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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.
1

Padronização do teste de corrida atada em velocistas : análise da relação entre potência e desempenho em corrida /

Lima, Manoel Carlos Spiguel. January 2007 (has links)
Orientador: Claudio Alexandre Gobatto / Banca: Sergio Augusto Cunha / Banca: Pedro Balikian Junior / Resumo: Dentro do âmbito do treinamento competitivo evidencia-se a necessidade de criar e aperfeiçoar testes que possam ser aplicados no próprio ambiente de treinamento, priorizando a busca da especificidade na avaliação e de variáveis que possam melhor explicar as alterações do desempenho do atleta. Então, surge uma problemática ao avaliar a aptidão anaeróbia em velocistas em função das metodologias e dos protocolos propiciarem difícil aplicação e inespecificidade, principalmente por não possuírem nenhum teste com o movimento específico para esse grupo. Entretanto, destaca-se na literatura alguns testes laboratoriais utilizados para avaliação da aptidão anaeróbia de corredores, dentre os quais estão o Máximo Déficit de Oxigênio Acumulado (MAOD), o teste de Wingate (TW) e os testes de salto vertical (SV). Com isso, o objetivo do estudo foi padronizar o teste de corrida atada (TCA) analisando a validade, reprodutibilidade e confiabilidade. O protótipo criado para o TCA proporciona a obtenção de valores de força e de velocidade durante o teste que, por sua vez, fornecerá parâmetros de potência pico do TCA (PPTCA), potência média do TCA (PMTCA) e do índice de fadiga do TCA (IFTCA). Para tanto, 10 velocistas do sexo masculino (22,0 l 2,8 anos; 68,1 l 8,9 kg; 1,76 l 0,09 m; 8,1 l 3,1 % Gordura) participaram do estudo. Todos os participantes foram submetidos a avaliação antropométrica, teste incremental para determinação do consumo máximo de oxigênio (VO2max) e do limiar anaeróbio (LAn), teste para determinação do MAOD, TW, dois TCA (teste e re-teste) e um esforço máximo na distância de 300 metros (D300m). Através de coletas sangüíneas retirada do lóbulo da orelha após os testes de TW, TCA e D300m, foram determinadas as concentrações pico de lactato sangüíneo ([Lac]p) para cada um dos testes, respectivamente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the competitive training area, it is observed the necessity to create and improve tests that could be applied in its own training environment, prioritizing the search of the specificity in the evaluation and the variables that can explain the changes of the athlete’s performance better. So, we find a problem concerning the anaerobic fitness evaluation in sprinters due to the methodologies and the protocols, mainly because there are no tests with the specific movement for this particular group. However, it is possible to mention some laboratorial tests that are used to verify the anaerobic fitness performance of the runners, which are, the maximal deficit oxygen accumulated (MAOD), the Wingate test (TW) and the tests of vertical jump (VJ). Thereby, the aim of this study is to standardize the tied running test (TRT), analyzing the validity, reproducibility and reliability. The TRT prototype provides the instantaneous strength and speed values during the test that give peak power (PPTRT), mean power (PMTRT) and fatigue index (FITRT) parameters. Therefore, ten male runners (22.0l2.8 years old, 68.1l8.9 kg, 1.76l0.09 m; 8.1l3.1 % Fat) participated in this study. All the subjects were submitted into the anthropometric assessment, incremental test to determination the maximal consume of oxygen (VO2max) and anaerobic threshold (AT), the MAOD determination test, the TW, the two TRT (test and re-test) and maximum effort in 300 meters of distance (D300m). Through blood samples removed from the earlobe after the TW, TRT and D300m tests, the blood peak lactate concentration ([Lac]peak) was determined in each test, respectively, [Lac]peakTW, [Lac]peakTRT and [Lac]peakD300m. The tests were separated with intervals of 24 to 72 hours. The data were presented in mean and stand deviation (M l SD)...(Complete abstract click electronic access below) / Mestre
2

Efeitos da duração da carga sobre o estresse psicobiológico, demanda energética e lipólise em sessões de musculação realizadas na intensidade de 70% 1RM /

Campanholi Neto, Jose. January 2019 (has links)
Orientador: Vilmar Baldissera / Resumo: A organização das variáveis do exercício resistido altera respostas do estresse psicobiológico, da demanda energética, predominância do substrato energético utilizado durante a prática do exercício e também de lipólise. Desta maneira é fundamental estudar os efeitos das variáveis do exercício resistido sobre as respostas citadas. Os estudos sobre as respostas ao estresse provocado pelo exercício resistido estão voltados, principalmente, para o volume e intensidade. Outra variável pode influenciar sobre estas respostas, a duração da carga. Assim os objetivos deste estudo são: a) Verificar a influência da duração da carga sobre o estresse psicobiológico; b) Avaliar as respostas da demanda energética a diferente duração de carga; c) Determinar o substrato energético predominante durante a execução dos protocolos; d) Investigar o efeito da duração da carga sobre a lipólise. Participaram da pesquisa 16 voluntários do sexo masculino com mais de três meses de pratica em musculação, portanto familiarizados com os exercícios convencionais de academias propostos neste trabalho, com idade média de 29,31 ± 5,26 anos, saudáveis, sem diagnósticos de doenças que impossibilitem a prática de atividade física. Os participantes visitaram o laboratório em cinco ocasiões: na primeira assinaram o TCLE, ocorreu a aplicação do PAR-Q e teste de 1RM em todos exercícios que constituem as sessões. Na segunda visita foi realizada a familiarização com os procedimentos experimentais. Na terceira e quarta v... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The organization of the variables of the resistance exercise changes the responses of psychobiological stress, energy expenditure, predominance of the energy substrate used during exercise and lipolysis. In this way it is fundamental to study the effects of the variables of the resistance exercise on the cited answers. Studies on the responses to stress caused by resistance exercise are mainly focused on volume and intensity. Another variable can influence on these responses is the time under load. Thus the purpose of this study was: a) To verify the influence of the time under load on the psychobiological stress; b) Evaluate the responses of the energy expenditure to different time under load; c) Determine the predominant energy substrate during the execution of the protocols; d) Investigate the effect of the time under load on lipolysis. Sixteen male subjects with more than three months of practice in bodybuilding participated in the study, so they were familiar with the conventional exercises of academies proposed in this project, with a mean age of 29.31 ± 5.26 years, healthy, without diagnoses of diseases that make it impossible the practice of physical activity. The subjects visited the laboratory on five occasions: the first one signed the informed consent, the application of the PAR-Q and the 1RM test occurred in all exercises that constitute the sessions. During the second visit, familiarization with the experimental procedures was performed. In the third and fourth ... (Complete abstract click electronic access below) / Doutor
3

Padronização do teste de corrida atada em velocistas: análise da relação entre potência e desempenho em corrida

Lima, Manoel Carlos Spiguel [UNESP] 09 February 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-09Bitstream added on 2014-06-13T20:10:03Z : No. of bitstreams: 1 lima_mcs_me_rcla.pdf: 2267744 bytes, checksum: 3e5de7b75b382e805164ebdf2da33ff5 (MD5) / Dentro do âmbito do treinamento competitivo evidencia-se a necessidade de criar e aperfeiçoar testes que possam ser aplicados no próprio ambiente de treinamento, priorizando a busca da especificidade na avaliação e de variáveis que possam melhor explicar as alterações do desempenho do atleta. Então, surge uma problemática ao avaliar a aptidão anaeróbia em velocistas em função das metodologias e dos protocolos propiciarem difícil aplicação e inespecificidade, principalmente por não possuírem nenhum teste com o movimento específico para esse grupo. Entretanto, destaca-se na literatura alguns testes laboratoriais utilizados para avaliação da aptidão anaeróbia de corredores, dentre os quais estão o Máximo Déficit de Oxigênio Acumulado (MAOD), o teste de Wingate (TW) e os testes de salto vertical (SV). Com isso, o objetivo do estudo foi padronizar o teste de corrida atada (TCA) analisando a validade, reprodutibilidade e confiabilidade. O protótipo criado para o TCA proporciona a obtenção de valores de força e de velocidade durante o teste que, por sua vez, fornecerá parâmetros de potência pico do TCA (PPTCA), potência média do TCA (PMTCA) e do índice de fadiga do TCA (IFTCA). Para tanto, 10 velocistas do sexo masculino (22,0 l 2,8 anos; 68,1 l 8,9 kg; 1,76 l 0,09 m; 8,1 l 3,1 % Gordura) participaram do estudo. Todos os participantes foram submetidos a avaliação antropométrica, teste incremental para determinação do consumo máximo de oxigênio (VO2max) e do limiar anaeróbio (LAn), teste para determinação do MAOD, TW, dois TCA (teste e re-teste) e um esforço máximo na distância de 300 metros (D300m). Através de coletas sangüíneas retirada do lóbulo da orelha após os testes de TW, TCA e D300m, foram determinadas as concentrações pico de lactato sangüíneo ([Lac]p) para cada um dos testes, respectivamente... / In the competitive training area, it is observed the necessity to create and improve tests that could be applied in its own training environment, prioritizing the search of the specificity in the evaluation and the variables that can explain the changes of the athlete s performance better. So, we find a problem concerning the anaerobic fitness evaluation in sprinters due to the methodologies and the protocols, mainly because there are no tests with the specific movement for this particular group. However, it is possible to mention some laboratorial tests that are used to verify the anaerobic fitness performance of the runners, which are, the maximal deficit oxygen accumulated (MAOD), the Wingate test (TW) and the tests of vertical jump (VJ). Thereby, the aim of this study is to standardize the tied running test (TRT), analyzing the validity, reproducibility and reliability. The TRT prototype provides the instantaneous strength and speed values during the test that give peak power (PPTRT), mean power (PMTRT) and fatigue index (FITRT) parameters. Therefore, ten male runners (22.0l2.8 years old, 68.1l8.9 kg, 1.76l0.09 m; 8.1l3.1 % Fat) participated in this study. All the subjects were submitted into the anthropometric assessment, incremental test to determination the maximal consume of oxygen (VO2max) and anaerobic threshold (AT), the MAOD determination test, the TW, the two TRT (test and re-test) and maximum effort in 300 meters of distance (D300m). Through blood samples removed from the earlobe after the TW, TRT and D300m tests, the blood peak lactate concentration ([Lac]peak) was determined in each test, respectively, [Lac]peakTW, [Lac]peakTRT and [Lac]peakD300m. The tests were separated with intervals of 24 to 72 hours. The data were presented in mean and stand deviation (M l SD)...(Complete abstract click electronic access below)
4

Deguonies suvartojimo atliekant sunkėjantį krūvį pastovios fazės sąsaja su anaerobiniu pajėgumu / Oxygen consumption during increasing load constant phase interface with anaerobic capacity

Pukelevičiūtė, Asta 28 June 2011 (has links)
Pagrindiniai trys faktoriai lemiantys bėgikų ištvermę yra: maksimalus deguonies suvartojimas (MDS), laktato slenkstis (LS), bei bėgimo ekonomiškumas. Geriausi sportininkai turi panašų MDS, LS, bėgimo ekonomiškumą, bet įrodyta, kad raumenų faktoriai gali įtakoti ištvermę labiau, nei MDS. Yra duomenų, kad sportininkų raumenų galingumą įtakoja anaerobiniai adenozintrifosforo rūgšties (ATP) resintezės procesai, kurie gali turėti įtakos ir aerobinės ištvermės sportininkų varžybų rezultatams. Nustatyta, kad nuosekliai sunkėjančio krūvio (NSK) testo pabaigoje yra didesnis anaerobinis ATP resintezės indėlis. Vadinasi, didesnė raumenų masė ir jėga gali padėti toleruoti vis didėjantį ATP pareikalavimą ir parodyti didesnį deguonies suvartojimo pastovios fazės pasireiškimą. Labai įdomu būtų sužinoti, kaip anaerobinis pajėgumas gali įtakoti ilgų nuotolių bėgikų deguonies suvartojimo pastovios fazės trukmę. Mes manome, kad mūsų gauti tyrimo duomenys, leis geriau suprasti, kokį indėlį anaerobinis pajėgumas vaidina skirtingos deguonies suvartojimo pastovios fazės trukmės pasireiškime. Tyrimo tikslas – Nustatyti deguonies suvartojimą atliekant sunkėjantį krūvį ir pastovios fazės sąsaja su anaerobiniu pajėgumu. Tyrimo objektas: anaerobinio pajėgumo poveikis deguonies suvartojimo kaitai sunkėjančio krūvio metu. Tyrimo uždaviniai: 1. Palyginti aerobinio ir anaerobinio pajėgumo rodiklius tarp bėgikų pasiekiančių ilgesnę ir trumpesnę pastovią fazę. 2. Nustatyti koreliacinį ryšį tarp aerobinių ir... [toliau žr. visą tekstą] / Key words: aerobic capacity, anaerobic test, blood lactate concentration, long – distance runners. The three main factors determining runners endurance are: maximum oxygen consumption, lactate threshold and running economy. However, among the best sportsmen of similar maximum oxygen uptake, lactate threshold and running economy has been shown that muscular factors may influence the endurance more than the maximum oxygen consumption. There is evidence that the athletes' muscle power affects the ATP resynthesis anaerobic processes that may affect the aerobic and endurance sports events. showed that a consistent worsening at the end of the test is more anaerobic ATP contribution resynthesis, thus more muscle mass and strength can help to tolerate the increasing demand of ATP longer a burden, and to show increased oxygen consumption in stable phase of occurrence. It is interesting to learn how to influence the anaerobic capacity for long-distance runners' oxygen consumption in stable phase duaration. Therefore, our survey data to obtain a better understanding of the contribution of anaerobic capacity plays a different oxygen consumption constant phase term occurs. The study objective – identify the oxygen uptake during increasing workload constant phase interface with the anaerobic capacity. The object of the study – anaerobic capacity effects on the oxygen consumption change during increasing exercise load. Study tasks: 1. To compare the aerobicand anaerobic capacity in... [to full text]
5

Acute and Chronic Adaptations To Intermittent and Continuous Exercise in Chronic Obstructive Pulmonary Disease Patients

Sabapathy, Surendran, n/a January 2006 (has links)
The primary aim of this thesis was to develop a better understanding of the physiology and perceptual responses associated with the performance of continuous (CE) and intermittent exercise (IE) in patients with moderate chronic obstructive pulmonary disease (COPD). A secondary aim was to examine factors that could potentially limit exercise tolerance in COPD patients, particularly in relation to the dynamics of the cardiovascular system and muscle metabolism. The results of the four studies conducted to achieve these aims are presented in this thesis. In Study 1, the physiological, metabolic and perceptual responses to an acute bout of IE and CE were examined in 10 individuals with moderate COPD. Each subject completed an incremental exercise test to exhaustion on a cycle ergometer. Subjects then performed IE (1 min exercise: 1 min rest ratio) and CE tests at 70% of peak power in random order on separate days. Gas exchange, heart rate, plasma lactate concentration, ratings of breathlessness, inspiratory capacity and the total amount of work completed were measured during each exercise test. Subjects were able to complete a significantly greater amount of work during IE (71 ± 32 kJ) compared with CE (31 ± 24 kJ). Intermittent exercise was associated with significantly lower values for oxygen uptake, expired ventilation and plasma lactate concentration when compared with CE. Subjects also reported a significantly lower rating of breathlessness during IE compared to CE. The degree of dynamic lung hyperinflation (change in end-expiratory lung volume) was lower during IE (0.23 ± 0.07 L) than during CE (0.52 ± 0.13 L). The results suggest that IE may be superior to CE as a mode of training for patients with COPD. The greater amount of total work performed and the lower measured physiological responses attained with intermittent exercise could potentially allow greater training adaptations to be achieved in individuals with more limited lung function. The purpose of Study 2 was to compare the adaptations to 8 wk of supervised intermittent and continuous cycle ergometry training, performed at the same relative intensity and matched for total work completed, in patients with COPD. Nineteen subjects with moderate COPD were stratified according to age, gender, and pulmonary function, and then randomly assigned to either an IE (1 min exercise: 1 min rest ratio) or CE training group. Subjects trained 3 d per week for 8 wk and completed 30 min of exercise. Initial training intensity, i.e., the power output applied during the CE bouts and during the exercise interval of the IE bouts, was determined as 50% of the peak power output achieved during incremental exercise and was increased by 5% each week after 2 wk of training. The total amount of work performed was not significantly different (P=0.74) between the CE (750 ± 90 kJ) and IE (707 ± 92 kJ) groups. The subjects who performed IE (N=9) experienced significantly lower levels of perceived breathlessness and lower limb fatigue during the exercise-training bouts than the group who performed CE (N=10). However, exercise capacity (peak oxygen uptake) and exercise tolerance (peak power output and 6-min walk distance) improved to a similar extent in both training groups. During submaximal constant-load exercise, the improved (faster) phase II oxygen uptake kinetic response with training was independent of exercise mode. Furthermore, training-induced reductions in submaximal exercise heart rate, carbon dioxide output, expired ventilation and blood lactate concentrations were not different between the two training modes. Exercise training also resulted in an equivalent reduction for both training modes in the degree of dynamic hyperinflation observed during incremental exercise. Thus, when total work performed and relative intensity were the same for both training modes, 8 wk of CE or IE training resulted in similar functional improvements and physiological adaptations in patients with moderate COPD. Study 3 examined the relationship between exercise capacity (peak oxygen uptake) and lower limb vasodilatory capacity in 9 patients with moderate COPD and 9 healthy age-matched control subjects. While peak oxygen uptake was significantly lower in the COPD patients (15.8 ± 3.5 mL·min-1·kg-1) compared to the control subjects (25.2 ± 3.5 mL·kg-1·min-1), there were no significant differences between groups in peak calf blood flow or peak calf conductance measured 7 s post-ischemia. Peak oxygen uptake was significantly correlated with peak calf blood flow and peak conductance in the control group, whereas there was no significant relationship found between these variables in the COPD group. However, the rate of decay in blood flow following ischemia was significantly slower (p less than 0.05) for the COPD group (-0.036 ± 0.005 mL·100 mL-1·min-1·s-1) when compared to the control group (-0.048 ± 0.015 mL·100 mL-1·min-1·s-1). The results of this study suggest that the lower peak exercise capacity in patients with moderate COPD is not related to a loss in leg vasodilatory capacity. Study 4 examined the dynamics of oxygen uptake kinetics during high-intensity constant-load cycling performed at 70% of the peak power attained during an incremental exercise test in 7 patients with moderate COPD and 7 healthy age-matched controls. The time constant of the primary component (phase II) of oxygen uptake was significantly slower in the COPD patients (82 ± 8 s) when compared to healthy control subjects (44 ± 4 s). Moreover, the oxygen cost per unit increment in power output for the primary component and the overall response were significantly higher in patients with COPD than in healthy control subjects. A slow component was observed in 5 of the 7 patients with COPD (49 ± 11 mL·min-1), whereas all of the control subjects demonstrated a slow component of oxygen uptake (213 ± 35 mL·min-1). The slow component comprised a significantly greater proportion of the total oxygen uptake response in the healthy control group (18 ± 2%) than in the COPD group (10 ± 2%). In the COPD patients, the slow component amplitude was significantly correlated with the decrease in inspiratory capacity (r = -0.88, P less than 0.05; N=5), indicating that the magnitude of the slow component was larger in individuals who experienced a greater degree of dynamic hyperinflation. This study demonstrated that most patients with moderate COPD are able to exercise at intensities high enough to elicit a slow component of oxygen uptake during constant-load exercise. The significant correlation observed between the slow component amplitude and the degree of dynamic hyperinflation suggests that the work of breathing may contribute to the slow component in patients with COPD.
6

Trainingsbegleitende Leistungsdiagnostik im Behindertensport Ski alpin / Performance diagnostics in disabled alpine skiing

Wippermann, Friederike 05 October 2011 (has links)
No description available.
7

Associação entre maturação sexual e limiar de lactato em meninas de 10-15 anos / Influence of sexual maturation in lactate threshold in female soccer players

Nicoláo, Ana Lúcia Anauate [UNIFESP] 25 August 2010 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:49:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-25. Added 1 bitstream(s) on 2015-08-11T03:26:10Z : No. of bitstreams: 1 Publico-12694a.pdf: 304264 bytes, checksum: cba6cc96909393802ebc71ea67e960ba (MD5). Added 1 bitstream(s) on 2015-08-11T03:26:10Z : No. of bitstreams: 2 Publico-12694a.pdf: 304264 bytes, checksum: cba6cc96909393802ebc71ea67e960ba (MD5) Publico-12694b.pdf: 2030731 bytes, checksum: d847d011541fe13e0332367b34968461 (MD5) / Os limiares de lactato são utilizados para a avaliação da capacidade aeróbia em diferentes idades. Estudos demonstraram que crianças e adolescentes apresentam menores concentrações sanguíneas de lactato ([la]) para mesma carga de esforço do que adultos. Existem evidências de que isto está relacionado ao desenvolvimento maturacional das mesmas. Objetivo: Verificar a associação entre a maturação sexual e o limiar de lactato de atletas de futebol de 12 a 15 anos de idade. Método: A amostra foi do tipo intencional, não probabilística, com um total de 36 meninas, entre 12 e 15 anos, participantes de escolinhas de futebol da prefeitura da cidade de São Paulo. Foram obtidas da amostra a massa corporal, a estatura e a tomada de dobras cutâneas triciptal e subescapular. A maturação sexual foi feita através da observação direta, por uma médica, do desenvolvimento de órgãos genitais e de pilosidade púbica, por meio de planilhas propostas por Tanner. Para determinação do limiar de lactato foi realizado teste progressivo em pista, onde as jovens realizaram três corridas de 800 metros, com a intensidade do esforço sendo controlada por zonas de frequência cardíaca pré-estabelecidas, com mensurações das [la] no final de cada corrida. Através da interpolação linear foi encontrada a velocidade correspondente a [la] de 2,5 mmol.L-1 (V2,5). Para compreender melhor a natureza das associações entre as variáveis foi utilizada a regressão linear múltipla, tendo como variável dependente o limiar de lactato (V2,5) e como variáveis independentes idade (anos), IMC (kg/m2), estatura (cm) e somatório de dobras cutâneas (mm). Resultados: Em mais jovens, pré-púbere, as variáveis de crescimento e a maturação sexual tem pouca associação com o limiar de lactato. Sendo importante uma ponderação sobre a influência da maturação sexual no limiar de lactato. Conclusão: Levando em consideração a homogeneidade do grupo e o fato de a idade entre 12 e 15 anos ser um período de diversas modificações, o desenvolvimento maturacional, e não a idade cronológica, mostrou uma diferença significante nas variáveis analisadas. / The lactate thresholds are used to assess the aerobic capacity in different ages. Studies show that children and adolescents present less lactate blood concentrations [la] than adults under certain effort loads. There are evidences that this is related to their maturational development. Objective: To verify the association between the sexual maturation and the lactate threshold in some adolescent soccer players ranging from 12 to 15 years old. Method: The sample was related to the intentional and not probabilistic type involving 36 girls, from 12 to 15 years old, members of the soccer schools held by the Mayority of São Paulo. The body weight, height and the sum of two skinfolds – calf and triceps were obtained from the sample. A physician directly observed the sexual maturation of the genitals and pubic hair development through the Tanner index. To determine the lactate threshold a progressive test, a 3 x 800 m in running track, was performed by adolescents, their effort intensity was controlled by pre-established heart rate zones and the [la] were measured at the end of each run. The velocity corresponding to [la] of 2,5 mmol.L-1 (V2,5) was obtained through the linear interpolation. The multiple linear regression was used to better understand the nature of these associations between the variables, considering the lactate threshold (V2,5) as a dependent variable and the age (years), the body weight index (kg/m2), height (cm) and the sum of the skinfolds (mm) as independent variables. Result: The growth variables and the sexual maturation have little association with the lactate threshold in the youngest and pre-adolescent girls. It is important to take in consideration the sexual maturation influence on the threshold lactate. Conclusion: Taking in account the group homogeneity and being the range between 12 and 15 years old a period susceptible to many modifications, the maturational development and not the chronological age showed to be responsible for a significant difference in the analyzed variables. / TEDE / BV UNIFESP: Teses e dissertações
8

Muscle Strength, Acute Resistance Exercise, and the Mechanisms Involved in Facilitating Executive Function and Memory

Nicholas W Baumgartner (17343454) 06 November 2023 (has links)
<p dir="ltr">Past research has extensively explored the benefits of acute aerobic exercise (AE) on memory and executive functions. Additionally, the cross-sectional relationship between muscle strength – a direct outcome of RE – and cognition is unknown, despite the simultaneous onset of muscle and cognitive decline in one’s thirties. However, the effects of acute resistance exercise (RE) on cognition remain understudied, despite the growing popularity of RE and evidence that RE may have distinct effects on cognition.. Therefore, the present study aimed to broaden our understanding of the connection between muscle strength and hippocampal-dependent memory and to investigate the influence of RE on memory and executive function.</p><p dir="ltr">A sample of 125 healthy young adults (18-50 years old) completed this study. On the first day of testing, subjects completed a cognitive battery testing aspects of hippocampal dependent memory, spatial abilities, and working memory, a maximal muscle strength testing session including handgrip strength and one-rep-max testing, and maximal aerobic capacity testing. Subjects completed a bioelectrical impedance assessment (BIA) body scan to measure body composition on Day 2. Day 3 consisted of a randomized controlled trial (RCT), where subjects completed either 42 minute moderate intensity RE (n = 62) or a seated rest (n = 61). Cognitive testing including a memory recognition task, an inhibitory control task, and a working memory task were performed both before and after the intervention. Subjects also completed lactate, blood pressure, and blood draw (only a subset of subjects (n = 59)) before and after intervention.</p><p dir="ltr">The results first revealed that after controlling for known covariates, those with greater handgrip strength performed better on mental rotation tasks (t = 2.14, p = 0.04, Δr2= 0.04), while those with higher upper-body relative strength did better on recognition (t = 2.78, p = 0.01, Δr2 = 0.06) and pattern separation (t = 2.03, p = 0.04, Δr2= 0.04) tasks. Further, while there was no acute effect of RE on memory performance, response times during measures of inhibitory control (t = 4.15, p < 0.01, d = 0.40) and working memory decreased after exercise (t = 7.01, p < 0.01, d = 0.46), along with decreases in P3 latency during the inhibitory control task (t =-5.99, p < 0.01, d = 0.58). Additionally, blood lactate (t =-17.18, p < 0.01, d = 2.06), serum brain derived neurotropic factor (BDNF) (t = -4.17, p < 0.01, d = 0.66), and systolic blood pressure (t = -10.58, p < 0.01, d = 0.99) all increased following RE, while diastolic blood pressure (t = 4.90, p < 0.01,d = 0.50) decreased. Notably, the change in systolic blood pressure (t = -2.83, p = 0.01, Δr2 = 0.06) was associated with improvements in behavioral measures of inhibitory control, changes in lactate (t = -2.26, p = 0.03, Δr2 = 0.04) and systolic blood pressure (t = -3.30, p < 0.01, Δr2 = 0.08) were also related to improved behavioral changes in working memory, and changes in lactate (t = -3.31, p < 0.01, Δr2= 0.08) and BDNF (t = -2.12, p = 0.04, Δr2= 0.08) related to faster P3 latency during inhibitory control. Importantly, these associations between physiological and cognitive changes were consistent across both exercise and rest groups, suggesting that physiological changes were linked to improved cognitive performance regardless of group assignment.</p><p dir="ltr">In conclusion, this study highlights the positive relationships between cross-sectional muscle strength and aspects of memory and spatial abilities, with distinct contributions from handgrip and upper body strength. Furthermore, acute RE was shown to enhance executive functions, particularly in terms of processing speed during inhibitory control (response time and P3 latency) and working memory (response time). This study suggests that RE can be a valid way to garner exercise-induced benefits on executive functions potentially through its influence on lactate, BDNF, and blood pressure, however, since these effects were evident regardless of intervention, more work is needed to determine if RE-induced changes have the same mechanisms. Overall, these findings underscore the potential benefits of muscle strength and RE on enhancing executive function in young and middle-aged adults.</p>

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