Title: The effect of stretching on maximal muscle performance Objectives: Due to the number of studies, concerning the effect of the muscle stretch on sport performance and their heterogeneity in the term of used parameters, tests and even performing the stretch exercises themselves, it would be desirable, thanks to the importance of this subject, to consolide and evaluate up-to-date knowledge. The goal of this diploma thesis is to compare and assess available literature concerning the effect of muscle stretch during warmup on the sport performance and, ideally, to define the best type of the stretching itself. Method: The diploma thesis is composed as a literature review - an integrative review with exactly defined criteria for the use of available studies. Result : Even with the nonuniformity of parameters used in available studies there is a consensus in most of the used sources, which met the criteria of inclusion in this research, which (the consensus) determinates the dynamic stretching as the form most appropriate for enhancing the following sport performance. Although studies, proving this result, are in their findings quite unanimous, a precise definition of prefered exercises for peforming the dynamic stretching and of its parameters is still missing. Key words: stretching, dynamic,...

The purpose of this study was to determine whether listening to motivational music prior to performing leg extensions and flexions effected peak torque performance. Participants included 23 adults between the ages 18 and 48 years. Participants engaged in three sets of leg extensions and flexions utilizing a Cybex Humac NORM system following a warm-up period consisting of listening to either researcher-selected music, self-selected music, and in silence. Two one-way ANOVAs comparing participants’ data showed significant results in leg flexions performed following warm-up while listening to self-selected music. Significant results were not achieved for leg extensions yet a similar trend was seen providing evidence that listening to self-selected music before performing activities increased level of performance.

Skeletal muscle dysfunction in chronic obstructive pulmonary disease (COPD) is a condition in which peripheral skeletal muscle undergoes myopathic changes which impair muscle function, limit physical performance, and can lead to significant disability. While the etiology of the dysfunction is unknown, this study was conducted to test the hypothesis that chronic hypoxemia leads to alterations in oxygen transport and muscle function. A primary objective was to validate elastase-induced emphysema in rats as an animal model of skeletal muscle dysfunction in COPD.Arterial blood gases were used to determine the severity of hypoxemia and sodium dodecyl sulfate- polyacrylamide gel electrophoresis was used to determine the proportions of myosin heavy chain isoforms I, IIa, IIx, and IIb. Measures of microvascular oxygenation and blood flow in the spinotrapezius muscle allowed for determination of both convective and diffusive oxygen supply to the muscle, as well as calculation of muscle oxygen consumption at rest and during electrically stimulated three-minute muscle contractions. Muscle performance measures included peak force, force-time integral, and fatigue index. Due to a presumed rat respiratory virus, which likely resulted in the control group being nearly as hypoxemic as the elastase-induced emphysema group, this study was not able to definitively test the hypothesis that chronic hypoxemia leads to both a diminished supply and demand of oxygen in skeletal muscle. Although many of the results of the present study were not statistically significant, they exhibited consistent trends over time and are likely of physiological significance. All measures of muscle performance were lower in the emphysema group. In addition, spinotrapezius muscle oxygen consumption and blood flow were lower in the emphysema group. The addition of supplemental oxygen during isolated, small-muscle mass exercise did increase the force-time integral by ~18% in both groups, suggesting that muscle work in these hypoxemic animals may be limited by oxygen supply. Thus, the data on muscle fiber type, oxygen consumption and muscle performance suggest that elastase-induced emphysema in rats leads to a similar skeletal muscle dysfunction that is observed in humans with COPD, and indicates that it is a valid animal model of skeletal muscle dysfunction in COPD.

Made available in DSpace on 2014-12-17T14:44:17Z (GMT). No. of bitstreams: 1 AndreOBG_DISSERT.pdf: 1684956 bytes, checksum: c41e79b5cbd9d1d9c025e43fd25d68d0 (MD5) Previous issue date: 2013-09-12 / The objective of this study was to evaluate the effect of low laser power on the performance of anaerobic endurance of the quadriceps muscle in young subjects. Low-level laser therapy (LLLT) appears to decrease some indices of muscle fatigue. Most of these effects may be due to the influence of the laser on the muscles predominantly aerobic. Animal studies and clinical trials have already shown that the laser can improve the efficiency of mitochondrial metabolism for the resynthesis of adenosine triphosphate and thus slow down - or minimize, the deleterious effects of muscle fatigue. This research was characterized as an experimental study of the controlled clinical trial, randomized, blinded, attended by 93 volunteers, military, with ages between 18 and 19 years. The subjects were randomly allocated into three groups: Control (G1), Placebo (G2) and Laser (G3). All volunteers underwent an anthropometric assessment and a protocol Fatigue. This protocol was applied to an initial assessment (AV-1) for the collection of baseline data, and a final evaluation (AV-2). As the study variables, we used the blood lactate concentrations and indices of muscle power, as average power and peak velocity. The fatigue protocol consisted of a test of speed with twenty repetitions, performed on an exercise machine leg press 45? . In conclusion, it was found that, in this study, LLLT caused a significant increase in the Average of the Averages Powers, phase eccentric exercise in leg press 45? performed by young individuals / O objetivo desse estudo foi o de avaliar o efeito da aplica??o do laser de baixa pot?ncia (LBP) sobre o desempenho da resist?ncia anaer?bia do m?sculo quadr?ceps em sujeitos jovens. A terapia com laser de baixa pot?ncia parece diminuir alguns ?ndices da fadiga muscular. A maior parte desses efeitos pode ser consequ?ncia da influ?ncia do laser sobre os m?sculos predominantemente aer?bios. Os estudos em animais e ensaios cl?nicos anteriores mostraram que o laser pode melhorar a efic?cia do metabolismo mitocondrial para a ress?ntese da Adenosina Trifosfato e, assim, retardar - ou minimizar- os efeitos delet?rios da fadiga muscular. Esta pesquisa caracterizou-se como um estudo experimental do tipo ensaio cl?nico controlado, randomizado e cego, no qual participaram 93 volunt?rios, militares, com faixas et?rias entre 18 e 19 anos. Os sujeitos foram alocados randomicamente em tr?s grupos: Controle (G1), Placebo (G2) e Laser (G3). Todos os volunt?rios foram submetidos a uma avalia??o antropom?trica e a um Protocolo de Fadiga. Este protocolo foi aplicado em uma avalia??o inicial (AV-1), para coleta de dados de base, e em uma avalia??o final (AV-2). Como vari?veis do estudo, utilizamos as concentra??es de lactato sangu?neo e ?ndices de pot?ncia muscular, como pot?ncia m?dia e velocidade pico. O protocolo de fadiga consistiu em um teste de velocidade m?xima, com vinte repeti??es, realizado em uma m?quina do exerc?cio leg press 45? . Em conclus?o, verificou-se que, neste estudo, a LBP causou um incremento significativo (p=0,047) na m?dia das pot?ncias m?dias da fase exc?ntrica do exerc?cio leg press 45? realizado por indiv?duos jovens

Made available in DSpace on 2016-06-02T20:19:06Z (GMT). No. of bitstreams: 1 DissKRS.pdf: 1554077 bytes, checksum: dc2648fe7e6c1ab5d89affbf1a2f01be (MD5) Previous issue date: 2007-02-27 / Chronic obstructive pulmonary disease (COPD) is characterized by abnormal inflammation of the lungs in response to inhalation of noxious particles or toxic gases, especially cigarette smoke. COPD presents several systemic effects including nutritional depletion and musculoskeletal dysfunction that cause reduction in exercise tolerance. The aim of this study was evaluate the functional capacity and performance of the respiratory and peripheral muscles and relate them to nutritional status and FEV1. Methods: 12 patients with moderate-severe COPD (70±7 years, FEV1 52±17 % predict, BMI 23±4 kg/m2) and 7 healthy volunteers (69±8 years, FEV1 127±12% predict, BMI 27±3 kg/m2). All of them performed body composition analysis, measuring of maximal respiratory pressure (PImax and PEmax), a symptom-limited cardiopulmonary exercise test (TECR), evaluation of upper limbs force, peak torque and total work of the quadriceps femoral. Results: Patients with COPD had lower values of free-fat mass (FFM) index (18±1 versus 21±1 kg/m2, p≤0,05), maximal load in the TECR (60±20 versus 102±18 watts, p≤0,01), PImax (58±19 versus 87±21 cmH2O, p≤0,05), upper limb force (38±6 versus 47±5 kg, p≤0,05), peak torque (103±21 versus 138±18 N.m, p≤0,05) and total work of the quadriceps femoral (1570±395 versus 2333±568 J, p≤0,05) when compared with control group (test t-Student non-paired). It wasn t found correlation between FEV1 and the variables studied, and FFM index was correlated with the total work of the quadriceps (Pearson, r= 0,6290, p≤0,05). Conclusion: This results point to that patients with COPD show weakness of the inspiratory and peripheral muscles and a reduced functional capacity compared to a ix healthy group. Besides, it suggests that airflow limitation is not a good predictor to quantify nutritional and muscular debilities of patients with COPD. / A doença pulmonar obstrutiva crônica (DPOC) é caracterizada por uma inflamação anormal dos pulmões em resposta à inalação de partículas e/ou gases tóxicos, especialmente a fumaça de cigarro. Tem sido considerada uma doença sistêmica por desencadear diversas manifestações no organismo que incluem a depleção nutricional e a disfunção dos músculos esqueléticos contribuindo para a intolerância ao exercício. O objetivo deste estudo foi avaliar a tolerância ao exercício e o desempenho da musculatura respiratória e periférica e correlacioná-los com o estado nutricional e volume expiratório forçado no 1° segundo (VEF1). Métodos: Foram avaliados 12 pacientes do sexo masculino com DPOC moderada a grave (70 ± 7 anos, VEF1 de 52 ± 17 % previsto, IMC de 23 ± 4 kg/m2) e 7 indivíduos saudáveis (69 ± 8 anos, VEF1 de 127 ± 12% previsto, IMC de 27 ± 3 kg/m2). Todos os sujeitos realizaram análise da composição corporal pela bioimpedância, medida da força muscular respiratória (PImax e PEmax) por manovacuometria, teste de exercício cardiorrespiratório (TECR) incremental em cicloergômetro, avaliação da força de membros superiores em aparelho do tipo hand-grip, medida do pico de torque a 60°/s e trabalho total do quadríceps femoral a 150°/s através de contrações concêntricas utilizando protocolo recíproco. Resultados: Os pacientes com DPOC tiveram valores reduzidos do índice de massa magra corpórea (IMMC) (18 ± 1 versus 21 ± 1 kg/m2, p≤0,05), da carga máxima atingida no TECR (60 ± 20 versus 102 ± 18 watts, p≤0,01), da PImax (58 ± 19 versus 87 ± 21 cmH2O, p≤0,05), da força de membro superior (38 ± 6 versus 47 ± 5 kg, p≤0,05), do pico de torque (103 ± 21 versus 138 ± 18 N.m, p≤0,05) e do trabalho total do quadríceps femoral (1570 ± 395 versus 2333 ± 568 J, p≤0,05) quando comparado vii com o grupo controle (teste t-Student não-pareado). Não houve correlação entre VEF1 e as variáveis estudadas, o IMMC correlacionou-se com o trabalho total do quadríceps (Pearson, r = 0,6290, p≤0,05). Conclusão: Estes resultados indicam que os pacientes com DPOC apresentam fraqueza muscular inspiratória e periférica e uma menor capacidade ao exercício comparado com o grupo saudável e sugerem que a obstrução ao fluxo aéreo não é um bom preditor para quantificar as debilidades nutricionais e musculares dos pacientes com DPOC.