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Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / School of Physical Education, Sport, and Exercise Science

The purpose of the present study was to examine the relationship between exercise induced muscle damage and growth factors during two different modes of exercise. Nine healthy untrained male subjects participated in this study and performed two separate single bouts of isokinetic concentric (Con) and eccentric (Ecc) leg extension exercise on the CYBEX NORMT°". The workload was maintained at 75% of 1 RM for each trial, respectively. The maximum sets of 10 repetitions were performed during the Con trial, and the number was also duplicated during the Ecc trial, with 40 seconds of rest between sets. Serum levels of hGH, creatine kinase (CK), and lactic acid were measured, and the CK level was used to determine the degree of muscle tissue damage. A muscle soreness questionnaire was provided to the subjects to assess the degree of quadriceps muscle soreness following each trial. The EMG activity of the rectus femoris and vastus medialis muscles was recorded during each trial. The results of the present study demonstrated no significant differences in hGH output and CK activity between the exercise trials, although there was a significant different lactic acid response (P < 0.05). However, the Con trial produced significant increases (P < 0.05) in hGH and CK levels above the resting value at the post-exercise times. In fact, the 75% Con trial conducted in this study induced an increase in hGH release (peak: 8.23 ± 3.21 ng/ml) that was 2 X higher than a 120% Ecc trial (peak: 3.8 ± 1.2 ng/mI) of the prior study. The results of the present study demonstrate that a single bout of Con resistance exercise at the same intensity (75% of 1 RM), angular velocity, and ROM as a single bout of Ecc exercise can produce greater increases in hGH output and CK response than its Ecc counterpart. This finding does not support the previous results from this laboratory, showing that Ecc exercise is a stronger promoter of hGH output. However, it suggests that the amount of work performed is an important factor for hGH release because the exercise volume applied in the present study was greater than that of the prior study. The CK response of the subjects in this study, as well as the previous work indicate that hGH output is also dependent on exercise that elicits muscle damage. Therefore, the results of the present study suggest that the mode of exercise, Con vs. Ecc, is not as important as the stress placed on the exercising muscle in order to induce optimal muscle hypertrophy. / School of Physical Education

The primary focus of this study was to determine basal levels of myogenic (MRF4, myogenin, MyoD), proteolytic (FOXO3A, atrogin-1, MuRF-1), myostatin, and mitochondrial (PGC-1α & Tfam) mRNA in elderly women before and after aerobic training. This approach was taken to gain insight into the molecular adaptations associated with our observed increases in whole muscle cross sectional area (CSA) (11%, p<0.05), knee extensor muscle function (25%, p<0.05) and aerobic capacity (30%, p<0.05) with training. Nine elderly women (71±2y) underwent muscle biopsies obtained from the vastus lateralis before and after 12-weeks of aerobic training on a cycle ergometer. Post training biopsy samples were acquired 48 hours after the last exercise session. Aerobic training reduced (p < 0.05) resting levels of MRF4 by 25% while myogenin showed a trend to decrease (p = 0.09) after training. FOXO3A expression was 27% lower (p < 0.05) while atrogin-1 and MuRF-1 were unaltered after training. Additionally, myostatin gene expression was decreased (p < 0.05) by 57% after training. Lastly, aerobic training did not alter PGC-1α or Tfam mRNA. These findings suggest that aerobic training alters basal transcript levels of growth related genes in skeletal muscle of older women. Further, the reductions in FOXO3A and myostatin indicate the aerobic training induced muscle hypertrophy in older women may be due to alterations in proteolytic machinery. / School of Physical Education, Sport, and Exercise Science

Access to abstract permanently restricted to Ball State community only. / School of Physical Education, Sport, and Exercise Science

Orientador: Mara Patricia Traina Chacon-Mikahil / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica / Made available in DSpace on 2018-08-04T16:14:31Z (GMT). No. of bitstreams: 1 Santos_ClaudineiFerreirados_M.pdf: 925415 bytes, checksum: ccc25cca6ef6562dc893c089553dd51b (MD5) Previous issue date: 2005 / Resumo: O objetivo do presente estudo foi analisar os possíveis efeitos do treinamento com pesos sobre os indicadores da composição corporal e força muscular após 24 semanas de treinamento com pesos. Vinte e oito indivíduos saudáveis, do sexo masculino, foram divididos em 2 grupos: grupo treinamento (n=14), que foi submetido a 24 semanas de treinamento com pesos e grupo controle (n=14) que se manteve sem qualquer envolvimento com programas regulares de exercícios físicos. Durante o período experimental a composição corporal foi determinada por absortometria radiológica de dupla energia (DEXA). O teste de uma ação voluntária máxima (AVM) foi aplicado como indicador de força muscular em três exercícios (supino em banco horizontal, agachamento e rosca direta de bíceps). O teste t de Student foi utilizado para as comparações entre as características físicas iniciais dos grupos. ANOVA e ANCOVA para medidas repetidas, seguidas pelo teste post hoc de Scheffé, foram utilizadas para o tratamento dos dados. O coeficiente de correlação linear de Pearson foi adotado para estabelecer a correlação entre as modificações das variáveis analisadas. Verificaram-se aumentos significativos na massa corporal e massa isenta de gordura somente para o grupo treinamento (+6,5% e 6,7%, respectivamente). O grupo treinamento aumentou significativamente os indicadores de força muscular em 24%, 31% e 21% (p<0,001), nos exercícios supino, agachamento e rosca direta, respectivamente. A carga absoluta levantada e a carga relativa à massa corporal aumentaram significativamente em 27% e 19,2%, respectivamente (p<0,001). Os resultados indicaram que 24 semanas de treinamento com pesos foram eficientes para gerar modificações importantes na composição corporal e nos indicadores de força muscular neste grupo estudado / Abstract: The objective of the present study was to analyze the possible effects of the weight training on the components of the body composition and the muscular strength after 24 weeks of weight training. Twenty-eight healthy individuals, of the masculine sex, were divided into two groups: group training (n=14), that was submitted to 24 weeks of weight training and group controls (n=14) that stayed without any involvement with regular programs of physical exercises. The body composition was determinated by dual-energy x-ray absorptiometer (DEXA). The test of a maximum voluntary action (AVM) was applied as strength indicator in three exercises (bench press, squat, and arm curl). The test t of Student was used for the comparisons among the initial physical characteristics of the groups. ANOVA and ANCOVA with repeated measures followed by the test post hoc from Scheffé, when p < 0.05, were used for data treatment. Pearson¿s coefficient of linear correlation was adopted to establish the correlation among the modifications of the analyzed variables. Significant increases were only verified in the body mass and lean body mass of fat only for the group training (+6,5% and 6,7%, respectively). The group training increased the muscular strength indicators significantly in 24%, 31% and 21% (p <0,001), in the exercises bench press, squat and arm curl, respectively. The lifted absolute load and the relative load to the body mass increased significantly in 27% and 19,2%, respectively (p<0,001). The results indicated that 24 weeks of training with weights were efficient to generate important modifications in the body composition and in the muscular strength indicators in this studied grou / Mestrado / Ciencia do Desporto / Educação Fisica