• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 25
  • 5
  • 2
  • 1
  • Tagged with
  • 34
  • 34
  • 22
  • 22
  • 10
  • 9
  • 8
  • 8
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 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.
21

Recuperação autonômica cardíaca de jogadores de futsal

Ferreira Júnior, Antônio José 29 April 2013 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-05T11:43:16Z No. of bitstreams: 1 antoniojoseferreirajunior.pdf: 530442 bytes, checksum: 383c11e46d5d70e83ab4f172aa5d0e81 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-09-06T14:19:43Z (GMT) No. of bitstreams: 1 antoniojoseferreirajunior.pdf: 530442 bytes, checksum: 383c11e46d5d70e83ab4f172aa5d0e81 (MD5) / Made available in DSpace on 2016-09-06T14:19:43Z (GMT). No. of bitstreams: 1 antoniojoseferreirajunior.pdf: 530442 bytes, checksum: 383c11e46d5d70e83ab4f172aa5d0e81 (MD5) Previous issue date: 2013-04-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O futsal é um esporte intermitente com muitas substituições e pausas durante a partida, o que possibilita a recuperação de variáveis fisiológicas durante esses momentos, proporcionando ao jogador, assim, disputar a partida em alta intensidade. O processo de recuperação pós-exercício é mediado por uma complexidade de fenômenos fisiológicos. Devido à diversidade de fenômenos fisiológicos envolvidos na recuperação autonômica cardíaca, tais como, catecolaminas, concentração de lactato, pH, amônia, temperatura, volume plasmático, etc., esse parâmetro tem sido utilizado como um indicador de recuperação no âmbito desportivo. Sabe-se que fatores como aptidão aeróbia e treinamento influenciam na recuperação autonômica cardíaca. Na presente dissertação, focou-se no estudo da recuperação autonômica cardíaca de jogadores de futsal. No primeiro estudo, investigou-se a influência do lastro do treinamento de futsal na recuperação da modulação autonômica cardíaca. Participaram deste estudo jogadores de futsal e indivíduos ativos com praticamente o mesmo nível de aptidão física dos atletas, com VO2máx de 49,4 ± 3,4 e de 50,1 ± 5,8 ml.kg.min-1, respetivamente. Avaliou-se a recuperação da modulação autonômica cardíaca nos cinco primeiros minutos de recuperação com a utilização do índice RMSSD30s normalizado, índice relacionado à atividade vagal. Observou-se que os jogadores de futsal apresentaram recuperação da modulação autonômica maior do que os indivíduos ativos a partir dos 90 s de recuperação (LnRMSSD30s 0,84 ± 0,43 e 0,64 ± 0,17 ms respectivamente). Neste estudo se observou, também, que os jogadores de futsal apresentaram reativação vagal, enquanto os indivíduos ativos apresentaram supressão vagal durante todos os cinco minutos da recuperação. Conclui-se que o treinamento do futsal, devido à dinâmica do jogo, aprimora a recuperação da modulação autonômica cardíaca. No segundo estudo, investigamos se o treinamento específico de curta duração, a pré-temporada, seria capaz de influenciar a recuperação autonômica cardíaca de jogadores de futsal. Foram avaliados nove jogadores de futsal, antes e após a prétemporadade quatro semanas. Neste estudo, avaliamos a recuperação do tônus vagal, identificada pela frequência cardíaca de recuperação (FCrec) e da modulaçãoautonômica cardíaca, identificada pela recuperação da variabilidade da frequência cardíaca (recVFC).A FCrec foi avaliada através dos valores absolutos de cada 30 segundos, enquanto que a recVFC foi avaliada pelo índice LnRMSSD2-5min. Observou-se que, após a pré-temporada, os atletas diminuíram a FCmáx em 7 bpm, diferença que foi percebida em quase todos os cinco minutos da recuperação. Além disso, a recVFC melhorou após a prétemporada o LnRMSSD2-5min no início da pré-temporada era de 1,00 ± 0,45 ms e passou para 1,29 ± 0,63 ms ao final da pré-temporada. Concluiu-se que a pré-temporada de treinamento específico e de curta duração em jogadores de futsal melhorou a recuperação autonômica cardíaca. / Indoor soccer is an intermittent sport with many pauses and substitutions during the match, which allows the recovery of physiological parameters during these moments, providing the player, to play at high intensity. The recovery process after the exercise is mediated by complex physiological phenomena. Due to the diversity of physiological phenomena involved in the recovery cardiac autonomic such as catecholamines, lactate concentration, pH, ammonia, temperature, plasma volume, etc. This parameter has been used as an indicator of recovery in sports. It is known that factors such as aerobic fitness and training influence the cardiac autonomic recovery. This dissertation focused on the study of cardiac autonomic recovery of indoor soccer players. In the first study, we investigated the influence of the coverage indoor soccer training on the recovery of cardiac autonomic modulation. Participated for the study indoor soccer players and active individuals with similar fitness level of athletes with VO2max of 49.4 ± 3.4 and 50.1 ± 5.8 ml.kg.min-1, respectively. We evaluated the recovery of cardiac autonomic modulation in the first five minutes of recovery using the index RMSSD30s normalized index related to vagal activity. It was observed that the soccer players showed recovery of autonomic modulation greater than active individuals from the 90 s recovery (LnRMSSD30s 0.84 ± 0.43 and 0.64 ± 0.17 ms respectively). In this study it was also noted that the soccer players showed vagal reactivation, as the active subjects had vagal suppression during all five minutes of recovery. We conclude that the training of indoor soccer, due to the dynamics of the game, improves recovery of cardiac autonomic modulation. In the second study, we investigated whether the specific training of short duration, the preseason, could influence the recovery of cardiac autonomic of futsal players. We evaluated nine players of indoor soccer, before and after the preseason of four weeks. In this study, we evaluated the recovery of vagal tone, identified by recovery heart rate (HRrec) and cardiac autonomic modulation, identified by the recovery of heart rate variability (recHRV). The HRrec was evaluated by the absolute values of every 30 seconds, while recHRV was evaluated by the index LnRMSSD2-5min. It was observed that after the preseason, athletes decreased in HRmax 7 bpm, difference has been seen in almost all five minutes of recovery. Moreover, recHRV improved after the preseason LnRMSSD2-5min early preseason was 1.00 ± 0.45 ms and increased to 1.29 ± 0.63 ms at the end of the preseason. It was concluded that specific and short-period preseason training in indoor soccer players improved cardiac autonomic recovery.
22

La régulation autonome du myocarde et les performances cognitives sont-elles des outils valides de prévention du surentraînement ?

Dupuy, Olivier (OD) 04 1900 (has links)
Ce travail a été réalisé en cotutelle. / Le syndrome du surentraînement survient généralement suite à un haut degré de stress, associé ou non, au stress de l’entraînement et à un manque certain de repos et de récupération. La manifestation d’un tel syndrome peut être lourd de conséquences tant sur le plan médical que sur le plan social et économique. Il est donc important à ce jour, de valider des outils de prévention pertinents. Plusieurs théories ont donc tenté de déterminer l’avènement du surentraînement et d’en extraire des outils de prévention valides. Néanmoins, nos connaissances à ce sujet restent encore parcellaires. Malgré tout, deux axes de recherches nous permettraient d’accéder à des outils non-invasifs et accessibles. Les mesures de la régulation autonome du myocarde semblent être, depuis les résultats très encourageants de Bosquet et al (2008), des outils très prometteurs. De même, l’utilisation des performances cognitives pourraient être des outils très intéressants dans la prévention du surentraînement (Nederhof et al. 2006, Dupuy et al. 2010). Dans une perspective holistique, le modèle de Thayer et al (2009), nous permettrait d’intégrer l’utilisation combinée des performances cognitives aux indices de la variabilité de la fréquence cardiaque. Dans une démarche de validation il est également nécessaire de connaitre la sensibilité de ces techniques. Or à ce jour la reproductibilité des indices de la réactivation parasympathique ; technique relativement récente, ne sont pas connues. De même, il est important de faire la distinction entre la fatigue aiguë induite par une séance d’entraînement et une fatigue plus chronique. Si les relations entre fatigue aiguë et régulation autonome du myocarde sont bien connues, les relations avec la cognition, sont relativement moins claires. Les deux premières études de cette thèse, vont donc s’intéresser à connaitre la reproductibilité de indices de la réactivation parasympathique et les effets de la fatigue aiguë induite par un exercice sur la cognition associée au contrôle autonome du cœur. Les résultats nous montrent que les indices de la réactivation parasympathique sont moyennement reproductibles, nécessitant une attention toute particulière sur la standardisation de leurs mesures. Par ailleurs, bien que la fatigue induite par l’exercice, produise des désordres d’ordre physiologique, les performances cognitives semblent relativement stables. Apres avoir vérifié ces points d’ordre technologique et méthodologique, il était intéressant de vérifier l’effet d’une surcharge d’entraînement sur les outils retenus, afin d’apprécier leur sensibilité aux effets d’une fatigue chronique. Les résultats nous montrent à la fois l’intérêt d’utiliser les mesures de la variabilité de la fréquence cardiaque ainsi que les mesures de la réactivation parasympathique. Ces deux mesures semblent sensibles aux variations de la charge d’entraînement ainsi qu’à l’état de fatigue des sportifs. Tout aussi intéressant, les performances cognitives semblent également nous permettre de prévenir un état d’intolérance à l’entraînement. Ce travail de thèse trouve toute sa légitimité car il s’inscrit dans une logique d’amélioration de la santé et de prévention du dépassement voire du surentraînement chez le sportif. Les résultats issus de ce travail de thèse, nous permettent d’apporter de nouveaux outils de prévention ainsi que des recommandations quant à leur utilisation. / Overtraining syndrome usually occurs due to a high degree of stress, associated or not, the stress of training and a certain lack of rest and recovery. The demonstration of such a syndrome can have serious consequences both medically and socially and economically.It is therefore important to date to validate relevant prevention tools. Several theories have attempted to determine the advent of overtraining and extract valid prevention tools.Nevertheless, our knowledge on this subject are still patchy. Nevertheless, two lines of research would allow us to access non-invasive tools and accessible. Measures of autonomic regulation of the myocardium seem to be, from the very encouraging results of Grove et al (2008), tools very promising. Similarly, the use of cognitive performance could be very interesting tools in the prevention of overtraining (Nederhof et al. 2006, Dupuy et al. 2010). From a holistic perspective, the model of Thayer et al (2009), we would integrate the combined use of cognitive performance indices of heart rate variability. In a process of validation is also necessary to know the sensitivity of these techniques. Yet to date the reliability of the indices of parasympathetic reactivation; relatively new technique, are not known. Similarly, it is important to distinguish between acute fatigue induced by a workout and more chronic fatigue. If the relationship between acute fatigue and autonomic regulation of the myocardium are well known, the relationship with cognition, are relatively less clear. The first two studies in this thesis are therefore interested to know the reproducibility of indices of parasympathetic reactivation and effects of acute fatigue induced by exercise on cognition associated with the autonomous control of the heart. The results show that the indices of parasympathetic reactivation are moderately reproducible, requiring special attention on the standardization of measurements. Moreover, although fatigue induced by exercise, produce physiological disorders, cognitive performance appear relatively stable. After checking these points technological and methodological, it was interesting to test the effect of overload training on the tools used in order to assess their sensitivity to the effects of chronic fatigue. The results show both the value of using measures of heart rate variability and measures of parasympathetic reactivation. These two measures appear sensitive to changes in training load and to the fatigue of athletes. Equally interesting, cognitive performance also appear to us to prevent a state of intolerance in training. This thesis finds its legitimacy because it is a logical improvement of health and prevention of overtraining or even exceeded in athletes. The results of this thesis, we can provide new tools for prevention and recommendations for their use.
23

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
24

Evolução temporal da pressão arterial e de alterações vasculares em SHR jovens durante o estabelecimento da hipertensão: o efeito do treinamento. / Time-course changes of blood pressure and vascular remodeling in young shr during the stablishment of hypertension: effects of low intensity aerobic training.

Pinheiro, Raul Henrique Oliveira 02 September 2015 (has links)
Estudos na fase crônica da hipertensão comprovam a eficácia do treinamento aeróbio (T) em reduzir parcialmente a pressão arterial (PA), no qual correlacionavam-se com o remodelamento vascular. Pouco se sabe sobre o potencial efeito benéfico do T iniciado em fase pré-hipertensiva. Os objetivos foram analisar em SHR jovens (4 semanas) e seus controles WKY os efeitos sequenciais do T sobre níveis de PA, alterações vasculares, conteúdo de colágeno total, associando-as à modulação neural. Animais em fase pré-hipertensiva realizaram T de baixa intensidade (50-60%) ou sedentarismo por 8 semanas. Foram avaliados os parâmetros funcionais e seus componentes espectrais, alterações estruturais ocorridas em artérias (femoral e renal), arteríolas (músculo sóleo e temporal) e com conteúdo de colágeno. O T reduziu a PAM no SHR na 4ª e 8ª semana, provocou bradicardia de repouso em ambos os grupos na 8ª, melhorou a variabilidade da FC (WKY e SHR) e impediu o aumento da variabilidade da PAS nos SHR. Hipertensão provocou aumento da razão parede/luz e conteúdo de colágeno em ambas as artérias, T impediu esse aumento na artéria femoral, efeito não foi observado na artéria renal. T impediu a queda da razão parede/luz em arteríolas do músculo sóleo sem efeitos no músculo sóleo. / Studies in the chronic phase of hypertension prove the effectiveness of aerobic training (T) in partially reduce blood pressure (BP), which correlated with vascular remodeling. Little is known about the potential beneficial effect of T started in pre-hypertensive stage. The objectives were to analyze in young SHR (4 weeks) and their WKY controls the sequential effects of T on BP levels, vascular changes, total collagen content, linking them to the neural modulation. Animals in the pre-hypertension stage T made of low intensity (50-60%) or inactivity for 8 weeks. We evaluated the functional parameters and their spectral components, structural changes in arteries (femoral and renal), arterioles (soleus muscle and temporal) and collagen content. OT reduced MAP in SHR at 4 and 8 weeks, caused bradycardia standby in both groups in 8th improved HR variability (WKY and SHR) and prevent the increase of SBP variability in SHR. Hypertension caused ratio increase / wall light and collagen content in both arteries, t prevented this increase in femoral artery, an effect was not observed in the renal artery. T prevented the fall of reason / wall light in arterioles of the soleus muscle without effects in the soleus muscle.
25

Evolução temporal do controle autonômico e respostas cardiovasculares associadas em SHR jovens submetidos ao treinamento aérobio. / Temporal evolution of autonomic control and cardiovascular responses associated in young SHR submitted of aerobic training.

Ruggeri, Adriana 23 November 2016 (has links)
É hipótese que (treinamento) T iniciado na fase pré-hipertensiva possa reduzir a atividade simpática e aumentar a vagal ao coração, melhorando a regulação autonômica nos SHR. Investigamos em SHR e WKY jovens (29 dias) os efeitos do T sobre parâmetros hemodinâmicos, funcionamento dos barorreceptores arteriais, tônus simpático e vagal ao coração e variabilidades, e expressão de neurônios pré-ganglionares vagais (Colina Acetil Transferase, ChAT) nos núcleos dorsal motor do vago (DMV) e ambíguo (NA). Ratos T ou sedentários (S) foram canulados nas semanas 0, 1, 2, 4 e 8, para registros funcionais e remoção dos encéfalos para a quantificação (peroxidade e estereologia). A participação dos aferentes periféricos na modulação dos efeitos do T foi avaliada com a desnervação sinoaórtica (SAD). Os efeitos do T são modulados por baro- e quimiorreceptores. O T precoce corrige a disfunção baroreflexa, reduz a hipertonia simpática, mantém parcialmente a tonicidade de neurônios colinérgicos, aumentando a modulação vagal ao coração e melhorando controle autonômico da circulação. / We hypothesized that aerobic training (T) starting at the pre-hypertensive phase reduces not only the sympathetic activity, but increases vagal outflow to the heart, thus improving autonomic cardiovascular control. We investigated in young SHR and WKY the T-induced effects on hemodynamic parameters, activation of arterial baroreceptor, sympathetic and vagal tone to the heart, and the expression of pre-ganglionic parasympathetic neurons (Choline acetyl transferase, ChAT) in the dorsal motor nucleus of the vagus (DMV) and nucleus ambiguous (NA). Rats (29 days) were T or sedentary (S) and cannulated at weeks 0, 1, 2, 4 and 8. After functional recordings, brains were harvested for quantification of neurons (peroxidase and stereology). The peripheral afferents was evaluated in sinoaortic denervation (SAD). SAD abrogated the improvement of baroreflex control and resting bradycardia in intact SHR-T. T-induced effects were modulated by arterial baro- and chemoreceptors. When started at the pre-hypertensive phase, T corrects baroreflex dysfunction, reduces sympathetic hyperactivity, maintain the tonicity of pre-ganglionic cholinergic neurons thus increasing vagal outflow to the heart and allowing a better autonomic control of the circulation.
26

La régulation autonome du myocarde et les performances cognitives sont-elles des outils valides de prévention du surentraînement ?

Dupuy, Olivier (OD) 04 1900 (has links)
Le syndrome du surentraînement survient généralement suite à un haut degré de stress, associé ou non, au stress de l’entraînement et à un manque certain de repos et de récupération. La manifestation d’un tel syndrome peut être lourd de conséquences tant sur le plan médical que sur le plan social et économique. Il est donc important à ce jour, de valider des outils de prévention pertinents. Plusieurs théories ont donc tenté de déterminer l’avènement du surentraînement et d’en extraire des outils de prévention valides. Néanmoins, nos connaissances à ce sujet restent encore parcellaires. Malgré tout, deux axes de recherches nous permettraient d’accéder à des outils non-invasifs et accessibles. Les mesures de la régulation autonome du myocarde semblent être, depuis les résultats très encourageants de Bosquet et al (2008), des outils très prometteurs. De même, l’utilisation des performances cognitives pourraient être des outils très intéressants dans la prévention du surentraînement (Nederhof et al. 2006, Dupuy et al. 2010). Dans une perspective holistique, le modèle de Thayer et al (2009), nous permettrait d’intégrer l’utilisation combinée des performances cognitives aux indices de la variabilité de la fréquence cardiaque. Dans une démarche de validation il est également nécessaire de connaitre la sensibilité de ces techniques. Or à ce jour la reproductibilité des indices de la réactivation parasympathique ; technique relativement récente, ne sont pas connues. De même, il est important de faire la distinction entre la fatigue aiguë induite par une séance d’entraînement et une fatigue plus chronique. Si les relations entre fatigue aiguë et régulation autonome du myocarde sont bien connues, les relations avec la cognition, sont relativement moins claires. Les deux premières études de cette thèse, vont donc s’intéresser à connaitre la reproductibilité de indices de la réactivation parasympathique et les effets de la fatigue aiguë induite par un exercice sur la cognition associée au contrôle autonome du cœur. Les résultats nous montrent que les indices de la réactivation parasympathique sont moyennement reproductibles, nécessitant une attention toute particulière sur la standardisation de leurs mesures. Par ailleurs, bien que la fatigue induite par l’exercice, produise des désordres d’ordre physiologique, les performances cognitives semblent relativement stables. Apres avoir vérifié ces points d’ordre technologique et méthodologique, il était intéressant de vérifier l’effet d’une surcharge d’entraînement sur les outils retenus, afin d’apprécier leur sensibilité aux effets d’une fatigue chronique. Les résultats nous montrent à la fois l’intérêt d’utiliser les mesures de la variabilité de la fréquence cardiaque ainsi que les mesures de la réactivation parasympathique. Ces deux mesures semblent sensibles aux variations de la charge d’entraînement ainsi qu’à l’état de fatigue des sportifs. Tout aussi intéressant, les performances cognitives semblent également nous permettre de prévenir un état d’intolérance à l’entraînement. Ce travail de thèse trouve toute sa légitimité car il s’inscrit dans une logique d’amélioration de la santé et de prévention du dépassement voire du surentraînement chez le sportif. Les résultats issus de ce travail de thèse, nous permettent d’apporter de nouveaux outils de prévention ainsi que des recommandations quant à leur utilisation. / Overtraining syndrome usually occurs due to a high degree of stress, associated or not, the stress of training and a certain lack of rest and recovery. The demonstration of such a syndrome can have serious consequences both medically and socially and economically.It is therefore important to date to validate relevant prevention tools. Several theories have attempted to determine the advent of overtraining and extract valid prevention tools.Nevertheless, our knowledge on this subject are still patchy. Nevertheless, two lines of research would allow us to access non-invasive tools and accessible. Measures of autonomic regulation of the myocardium seem to be, from the very encouraging results of Grove et al (2008), tools very promising. Similarly, the use of cognitive performance could be very interesting tools in the prevention of overtraining (Nederhof et al. 2006, Dupuy et al. 2010). From a holistic perspective, the model of Thayer et al (2009), we would integrate the combined use of cognitive performance indices of heart rate variability. In a process of validation is also necessary to know the sensitivity of these techniques. Yet to date the reliability of the indices of parasympathetic reactivation; relatively new technique, are not known. Similarly, it is important to distinguish between acute fatigue induced by a workout and more chronic fatigue. If the relationship between acute fatigue and autonomic regulation of the myocardium are well known, the relationship with cognition, are relatively less clear. The first two studies in this thesis are therefore interested to know the reproducibility of indices of parasympathetic reactivation and effects of acute fatigue induced by exercise on cognition associated with the autonomous control of the heart. The results show that the indices of parasympathetic reactivation are moderately reproducible, requiring special attention on the standardization of measurements. Moreover, although fatigue induced by exercise, produce physiological disorders, cognitive performance appear relatively stable. After checking these points technological and methodological, it was interesting to test the effect of overload training on the tools used in order to assess their sensitivity to the effects of chronic fatigue. The results show both the value of using measures of heart rate variability and measures of parasympathetic reactivation. These two measures appear sensitive to changes in training load and to the fatigue of athletes. Equally interesting, cognitive performance also appear to us to prevent a state of intolerance in training. This thesis finds its legitimacy because it is a logical improvement of health and prevention of overtraining or even exceeded in athletes. The results of this thesis, we can provide new tools for prevention and recommendations for their use. / Ce travail a été réalisé en cotutelle.
27

Alterações metabólicas e hemodinâmicas na obesidade visceral em ratos : repercussões na função autonômica

Konrad, Signorá Peres January 2010 (has links)
Principais causas de morbi-mortalidade mundial, as doenças cardiovasculares têm o inicio de sua fisiopatologia em idade precoce e, maior predisposição para seu desenvolvimento na vigência das manifestações clinicas da síndrome metabólica como intolerância à glicose, resistência à insulina, obesidade, dislipidemia e hipertensão. Este trabalho foi conduzido com o objetivo de avaliar o efeito da dieta de cafeteria em ratos, sobre variáveis morfométricas, metabólicas e hemodinâmicas associadas às alterações no controle autonômico. Foram utilizados 32 animais, distribuídos em 2 grupos, com delineamento experimental que compreendeu o tratamento com a dieta (24 semanas) e a coleta dos dados. O modelo experimental usado permitiu observar presença de maior adiposidade abdominal, triacilglicerídeos aumentados caracterizando dislipidemia, aumento da glicemia de jejum e redução da resposta de decaimento da glicose, mostrando aumento da resistência à ação periférica da insulina. Observaram-se também HDL-c mais baixo, similaridade nos valores de pressão arterial e frequência cardíaca e alterações importantes no controle autonômico como, redução da variabilidade da frequência cardíaca, modificação no balanço simpato-vagal em favor da modulação simpática sobre a vagal, e correlação direta com os níveis de triacilglicerídeos. Em conjunto, esses achados demonstraram que a dieta de cafeteria induziu alterações de peso corporal e dos depósitos de gordura visceral (TAB) e muscular (TAM) em ratos normotensos acompanhadas de alterações precoces do sistema nervoso autônomo, identificando-se um papel relevante e precoce desse sistema na fisiopatologia da doença cardiovascular associada à alterações metabólicas. / Cardiovascular disease that has been the leading causes of morbidity and mortality in the global world has the beginning of its pathophysiology in precocious age and, greater predisposition for its development in the validity of the clinical manifestations of the metabolic syndrome as to the glucose intolerance, insulin resistance, dyslipidemia, obesity and hypertension. This study was lead with the objective to evaluate the effect of the cafeteria diet in rats, on morphometric, metabolic and hemodynamic parameters associated with the alterations of autonomic control. Rats (n=32) were distributed in 2 groups, one under cafeteria diet and the other on standard food (24 weeks). At the end of the experimental period data were collected. The treated animals presented bigger abdominal adiposity, increased tryacilglicerides characterizing dyslipidemia and increased of the fasting glycemia. The rate of glucose decay was also reduced showing increased peripheral insulin resistance. It was also observed lower HDL-c levels while values of arterial pressure and heart rate did not change. However significant changes in autonomic control of circulation as reduction of heart rate variability as well as increased sympathovagal balance were also observed. These changes were positively correlated with tryacilglicerides levels indicating that cafeteria diet induced not only alterations of body weight but also of the adipose deposits characterizing visceral (WAT) and muscular fat (BAT). Finally the results suggest that autonomic changes may be the early marker of cardiovascular impairment associated with metabolic illness.
28

Respostas da frequência cardíaca durante o exercício isométrico de pacientes submetidos à reabilitação cardíaca fase III

Leite, Poliana Hernandes 10 June 2009 (has links)
Made available in DSpace on 2016-06-02T20:19:12Z (GMT). No. of bitstreams: 1 2579.pdf: 1151605 bytes, checksum: bbdba1904bf51bc08fc113ee84d13c12 (MD5) Previous issue date: 2009-06-10 / Financiadora de Estudos e Projetos / Cardiovascular responses to different isometric contractions were evaluated in 12 patients (63 ± 11,6 years, mean ± dp) with coronary artery disease and/or risk factors, participants in the cardiac rehabilitation phase III. Heart rate variation (&#916;HR) was evaluated during maximum (CVM, five and ten seconds in duration) and submaximal (CVSM, 30 and 60% of CVM-5, until muscle exhaustion) voluntary contraction, using a handgrip dynamometer. Additionally, the RMSSD (representative index of vagal modulation) was calculated at rest (precontraction), at the last 30 seconds of CVSM and recovery (post-contraction). &#916;HR showed higher values in CVM CVM-10 vs-5 (17 ± 5,5 vs 12 ± 4,2 bpm, p <0.05) and the CVSM-60 vs CVSM -30 (19 ± 5,8 vs 15 ± 5,1 bpm, p <0.05). However, results for CVM-10 showed similar &#916;HR compared to results for CVSM (p> 0.05). RMSSD at rest decreased (p <0.05) during CVSM-30 (30% = 28 ± 17 vs 13 ± 8 ms) and CVSM-60 (60% = 26 ± 18 vs 10 ± 4 ms), but returned to baseline values as the contraction was interrupted. In in patients with coronary artery disease and/or risk factors, low intensity isometric contraction, maintained over long periods of time, presents the same effect on the responses of HR, compared to a briefly high intensity or maximal isometric effort. / As respostas da frequência cardíaca frente à diferentes percentuais de contração isométrica foram avaliadas em 12 pacientes (63 ± 11,6 anos; média±dp) com doença da artéria coronária e/ou fatores de risco para a mesma e participantes de um programa de reabilitação cardíaca fase III. A variação da frequência cardíaca (&#916;FC) foi avaliada durante a contração voluntária máxima (CVM; cinco e dez segundos de duração) e submáximas (CVSM; 30 e 60% da CVM-5, até exaustão muscular) de preensão palmar, utilizando-se um dinamômetro (hand grip). Adicionalmente, o RMSSD dos iR-R em ms (índice representativo da modulação vagal no nó sino atrial) foi calculado em repouso (pré-contração), nos últimos 30 segundos da CVSM e na recuperação (pós-contração). A &#916;FC apresentou maiores valores em CVM-10 vs CVM-5(17 ± 5,5 vs 12 ± 4,2 bpm, p<0,05) e no CVSM-60 vs CVSM -30 (19 ± 5,8 vs 15 ± 5,1 bpm, p<0,05). No entanto, os resultados para CVM-10 mostrou &#916;FC similar quando comparado aos resultados obtidos para CVSM (p>0,05). RMSSD de repouso reduziu (p<0,05) durante a CVSM-30 (30% = 28 ± 17 vs 13 ± 8 ms) e CVSM-60 (60% = 26 ± 18 vs 10 ± 4 ms), mas retornou aos valores basais quando a contração foi interrompida. Em pacientes com doença da artéria coronária e/ou fatores de risco para a mesma, a contração isométrica de baixa intensidade mantida por longos períodos de tempo, apresenta os mesmos efeitos sobre as respostas da FC, quando comparada à atividade isométrica de alta intensidade ou ao esforço isométrico máximo.
29

Avaliação da resposta da frequência cardíaca, da pressão arterial e da variabilidade da frequência cardíaca à contração dos músculos do assoalho pélvico

Bastos, Alana Maria Ferreira Guimarães 25 February 2014 (has links)
Made available in DSpace on 2016-06-02T20:19:23Z (GMT). No. of bitstreams: 1 5764.pdf: 2262686 bytes, checksum: 19925e290e86a08608b11073c73bac3f (MD5) Previous issue date: 2014-02-25 / Universidade Federal de Minas Gerais / To prevent and treat pelvic floor muscle (PFM) dysfunctions, level A of evidence proposes isometric contractions to strengthen these muscles. In literature, there are studies regarding the cardiovascular effects of isometric exercises and the cardiac autonomic regulation in response to these exercises. However, currently there are no studies regarding the cardiovascular response to PFM exercises and the effects of these responses to sympathetic and parasympathetic cardiac modulations. Therefore, the objective of this dissertation was to analyze heart rate (HR) response to a protocol of PFM contractions and the acute effect of the PFM contractions in blood pressure (BP) and sympathetic and parasympathetic cardiac modulations responses and compare these variables to rest conditions before and after the PFM contractions. We evaluated eutrophic women aged between 18 and 80 years, divided in groups according to age. They underwent two protocols; each one containing a series of PFM contractions with monitoring of the PFM contraction pressure, HR, BP and R-R intervals. Both series contained 10 PFM contractions, one series contained contractions lasting 5 seconds with 5 seconds of rest between each contraction and the other series contained contractions lasting 10 seconds with 10 seconds of rest between each contraction. We observed an increase in HR during PFM contractions and an increase in systolic BP immediately after the contractions in the evaluated groups. Regarding the cardiac autonomic regulation, we performed the time domain (RMSSD and SDNN indexes) and frequency domain (low and high frequency spectral components in absolute values) analysis. We observed increase in SDNN and RMSSD indexes during PFM contractions; after frequency domain analysis we observed predominance of vagal modulation in the group containing young women after the series of PFM contractions with 10 seconds and the group consisting of adult and elderly women showed a higher prevalence of sympathetic modulation after series of PFM contraction lasting 5 seconds. The observed variables were within the normal values and returned to basal values as soon as the contractions ended. In conclusion, the proposed protocol of PFM contractions might not represent a cardiovascular risk for healthy women. Moreover, the applied protocol did not changed positively or negatively the cardiac autonomic modulation. / Para a prevenção e tratamento de disfunções dos músculos do assoalho pélvico (MAP) é proposto, com nível de evidência A, a realização de contrações isométricas para fortalecimento desta musculatura. Os efeitos cardiovasculares de exercícios isométricos bem como a modulação autonômica cardíaca em resposta a esses exercícios têm sido estudados na literatura. No entanto, atualmente não existem estudos que avaliem a resposta cardiovascular aos exercícios de contração dos MAP e os efeitos dessas respostas sobre as modulações simpática e parassimpática cardíacas. Sendo assim, os objetivos dessa dissertação foram avaliar a resposta da frequência cardíaca (FC) durante um protocolo de exercícios de contração dos MAP e efeito agudo da contração dos MAP na resposta da pressão arterial (PA) e sobre as modulações simpática e parassimpática cardíacas e comparar estas variáveis às condições de repouso antes e após as contrações. Foram avaliadas mulheres eutróficas com idade entre 18 e 80 anos, divididas em grupos de acordo com a idade. As participantes foram submetidas a dois protocolos, cada um contendo uma série de exercícios de contração dos MAP com registro da pressão de contração da MAP, PA, FC e intervalos R-R. As séries continham 10 contrações dos MAP, uma série conteve 10 contrações com duração de 5 segundos e 5 segundos de repouso entre cada contração e a outra era composta por 10 contrações sustentadas por 10 segundos e 10 segundos de repouso entre cada contração. Foram observados valores maiores de FC durante as contrações dos MAP e de PA sistólica imediatamente após os exercícios nos grupos avaliados. Em relação à modulação autonômica, foram realizadas as análises no domínio do tempo (índices RMSSD e SDNN) e no domínio da frequência (componentes espectrais absolutos de alta e baixa frequência). Observou-se aumento dos índices SDNN e RMSSD durante as contrações dos MAP; após a análise no domínio da frequência foi observada maior predominância da modulação vagal no grupo composto por mulheres jovens após a série de contrações dos MAP com duração de 10 segundos e o grupo constituído de mulheres adultas e idosas apresentou maior predominância da modulação simpática após a série de contração dos MAP com duração de 5 segundos. Os valores observados se mantiveram dentro dos padrões de normalidade e retornaram aos valores basais logo após as contrações. Conclui-se que o protocolo de contrações dos MAP proposto parece não apresentar risco cardiovascular para mulheres saudáveis. Além disso, o protocolo aplicado não alterou positiva ou negativamente a modulação autonômica.
30

Evolução temporal da pressão arterial e de alterações vasculares em SHR jovens durante o estabelecimento da hipertensão: o efeito do treinamento. / Time-course changes of blood pressure and vascular remodeling in young shr during the stablishment of hypertension: effects of low intensity aerobic training.

Raul Henrique Oliveira Pinheiro 02 September 2015 (has links)
Estudos na fase crônica da hipertensão comprovam a eficácia do treinamento aeróbio (T) em reduzir parcialmente a pressão arterial (PA), no qual correlacionavam-se com o remodelamento vascular. Pouco se sabe sobre o potencial efeito benéfico do T iniciado em fase pré-hipertensiva. Os objetivos foram analisar em SHR jovens (4 semanas) e seus controles WKY os efeitos sequenciais do T sobre níveis de PA, alterações vasculares, conteúdo de colágeno total, associando-as à modulação neural. Animais em fase pré-hipertensiva realizaram T de baixa intensidade (50-60%) ou sedentarismo por 8 semanas. Foram avaliados os parâmetros funcionais e seus componentes espectrais, alterações estruturais ocorridas em artérias (femoral e renal), arteríolas (músculo sóleo e temporal) e com conteúdo de colágeno. O T reduziu a PAM no SHR na 4ª e 8ª semana, provocou bradicardia de repouso em ambos os grupos na 8ª, melhorou a variabilidade da FC (WKY e SHR) e impediu o aumento da variabilidade da PAS nos SHR. Hipertensão provocou aumento da razão parede/luz e conteúdo de colágeno em ambas as artérias, T impediu esse aumento na artéria femoral, efeito não foi observado na artéria renal. T impediu a queda da razão parede/luz em arteríolas do músculo sóleo sem efeitos no músculo sóleo. / Studies in the chronic phase of hypertension prove the effectiveness of aerobic training (T) in partially reduce blood pressure (BP), which correlated with vascular remodeling. Little is known about the potential beneficial effect of T started in pre-hypertensive stage. The objectives were to analyze in young SHR (4 weeks) and their WKY controls the sequential effects of T on BP levels, vascular changes, total collagen content, linking them to the neural modulation. Animals in the pre-hypertension stage T made of low intensity (50-60%) or inactivity for 8 weeks. We evaluated the functional parameters and their spectral components, structural changes in arteries (femoral and renal), arterioles (soleus muscle and temporal) and collagen content. OT reduced MAP in SHR at 4 and 8 weeks, caused bradycardia standby in both groups in 8th improved HR variability (WKY and SHR) and prevent the increase of SBP variability in SHR. Hypertension caused ratio increase / wall light and collagen content in both arteries, t prevented this increase in femoral artery, an effect was not observed in the renal artery. T prevented the fall of reason / wall light in arterioles of the soleus muscle without effects in the soleus muscle.

Page generated in 0.0712 seconds