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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.
41

Treinamento físico e fatores de risco cardiovascular em homens de meia-idade / Physical training and cardiovascular risk factors in middle-aged

Souza, Giovana Vergínia de, 1973 09 October 2010 (has links)
Orientador: Mara Patrícia Traína Chacon Mikahil / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-17T08:14:35Z (GMT). No. of bitstreams: 1 Souza_GiovanaVerginiade_M.pdf: 994644 bytes, checksum: e9b0cd62bacf4084a01b3c0b64c36702 (MD5) Previous issue date: 2010 / Resumo: A inatividade física aliada ao envelhecimento é um dos principais fatores de risco para as doenças cardiovasculares (DCV). A associação do treinamento com pesos (TP) e aeróbio (TA), ou seja, o treinamento concorrente (TC) tem sido recomendado como prevenção destes fatores de risco cardiovascular. Desta forma o objetivo deste estudo foi comparar as respostas de três tipos de treinamento físico sobre circunferência de cintura (CC), perfil lipídico (HDL, LDL e TG), glicose plasmática, pressão arterial (PA), aptidão aeróbia e força muscular em homens não ativos de meia-idade. Os voluntários (n=50) foram subdivididos em quatro grupos, sendo: três grupos submetidos a 16 semanas de treinamento: aeróbio (TA, n =15), com pesos (TP, n=10) e concorrente (TC, n=13) e grupo controle (GC, n=12), o qual não realizou nenhum tipo de atividade física. Os principais achados deste estudo mostraram após os períodos de treinamento alterações importantes quanto a redução da CC nos grupos TA e TC; reduções no LDL para TP e TC e no triglicerídeos (TG) para todos os grupos treinamento; para o HDL ocorreu aumento apenas para o TA. Para as variáveis funcionais, ocorreram aumentos para o *VO2pico* para os grupos TA e TC, e aumentos na força máxima de membros superiores para TP e TC e dos membros inferiores para todos os grupos treinamento. Nossa hipótese de que o TC realizado com duração da sessão e frequencia semanal similar ao TA e ao TP resulte em respostas mais efetivas no controle dos fatores de risco de doenças cardiovasculares foi confirmada pelos presentes achados. Novas propostas de periodizações de treinamento concorrente ainda são necessárias, em especial, para períodos de treinamento mais prolongados no grupo etário estudado. / Abstract: Physical inactivity along ageing is one of the main risk factors of coronary heart disease (CHD). The association of resistance- (RT) and endurance training (ET), in other words, concurrent training (CT) has been recommended as prevention of these cardiovascular risk factors. In this way, the aim of the study was to compare responses of three different physical training regimes on waist circumference, lipid profile, plasma glucose, blood pressure, cardiorespiratory fitness and muscle strength in non-active middle-aged men. The subjects (n=50) were subdivided into four groups, where: three groups performed 16 weeks of training: endurance (ET, n =15), resistance (RT, n=10) and concurrent (CT, n=13), and control group (CG, n=12), which did not perform any kind of physical activity. The main findings of this study showed after the training periods important alterations related to reduction on waist circumference WC in ET and CT groups; reductions in low-density lipoprotein cholesterol (LDL-C) levels in RT and CT groups and in triglycerides (TG) for all training groups; related to high-density lipoprotein (HDL) levels there was an increase only in ET group. For functional variables there was an increase in VO2peak only in ET and CT groups, and an increase in maximal muscle strength for upper body in RT and CT groups. Our hypothesis that CT performed with session durations and weekly frequency similar to ET and RT results in more effective responses in controlling cardiovascular risk factors was confirmed by the present data. New periodizations proposals for concurrent training are still necessary, in special, for longer training periods. / Mestrado / Ciencia do Desporto / Mestre em Educação Física
42

Treinamento concorrente = efeito sobre marcadores inflamatórios sistêmicos e indicadores funcionais em homens de meia idade / Concurrent training : effect on systemic inflammatory markers and functional indicators on middle aged men

Libardi, Cleiton Augusto 18 August 2018 (has links)
Orientador: Mara Patrícia Traína Chacon Mikahil / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-18T07:02:50Z (GMT). No. of bitstreams: 1 Libardi_CleitonAugusto_D.pdf: 1347959 bytes, checksum: 1efe267aea8c3fbad88b5f05525d24d6 (MD5) Previous issue date: 2011 / Resumo: Esta tese é composta de dois artigos científicos originais. O primeiro intitulado "Efeito do treinamento concorrente na força máxima, limiar anaeróbio e VO2pico. em homens meia-idade" teve como objetivo verificar o efeito de 16 semanas de treinamento de força (TF), treinamento aeróbio (TA) e treinamento concorrente (TC) na força máxima, limiar ventilatório (LV), ponto de compensação respiratória (RCP) e consumo de oxigênio pico (VO2pico ) em homens de meiaidade. O segundo manuscrito "Efeito do TF, TA e TC sobre o fator de necrose tumoral-a (TNF- a), a interleucina-6 (IL-6) e protéica C-reativa (PCR) de homens de meia-idade saudáveis" teve como objetivo verificar o efeito de 16 semanas nesses três regimes de treinamento sobre marcadores inflamatórios de homens de meia-idade saudáveis. Os treinamentos foram compostos de duas etapas (E1 e E2) com duração de 8 semanas cada, e freqüência de 3 sessões/semana (TF: 10 exercícios com 3 x 8-10 RM; TA: 60 min de caminhada ou corrida a 55-85% VO2pico; TC: 6 exercícios com 3 x 8-10 RM, seguido de 30 min de caminhada ou corrida a 55-85% VO2pico ). A força máxima aumentou significativamente para o TF e TC nos exercícios supino reto (20,32%; 18,79%), leg press (37,62%; 30,86%) e flexão dos cotovelos (11,89%; 15,58%), sem diferenças significantes entre as modificações. O TA apresentou aumento significante somente no leg press (19%). O LV e o RCP aumentaram para o TA (48,93%; 46,33% respectivamente). Já para o TC, houve aumento significante somente para o LV (28,22%). A potência aeróbia (VO2pico) aumentou significantemente para TA (20,42%) e TC (14,24%). Não houve alterações significantes no TNF- a, IL-6 e PCR após o período de treinamento. Dessa forma, podemos concluir que 16 semanas de treinamento de TF, TA e TC, não afetam baixos e moderados níveis de IL-6, TNF-a e PCR em homens de meia-idade saudáveis. Com tudo, o TC promoveu aumento na força máxima similar ao TF, bem como aumento no limiar ventilatório e VO2pico semelhante ao TA / Abstract: This thesis is composed of two original articles. The first titled "Effect of concurrent training on maximal strength, anaerobic threshold and VO2peak. middle-aged men" aimed to determine the effect of 16 weeks of resistante training (RT), endurance training (ET) e concurrent training (CT) in maximal strength, ventilatory threshold (VT), respiratory compensation point (RCP) e peak oxygen uptake (VO2peak) in middle-aged men. The second manuscript entitled "Effect of resistance, endurance and concurrent training on the TNF-a, IL-6 and PCR in middleaged men healthy" aimed to evaluate the effects of 16 weeks of resistance, endurance and concurrent training on the TNF-a, IL-6, C-reactive protein (CRP) and functional capacity in sedentary middle-aged men. They performed three weekly sessions for 16 weeks (RT: 10 exercises with 3 x 8-10 RM; ET: 60 min of walking or running at 55-85% VO2peak ; CT: 6 exercises with 3 x 8-10 RM, followed by 30 min of walking or running at 55-85% VO2peak ). Maximal strength was tested in the bench press, leg press and arm curl exercises. The peak oxygen uptake (VO2peak) was measured by an incremental exercise test. Tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6) and C-reactive protein (CRP) were determined by ELISA. Maximal strength increases for RT and CT in bench press (20,32% and 18,79%, respectively), leg press (37,62% and 30,86%, respectively) and arm curl (11,89% and 15,58%, respectively). The ET showed significantly increase in leg press (19%). The VT and RCP increased for ET (48,93% and 46,33%, respectively). The CT, showed significant enhance only in VT (28,22%). VO2peak presented significant increase for ET (20,42%) and CT (14,24%). There were no significant differences in TNF-a, IL-6 and CRP plasma levels during the study. These findings demonstrated that 16 weeks of resistance, endurance or concurrent training in middle-aged healthy men have not affected low and moderate IL-6, TNF-a and CRP levels. Concurrent training performed in the same weekly frequency and session duration of endurance and resistance training was effective in increasing both maximal strength and peak oxygen uptake / Doutorado / Ciencia do Desporto / Doutor em Educação Física
43

Fysioterapeuters beskrivning av att stötta patienter med depression till fysisk aktivitet : En kvalitativ intervjustudie

Starkensjö, Veronica, Isaksson, Aron January 2022 (has links)
Bakgrund: Den psykiska ohälsan i samhället ökar samtidigt som depression är en av de vanligaste psykiatriska diagnoserna. Nuvarande evidens visar på att fysisk aktivitet har en lika stor positiv påverkan på mild till måttlig grad depression som antidepressiva läkemedel. Syfte: Syftet med studien är att utforska fysioterapeuters beskrivning av hur de stöttar patienter med depression till fysisk aktivitet. Metod: En kvalitativ deskriptiv intervjustudie med sju fysioterapeuter som har rekryterats genom bekvämlighets- och ändamålsenligt urval. Datainsamlingen har skett genom semistrukturerade intervjuer och dataanalysen genom manifest kvalitativ innehållsanalys med induktiv ansats.  Resultat: Resultatet visar på att fysioterapeuter använder sig av både fysisk aktivitet och träning, såväl som mental träning vid behandling. Informanterna beskriver att patientgruppen behöver en längre behandlingsperiod med mer närvaro, stöttning och uppföljning jämfört med andra patientgrupper.  Slutsats: Stöttning av en fysioterapeut vid depression kan leda till att patienten blir fysiskt aktiv och vidmakthåller den. För att lyckas med stöttningen beskrivs beteendemedicinska strategier som en viktig del. Även bemötande av patienten beskrivs som en nyckelfaktor. Med sin kunskap om fysisk aktivitet och hur det påverkar personer har fysioterapeuter en viktig roll vid behandling av depression.
44

Implication du retrait de l'action estrogénique dans le développement de la stéatose hépatique non-alcoolique

Paquette, Amélie January 2008 (has links)
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.
45

Påverkas människan på olika sätt av uthållighetsträning på fastande respektive icke-fastande mage vad gäller fysiologiska markörer i kroppen?

Olsson, Pontus January 2017 (has links)
Inledning: Uthållighetsträning definieras som den typ av träning där flertalet stora muskelgrupper används och är i behov av hjärt-kärlsystemets kapacitet för att transportera syre till musklerna. Att fasta innebär i de flesta studier att ingen typ av föda intas före träningspassen medan att inte fasta vanligtvis innebär att 90 minuter före ett träningspass intas en kolhydratrik måltid. Insulin är viktig i fett-, protein- och kolhydratmetabolismen samt i uppsamlingen av socker i blodet. Glykogen fungerar som en energireserv i skelettmusklerna. Fria fettsyror är viktiga för att ge energi till den cellulära metabolismen som ska kunna fortgå. Syfte: Syftet med denna studie var att ta reda på om kroppen påverkas på olika sätt av uthållighetsträning på fastande respektive icke-fastande mage vad gäller insulin, muskelglykogen samt fria fettsyror hos människor. Metod: Litteratursökning i OneSearch med sökorden training* AND fasted state där sex artiklar valdes ut. Cohen’s D användes för att ge studiernas resultat en effektstorlek. Konfidensintervall användes för att bestämma om studierna var statistiskt signifikanta. Resultat: Tre studier undersökte insulin där resultaten visade att samtliga grupper som inte fastade före träningspassen hade lägst koncentration av insulin i viloperioden efter eftertestet. Samtliga sex studier undersökte muskelglykogen där resultaten visade att koncentrationen av muskelglykogen var högst efter eftertestet i gruppen som fastade före träningspassen i fem av sex studier. Tre studier undersökte fria fettsyror där resultaten visade att koncentrationen av fria fettsyror var lägst i eftertestet i gruppen som fastade före träningspassen i två av tre studier. Diskussion: Träning i icke-fastat tillstånd leder till att glykogennivåerna sparas vilket i sin tur leder till att oxidationen av insulin ökar vilket resulterar i lägre koncentrationer av insulin efter eftertestet. Träning i fastat tillstånd resulterar i ökad koncentration av muskelglykogen till energiunderhåll samt högre nivåer av β-hydroxyacyl coenzym A dehydrogenas (β-HAD), citratsyntasaktiviteten (CS-aktiviteten) samt succinatdehydrogenasaktiviteten vilket leder till ökad muskulär oxidativ kapacitet. Intag av kolhydrater före ett träningspass leder till ökat glykogenbesparande vilket resulterar i lägre koncentrationer av muskelglykogen jämfört med icke-fastat tillstånd. Högre koncentration av muskelglykogen före förtestet leder till högre koncentrationer av muskelglykogen i eftertestet. Träning i fastat tillstånd resulterar i lägre koncentrationer av fria fettsyror på grund av ökad FATmax (den maximala hastigheten av fettförbränning), ökad maximal oxidativ enzymaktivitet, uppreglering av hormonkänsligt lipas (HSL), ökat proteinuttryck av fettsyra-translokas / CD36 (FAT / CD36) samt ökat membranbundet proteinbindande protein som leder till ökad fettförbränning. Koncentrationen av fria fettsyror höjdes även i en studie på grund av att insulinutsöndringen inte skulle sjunka för lågt i gruppen som fastade före träningspassen. Konklusion: Resultaten visade att i tre av tre studier var insulinkoncentrationen lägst efter eftertestet i gruppen som intog en kolhydratrik måltid före träningspassen. I fem av sex studier var koncentrationen av muskelglykogen högst efter eftertestet i gruppen som fastade före träningspassen. I två av tre studier var koncentrationen av fria fettsyror lägst efter eftertestet i gruppen som fastade före träningspassen. Dessa resultat ökar förståelsen av hur träning på fastande respektive icke-fastande mage påverkar kroppen med avseende på insulin, muskelglykogen samt fria fettsyror. Vidare forskning skulle kunna undersöka dessa tre fysiologiska markörer under sex månader för att se om resultaten blir desamma i dessa två grupper. / Introduction: Endurance training is defined as the type of exercise where most major muscle groups are used in need of the cardiovascular system’s ability to transport oxygen to the muscles. Fasting means in most studies that no type of food is taken before the workout while not fasting usually means that a carbohydrate meal is taken 90 minutes before a workout. Insulin is important in fat, protein and carbohydrate metabolism as well as in the collection of sugar in the blood. Glycogen acts as an energy reserve in the skeletal muscles. Free fatty acids are important to provide energy for the cellular metabolism that can continue. Aim of the study: The aim of the study was to find out if the body is affected in different ways by endurance training exerted in fasted respectively non-fasting state regarding insulin, muscle glycogen and free fatty acids in humans. Methods: Literature search in OneSearch with the words training* AND fasted state where six articles were selected. Cohen’s D was used to give the results of the studies an effect size. Confidence interval was used to determine if the studies were statistically significant. Results: Three studies investigated insulin, where the results showed that all groups that did not fast before the workouts had the lowest concentration of insulin during the rest period after the test. All six studies investigated muscle glycogen, where the results showed that the concentration of muscle glycogen was highest after post-test in the group that fasted before the workouts in five out of six studies. Three studies investigated free fatty acids where the results showed that the concentration of free fatty acids were lowest in the post-test in the group that fasted before the workouts in two of three studies. Discussion: Training in the non-fasting state causes the glycogen levels to be saved, which in turn leads to increased oxidation of insulin resulting in lower concentrations of insulin after the post-test. Training in the fasted state results in increased concentration of muscle glycogen for energy maintenance and higher levels of β-hydroxyacyl coenzyme A dehydrogenase (β-HAD), citrate synthase activity (CS activity) and succinate dehydrogenase activity, leading to increased muscular oxidative capacity. Intake of carbohydrates prior to a workout leads to increased glycogen saving, resulting in lower concentrations of muscle glycogen compared to non-fasted state. Higher concentration of muscle glycogen before the pretest leads to higher concentrations of muscle glycogen in the post-test. Training in fasted state results in lower concentrations of free fatty acids due to increased FATmax (maximum rate of fat burning), increased maximal oxidative enzyme activity, hormone sensitive lipase (HSL) upset, increased fatty acid translocase / CD36 protein expression (FAT / CD36) as well as increased membrane bound protein binding protein which leads to increased fat burning. The concentration of free fatty acids was also increased in a study due to the fact that insulin secretion should not fall too low in the group that fasted before the workouts. Conclusion: The results showed that in three out of three studies, the insulin concentration was lowest after the post-test in the group who took a carbohydrate meal before the workouts. In five out of six studies, the concentration of muscle glycogen was highest after the post-test in the group that fasted before the workouts. In two out of three studies, the concentration of free fatty acids was lowest after the post-test in the group that fasted before the workouts. These results increase the understanding of how exercise in the fasted state and non-fasted state affects the body with regard to insulin, muscle glycogen and free fatty acids. Further research could investigate these three physiological markers for six months to see if the results are the same in these two groups.
46

Heart rate variability in relation to the menstrual cycle in trained and untrained women

Spielmann, Nadine 05 January 2005 (has links)
Einleitung: Es wird angenommen, dass die zyklusbedingten, hormonellen Änderungen die vegetative Ansteuerung des Herzens bei normotensiven Frauen beeinflussen. Die Herzfrequenzvariabilität (HRV) stellt einen der am häufigsten untersuchten, nicht-invasiven Parameter des Herz-Kreislauf-Systems dar. Deshalb war es das Ziel dieser Studie, den Verlauf der HRV Parameter bei ausdauertrainierten als auch untrainierten normotensiven Frauen in Abhängigkeit vom Menstruationszyklus zu untersuchen. Methode: Normotensive, untrainierte als auch trainierte Frauen nahmen an der Studie teil. Die Athletinnen absolvierten individuell abgestimmte Trainingspläne (>5h/Woche) während der Studie. Die HRV Messungen wurden in den folgenden fünf Zyklusphasen aufgezeichnet: In der Menstruation (M), der Mitte der Follikel- (MidF), der Ovulations- (O), der Mitte der Luteal- (MidL) und der Pre-Menstruationsphase (PreM). Die Basaltemperatur als auch die Hormonanalysen des Luteinisierenden (LH) und des Follikelstimulierenden Hormons (FSH), des β-17 Östrogens (E2) und des Progesterons (P) dienten der Verifizierung der Zyklusphasen. Die HRV Messungen wurden bei Spontanatmung im Liegen (20 min) wie auch während eines Orthosthase Tests aufgezeichnet. Parameter der Zeit als auch der Frequenzdomäne für Kurzzeitmessungen wurden ausgewertet. Resultate: Alle Frauen hatten einen normotensiven Menstruationszyklus mit typischen hormonellen Schwankungen und einem signifikanten Verlauf (p / Introduction: The autonomic control of the heart is assumed to be affected by endogenous hormonal fluctuations in normal ovulatory females. Analyzing heart rate variability (HRV) had become a tool for the noninvasive measurement of cardiac autonomic control. The purpose of the present study was to investigate the course of the HRV parameters in moderately active as well as in long time endurance trained women during the menstrual cycle. Methods: Normal ovulatory females, untrained and trained were enrolled. Female athletes were involved in individually different training patterns (>5h/week) during the study. HRV recordings were obtained during five different menstrual cycle phases: menstruation (M), middle of follicular (MidF), ovulation (O), middle of luteal (MidL) and pre menstruation phase (PreM). Phases were verified by basal body temperature and analysis of luteinizing hormone (LH), follicular stimulation hormone (FSH), β-17 estrogen (E2) and progesterone (P). HRV measurements took place at subjects’ spontaneous breathing frequency in supine position (20 min) as well as during an orthostatic test. Parameters of short-term recording were calculated in time and frequency domain. Results: All women had normal ovulatory menstrual cycles including typical endogenous hormonal fluctuations; levels of LH, FSH, E2 and P were significantly different (p
47

Déterminants mitochondriaux de l'oxydation des acides gras : modulation par l'entraînement, l'hypoxie et un agoniste PPAR-δ / Mitochondrial factors involved in fatty acid oxydation : alteration induced by endurance training, hypoxia and a PPAR-δ

Malgoyre, Alexandra 27 April 2011 (has links)
La plasticité mitochondriale à l'égard de l'oxydation de substrats, et sa participation à la transition métabolique ont été étudiées dans deux conditions: l'exposition chronique à l'hypoxie et l'entraînement en endurance, connues comme modulatrices de la préférence de substrats. Ainsi l'affinité pour le palmitoyl carnitine est augmentée par l'hypoxie et la restriction calorique alors qu'au contraire le flux maximal de palmitoyl CoA (PCoA) semble freiné par l'hypoxie. Quant aux effets de l'entraînement, malgré une amélioration du temps limite de course à intensité sous-maximale et une augmentation des capacités oxydatives globales, nous ne retrouvons pas de facilitation de l'oxydation du PCoA. Par ailleurs, on observe une augmentation des messagers PPAR-delta et d'UCP-3 en réponse à une exposition aigue à l'hypoxie. Le rôle de PPAR-delta sur la modulation de l'utilisation de substrats par la mitochondrie a aussi été envisagé en utilisant un agoniste pharmacologique de PPAR-delta, le GW 742. Celui-ci, permet d'améliorer l'efficacité catalytique du complexe enzymatique CPT-1 tout en limitant l'oxydation du pyruvate, également diminuée dans les muscles oxydatifs au cours de la restriction calorique. Le traitement par GW 742, s'il limite l'altération de l'efficacité catalytique de CPT-1 observée en hypoxie, ne permet pas de rétablir, un niveau d'oxydation en PCoA similaire à celui observé en situation contrôle. Le GW 742 s'est aussi montré capable de restaurer le flux en PCoA altéré par l'entraînement, même si la fonction du transport CPT-1 reste limitante devant l'augmentation du potentiel oxydatif induit par l'entraînement. Par ailleurs, nous n'avons pas retrouvé de relation étroite entre les variations d'affinité en PCoA et la performance aérobie sous-maximale, pourtant influencée par la capacité à oxyder préférentiellement les lipides. Enfin, la diminution du flux en pyruvate associée à l'augmentation de l'utilisation des acides gras à longue chaîne observée lors du traitement par GW 742 ou au cours de la restriction calorique pose la question du rôle joué par une cible particulière de PPAR-delta sur la mitochondrie, la protéine découplante UCP-3. / Substrate oxidation and its contribution to metabolic shift, as markers of muscle plasticity have been studied under two specific condition, the prolonged exposure to ambient hypoxia, and endurance training, two conditions known as leading to changes in substrate use. Our result show that the affinity for palmitoyl carnitine is increased by both hypoxia and food restriction, whereas in contrast exposure to hypoxia slow down the palmitoyl CoA (PCoA) maximal use. On the other hand, endurance training led to enhanced physical performance and increased muscular oxidative capacities, but failed to enhance PCoA oxidation. The transcripts for PPAR-delta and UCP-3 increased in response to aucte exposure to hypoxia. Moreover, we studied the role played by PPAR-delta on the substrate use modulation, using new PPAR-delta agonist known as GW 742. In the present study, this new pharmacological substance has been shown to enhance the catalytic efficiency of CPT-1 and decrease the pyruvate oxidation. Moreover, GW 742 administration limits the hypoxia-induced decrease of CPT-1 activity, but failed to recover levels of PCoA oxidation similar to those observed in control conditions. GW 742 administration was able to suppress the effects of training on maximal PCoA oxidation, even if the functional CPT-1 activity remains limiting regarding the training-induced increase in oxidative capacity. On the other hand, we failed to show strong relationship between PCoA affinity and physical performance. Finally, the concomitant increase in long chain fatty acid oxidation and decrease in pyruvate oxidation resulting from either GW 742 use or food restriction, addresses the issue of the role played by the uncoupling protein UCP-3 on mitochondrial function
48

Fonction mitochondriale et espèces réactives dérivées de l'oxygène : effets du genre et de l'entraînement en endurance chez le rat Wistar et l'anguille européenne / Mitochondrial function and reactive oxygen species : effects of gender and endurance training in Wistar rat and European eel

Farhat, Firas 20 March 2015 (has links)
La mitochondrie est le siège principal de la production d’énergie sous forme d’ATP en conditions aérobies, mais aussi d’espèces réactives dérivées de l’oxygène (ROS). La fonction mitochondriale est étroitement liée à la production de ROS puisque ces derniers, selon leur taux, peuvent altérer ou optimiser le rendement énergétique. La plasticité structurale et fonctionnelle de la mitochondrie est essentielle au maintien de l’homéostasie dans toute situation qui nécessite des ajustements métaboliques comme l’exercice physique. Les mécanismes adaptatifs de la fonction mitochondriale et des ROS lors de l’entrainement sont encore loin d’être élucidés ainsi que l’impact du genre sur ces réponses. Dans cette perspective, deux modèles animaux (rat Wistar et anguille européenne) ont été choisis. Les effets d’un entrainement en endurance de même intensité (70% de la vitesse maximale aérobie de course ou de nage) ont été étudiés chez le rat Wistar et l’anguille européenne argentée. Cette dernière est une espèce endurante capable d’effectuer une migration de reproduction de 6000 km et caractérisée par un dimorphisme sexuel de taille. Des mesures in vitro de la consommation d’oxygène, la production radicalaire et d’ATP ont été effectuées simultanément à partir de fibres perméabilisées de cœur et de muscle squelettique. La vulnérabilité ou résistance de la fonction mitochondriale à l’exposition à un système générateur de ROS (mimant un stress oxydant) a également été étudiée. Avant entrainement, chez le rat Wistar, la femelle présente une fonction mitochondriale plus efficiente énergétiquement et plus résistante aux ROS, alors que chez l’anguille, ce profil métabolique et radicalaire est plutôt observé chez le mâle. Après entrainement, quelle que soit l’espèce, la meilleure performance physique observée s’accompagne de modifications métaboliques et radicalaires différentes selon le genre et l’espèce. Chez le rat, l’amélioration de la fonction mitochondriale se traduit différemment selon le sexe. Chez le mâle, l’entrainement induit une amélioration du rendement énergétique via un meilleur couplage entre oxydation et phosphorylation et/ou une meilleure utilisation des électrons au niveau de la chaine respiratoire. Chez la femelle, l’augmentation de la production d’ATP serait liée à l’augmentation de la consommation d’oxygène mitochondriale. Comme chez le rat, l’entraînement induit globalement chez l’anguille une amélioration du rendement énergétique et de la résistance de la fonction mitochondriale aux ROS, mais uniquement chez le mâle. L’ensemble de ces résultats montre des réponses métaboliques et radicalaires dépendantes du genre. Quelle que soit l’espèce, l’entrainement semble être chez le mâle plus bénéfique que chez la femelle en termes d’efficacité énergétique mitochondriale et de résistance de la fonction mitochondriale à un stress oxydant. Dans le contexte de la migration de l’anguille, ces adaptations permettraient au mâle, largement plus petit que la femelle, une efficacité de nage supérieure, permettant leur synchronisation d’arrivée sur le lieu de reproduction. Les similitudes interspécifiques de réponse à l’entraînement selon le genre confortent l’intérêt d’utilisation du modèle poisson dans le champ de la physiologie de l’exercice. / Mitochondrion is the main site of aerobic energy (ATP) and reactive oxygen species (ROS) productions. Mitochondrial function is closely linked to ROS, which, according their rate, can alter or optimize energy efficiency. Structural and functional plasticity of mitochondria is essential to maintain homeostasis in any situation that requires metabolic adjustments as physical exercise. The adaptive mechanisms of mitochondrial function and ROS during training and the impact of gender on these responses are still far from being solved. In this perspective, two animal models (Wistar rat and European eel) were chosen.The effects of endurance training of the same intensity (70% of maximal aerobic speed running or swimming) were studied in Wistar rat and silver European eel. The latter is an enduring species capable of performing a spawning migration of 6000 km and characterized by sexual dimorphism in size. In vitro measurements of oxygen consumption, free radical and ATP productions were carried out simultaneously from heart and skeletal muscle permeabilized fibers. The vulnerability or resistance of the mitochondrial function to a ROS generating system exposure (mimicking oxidative stress) was also studied.Before training, in rat, female has a mitochondrial function energetically more efficient and more resistant to ROS, whereas in eel, this metabolic and radical profile is observed rather in male. After training, whatever the species, the improved physical performance observed is associated with various metabolic and radical changes which depending on gender and species. In rats, the improving of mitochondrial function translates differently according to gender. In male, training induces improvement in energy efficiency through a better coupling between oxidation and phosphorylation and/or better use of electrons at the respiratory chain level. In female, increasing in ATP production may be related to the increase in mitochondrial oxygen consumption. As in rats, training induces globally in eel an improvement in energy efficiency and resistance of mitochondrial function to ROS, but only in male. All these results show metabolic and radical responses depending on gender. Whatever the species, training seems to be most beneficial in males than in females in terms of mitochondrial energy efficiency and resistance of mitochondrial function to oxidative stress. In the context of eel migration, these adaptations allow to male, largely smaller than female, a higher swim efficiency, allowing their synchronization on breeding site. Interspecific similarities in training response by gender confirm the interest of fish model’s using in the field of exercise physiology.
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Physical Training and Testing in Patients with Chronic Obstructive Pulmonary Disease (COPD)

Arnardóttir, Ragnheiður Harpa January 2007 (has links)
<p>The overall aims of the studies were to investigate the effects of different training modalities on exercise capacity and health-related quality of life (HRQoL) in patients with moderate or severe COPD and, further, to explore two of the physical tests used in pulmonary rehabilitation.</p><p>In <b>study I</b>, the 12-minute walking distance (12MWD) did not increase on retesting in patients with exercise-induced hypoxemia (EIH) whereas 12MWD increased significantly on retesting in the non-EIH patients. In <b>study II</b>, we found that the incremental shuttle walking test was as good a predictor of peak exercise capacity (W peak) as peak oxygen uptake (VO<sub>2</sub> peak) is. In <b>study III</b>, we investigated the effects of two different combination training programmes when training twice a week for eight weeks. One programme was mainly based on endurance training (group A) and the other on resistance training and callisthenics (group B). W peak and 12MWD increased in group A but not in group B. HRQoL, anxiety and depression were unchanged in both groups. Ratings of perceived exertion at rest were significantly lower in group A than in group B after training and during 12 months of follow-up. Twelve months post-training, 12MWD was back to baseline in group A, but significantly shorter than at baseline in group B. Thus, a short endurance training intervention delayed decline in 12MWD for at least one year. Patients with moderate and severe COPD responded to training in the same way. In <b>study IV</b>, both interval and continuous endurance training increased W peak, VO<sub>2</sub> peak, peak exhaled carbon dioxide (VCO<sub>2</sub> peak) and 12MWD. Likewise, HRQoL, dyspnoea during activities of daily life, anxiety and depression improved similarly in both groups. At a fixed, submaximal workload (isotime), the interval training reduced oxygen cost and ventilatory demand significantly more than the continuous training did.</p>
50

Physical Training and Testing in Patients with Chronic Obstructive Pulmonary Disease (COPD)

Arnardóttir, Ragnheiður Harpa January 2007 (has links)
The overall aims of the studies were to investigate the effects of different training modalities on exercise capacity and health-related quality of life (HRQoL) in patients with moderate or severe COPD and, further, to explore two of the physical tests used in pulmonary rehabilitation. In study I, the 12-minute walking distance (12MWD) did not increase on retesting in patients with exercise-induced hypoxemia (EIH) whereas 12MWD increased significantly on retesting in the non-EIH patients. In study II, we found that the incremental shuttle walking test was as good a predictor of peak exercise capacity (W peak) as peak oxygen uptake (VO2 peak) is. In study III, we investigated the effects of two different combination training programmes when training twice a week for eight weeks. One programme was mainly based on endurance training (group A) and the other on resistance training and callisthenics (group B). W peak and 12MWD increased in group A but not in group B. HRQoL, anxiety and depression were unchanged in both groups. Ratings of perceived exertion at rest were significantly lower in group A than in group B after training and during 12 months of follow-up. Twelve months post-training, 12MWD was back to baseline in group A, but significantly shorter than at baseline in group B. Thus, a short endurance training intervention delayed decline in 12MWD for at least one year. Patients with moderate and severe COPD responded to training in the same way. In study IV, both interval and continuous endurance training increased W peak, VO2 peak, peak exhaled carbon dioxide (VCO2 peak) and 12MWD. Likewise, HRQoL, dyspnoea during activities of daily life, anxiety and depression improved similarly in both groups. At a fixed, submaximal workload (isotime), the interval training reduced oxygen cost and ventilatory demand significantly more than the continuous training did.

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