da amplitude máxima isométrica do sinal EMG dos músculos vasto lateral e reto femoral, sem diferença entre os grupos FA e AF após 12 semanas de treinamento. Também houve uma diminuição significativa da amplitude submáxima isométrica do sinal EMG do músculo reto femoral em 40% da CIVM, sem diferença entre os grupos FA e AF após o treinamento. Após o treinamento, houve um aumento significativo da espessura muscular de todos os músculos analisados, sem diferença entre os grupos FA e AF (exceto reto femoral). Por fim, no estudo II, após o treinamento, houve um aumento significativo do consumo de oxigênio referente ao segundo limiar ventilatório (VO2LV2), sem diferença entre os grupos FA e AF. Em suma, a ordem exercícios de força seguidos dos exercícios aeróbicos otimizou os ganhos de força muscular dinâmica máxima dos extensores de joelho tanto em mulheres jovens quanto em mulheres pós-menopáusicas, bem como a espessura muscular do quadríceps em mulheres jovens quando comparada com a ordem inversa (aeróbico-força). / The aim of the present study was to compare the effects of the intra-session exercise order (i.e., resistance-aerobic or aerobic-resistance) during water-based concurrent training on the neuromuscular and cardiorespiratory variables in young and postmenopausal women. Twenty-six young women (25.12 ± 2.94 years) were randomly assigned into two groups in study I: resistance-aerobic (RA) (n=13) and aerobicresistance (n=13). For study II, twenty-one postmenopausal women were also randomly assigned into two groups: resistance-aerobic (RA) (n=10) and aerobic-resistance (n=11). In both studies the subjects performed the water-based concurrent training two times a week during 12 weeks, performing both resistance and aerobic training in the same session. The resistance training was performed with sets at maximal effort and the aerobic training with exercises at heart rate corresponding to the second ventilatory threshold. All variables were evaluated before and after training. A repeated measure ANOVA with group factor was used to analyze the data of the present study (α=0.05). After training in study I, with the young women, there was a significant increase in the maximal dynamic strength in all muscle groups (elbow and knee flexors and extensors) evaluated using the one-repetition maximal test (1RM). The RA group presented grater relative gains of the knee extensors maximal dynamic strength compared to the AR group (43.58 ± 14.00% vs. 27.01 ± 18.05%, respectively). After training there was a significant increase of the maximal isometric peak torque (PT) of all muscle groups (except elbow extensor PT) evaluated using the Biodex dynamometer, with no difference between RA and AR groups. In addition, after training there was a significant increase of the maximal rate of force development (RFD) and of the RFD at different windows (50, 100, 250 ms) during the knee extension maximal isometric voluntary contraction (MIVC), with no difference between RA and AR groups. There was a significant increase of the maximal isometric electromyography (EMG) activity of biceps brachii and vastus lateralis after training, with no difference between RA and AR groups. Moreover, the submaximal isometric EMG activity of biceps braachi at 40% of MIVC, the submaximal isometric EMG activity of vastus lateralis at 40% and 80% of MIVC and the submaximal isometric EMG activity of rectus femoris at 80% of MIVC showed lower values after training, with no difference between RA and AR groups. After training, there was a significant increase of the muscle thickness of biceps brachii, brachialis, vastus medialis and rectus femoris, with no difference between RA and AR groups. The relative gains of the muscle thickness of the vastus lateralis and vastus intermedius were greater for the RA group compared to the AR group (vastus lateralis: 10.00 ± 7.64% vs. 5.28 ± 3.42%, vastus intermedius: 11.58 ± 5.36% vs. 4.40 ± 3.77%, respectively). The height of the countermovement jump improved after training, with no difference between RA and AR groups. In addition, the peak oxygen uptake (VO2peak) and corresponding to the first ventilatory threshold (VO2VT1) showed significant increases after training, with no difference between RA and AR groups. In study II, with the postmenopausal women, there was a significant increase in the maximal dynamic strength of the elbow flexors and extensors, with no difference between RA and AR groups. The knee extensors 1RM in the RA group showed greater increases than the AR group (34.62 ± 13.51% vs. 14.16 ± 13.68%). After training, there were significant increases of the knee flexors and extensors PT, with no difference between RA and AR groups. In addition, there was a significant increase in the knee extension maximal RFD and in the knee extension RFD at different windows (50, 100, 250 ms), with no difference between RA and AR groups. Moreover, there were increases of the maximal isometric EMG activity of vastus lateralis and rectus femoris, with no difference between RA and AR groups. Furthermore, the submaximal isometric EMG activity of rectus femoris at 40% of MIVC showed lower values after training, with no difference between RA and AR groups. Also, there were significant increases of the muscle thickness of all muscles evaluated, with no difference between RA and AR groups (except rectus femoris). Significant increase was also observed in the oxygen uptake corresponding to the second ventilatory threshold (VO2VT2) after training, with no difference between RA and AR groups. In summary, the intra-session exercise order with resistance exercises prior to aerobic exercises optimizes the knee extensors maximal dynamic strength gains in young and postmenopausal women, as well as the quadriceps femoris muscle thickness in young women when compared to the inverse order (i.e., aerobic-resistance).

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