Dissertations / Theses on the topic 'Anabolic resistance'

Sarcopenia negatively impacts physical function and health. Although the mechanisms underpinning sarcopenia are unclear, a blunted response to anabolic stimuli is observed. Accordingly, Chapter 2 explored how dose, timing, distribution and source of dietary protein intake differed between healthy young and older individuals. We showed that, whilst the recommended dietary allowance for protein was met by most individuals, total protein intake was lower and unevenly distributed across meals in old. The observation of sub-optimal protein intakes in older individuals has important implications for skeletal muscle maintenance. Therefore, in Chapter 3 we investigated the muscle anabolic response in young lean, old lean and obese old individuals to a suboptimal protein dose. Whilst young lean and, to a lesser extent, old lean significantly increased postprandial myofibrillar protein synthesis (MyoPS), this response was blunted in obese old. Furthermore, MyoPS correlated significantly with step count and leg fat mass in old. Based on the age-related decrease in MyoPS, we assessed the ability of phosphatidic acid (PA) to increase MyoPS at rest and after exercise in Chapter 4. Compared to a placebo treatment, MyoPS was blunted upon PA consumption in the late phase of resistance exercise recovery and was probably due to impaired anabolic signaling.

Purpose: To determine the effect of four postexercise beverages, differing in macronutrient content, on metabolic response to an acute resistance exercise bout.

Methods: Forty male subjects performed five sets of eight repetitions at 80% 1RM for leg press and leg extension, and then consumed one of four postexercise beverages (Placebo, PL: a carbohydrate-electrolyte beverage, CE; or one of two milk-based beverages, MILK 1: 1% chocolate milk; MILK 2: a high protein milk beverage). Indicators of muscle protein synthesis (MPS) were assessed before and 1-hr after consuming a postexercise beverage. Muscle protein degradation (MPD) was examined the day before and the day of exercise.

Results: No significant differences were found among groups in MPS. The resistance exercise bout increased the amount of eIF4E-eIF4G by 4.5% 1-hr postexercise (p<0.05) without affecting the amount of eIF4E-4E-BP1. One hour after beverage consumption, serum total amino acid concentration increased for MILK 1 (p=0.003) and MILK 2 (p<0.001) but decreased for CE (p=0.028) and PL (p=0.276). Consumption of MILK 1, MILK 2, and CE significantly increased circulating levels of serum insulin (p<0.001). Serum growth hormone increased 3-fold as a result of the exercise bout but fell to baseline for all groups by 60 min (p<0.001).

Conclusion: The resistance exercise bout was anabolic as shown by the increase in the active eIF4E-eIF4G complex and serum growth hormone. Consumption of MILK 2 led to the most optimal environment for muscle anabolism; however, none of the experimental beverages influenced the measured indicators of muscle protein translation 1-hr after ingestion.
Master of Science

Ageing is associated with an increase in the risk of cardiovascular (CV) mortality, and this risk is elevated in the presence of cardiometabolic disorders such as coronary artery disease (CAD) and type 2 diabetes (T2D). In addition, ageing and disease can negatively impact other physiological variables that are closely linked to cardiovascular risk such as cardiorespiratory fitness (CRF), skeletal muscle volume and function, metabolic function, psychosocial health and functional performance. Resistance exercise provides a potentially safe treatment modality to address many of these impairments in older adults at high CV risk, while concomitantly addressing a range of other co-morbidities associated with older age such as cognitive impairment, peripheral artery disease, kidney disease, cancer, osteoarthritis, osteoporosis and depression. To evaluate the feasibility of resistance exercise in older adults at high CV risk, the aims of this thesis are threefold; (1) evaluate the effects of resistance training on individuals with existing CAD, (2) evaluate the current implementation of resistance training within cardiac rehabilitation settings in Australia, (3) evaluate the effect of a novel resistance training prescription, high-intensity power training, on CRF and other CV risk factors in high risk individuals with CAD and T2D. Collectively, the chapters within this thesis have presented a comprehensive narrative of the inter-relationship between CRF, body composition, metabolic health, CV disease and ageing, and advanced the understanding of how to approach older adults in a more wholistic and evidence-based way to best optimise health and well-being. We have also demonstrated the important role of resistance training in counteracting the deterioration of metabolic and physiological health attributed to age and disease, and its potential application as a central and vital medicine for older adults with benefits extending beyond those discussed in this thesis.

Twenty untrained men (18-25 y) were assigned to consume either a milk supplement (MILK) or a carbohydrate-electrolyte supplement (CHO) immediately following each resistance workout during a 10 wk resistance training program. Subjects trained 3 d/wk beginning with an intensity of 55% 1-RM and progressing to 97% 1-RM by wk 10. Muscle strength (1-RM), body composition (DEXA) and resting, fasted serum concentrations of total and free testosterone and IGF-1 were measured pre- and post-training. CHO tended to reduce, while MILK increased body weight (P = 0.10). All subjects significantly reduced percent body fat (1.1%) and significantly increased lean body mass (1.21 kg) as a result of the resistance training with no significant differences between treatments. However, MILK tended to increase lean body mass (P = 0.1) more than CHO (1.6 and 0.8 kg, respectively). About 39% of lean mass gain for all subjects was in the leg region, while the arms accounted for about 28% of lean gain. Resistance training also caused a similar significant 44% increase in muscle strength for the seven exercises combined for both groups. Resting total and free testosterone concentrations significantly decreased from baseline values in both groups of subjects (16.7% and 11%, respectively), while resting insulin concentrations significantly increased in all subjects (P<0.01). There were no significant changes in resting, fasted IGF-1 concentrations. In summary, dietary supplementation with a MILK or CHO beverage immediately following resistance exercise resulted in similar changes in muscle strength and hormone concentrations following a 10 wk periodized resistance training program. MILK tended to increase body weight and lean body mass more so than CHO.
Master of Science

Sarcopenia or the involuntary age associated muscle wasting starts in the fourth decade of life and accelerates markedly from the fifth decade. This gradual loss of muscle mass eventually results in an inability of older people to carry out simple daily tasks, instability, is associated with an increased risk of falls and fractures, loss of independence, and reduced quality of life. As the number of older people is growing steadily in our society, this in turn places an increasing burden on health care resources, making the topic of sarcopenia and its consequences an important area for research. Resistance exercise and protein enriched feeding are potent stimulators of MPS and act synergistically to increase the MPS; however, the muscle protein synthetic responses to amino acids are blunted in the elderly in the resting state. Leucine has been shown to be the most potent branched-chain amino acid acting as a signal for accelerating MPS in the resting state. How intensity and duration of resistance exercise can affect MPS and anabolic signalling in the elderly is less well understood. Can leucine enriched protein supplementation coupled with resistance exercise rejuvenate the MPS responses in the elderly? We aimed to answer these questions. The results revealed a sigmoidal dose-response relationship between exercise intensity and the stimulation of MPS in the post absorptive state, with little increase from 20-40% 1RM, then a bigger rise at 60 % of 1 RM with no significant further increase up to 90% 1RM in both the young and the elderly. Both groups showed quantitatively similar increases in phosphorylation of both p70s6K and 4E-BP1, which were maximal for exercise at 60-90% 1 RM at 1 h post exercise, i.e. just before the maximal increase in MPS. However, older men demonstrated a blunted rise in MPS and anabolic signalling activity after exercise, suggesting a general pattern of a reduced protein synthetic response to exercise in the elderly. This may explain, in part the mechanisms through which muscle is lost gradually with ageing. Increasing exercise volume from 3 to 6 sets at 40% and 75% 1RM produced no additional MPS responses in post absorptive young men; however, in older men, it resulted in enhanced MPS and p70S6K responses at both intensities, suggesting that the muscle of older men requires a greater volume of exercise to activate the protein synthetic machinery sufficiently to achieve synthetic responses comparable to those seen in younger men. Exercise, irrespective of intensity and volume caused only short term stimulation in MPS (returned to basal level at 4h post exercise) in the post absorptive state. Leucine supplementation to protein feeding after resistance exercise appeared to overcome age-related anabolic blunting of responses of myofibrillar protein synthesis and p70S6K phosphorylation in skeletal muscle of older men by rejuvenating their synthetic responses. In summary, the results gave a clear indication as to the likely optimal exercise intensity and volume of acute resistance exercise (6 sets of 8-10 reps at 75% 1RM) coupled with optimal amino acid supplementation (leucine supplemented drink containing about 20 g of protein) required to effectively stimulate MPS and anabolic signalling in the elderly for maintenance of muscle mass. This work helps shed light on the pathophysiology of sarcopenia and suggests strategies that could be used to develop effective countermeasures to counteract sarcopenia.

The present study was designed to test the hypothesis that hormone replacement therapy (HRT) and exercise training would be related to differences in resting hormone levels in association with soft tissue composition changes in postmenopausal women. Estrone (E₁), estradiol (E₂), androstenedione (A-4), cortisol, growth hormone (GH) and insulin-like growth factor I (IGF-I) were determined along with estimates of lean soft tissue (LST) and fat mass in total and regional body by dual-energy x-ray absorptiometry in a cross-sectional sample of women on HRT (n = 38) and not on HRT (no HRT, n = 46) and in a 12 month longitudinal data of the effects of exercise training on these variables. Postmenopausal women aged 40-65 years who were on HRT and no HRT were randomized to exercise [HRT (EX+HRT) and no HRT (EX))] and no exercise [HRT (HRT) and no HRT (CONTROL)]. Subjects were further classified in non-obese and obese (>40% fat) resulting in the following groups: no EX (non-obese and obese) and EX (non-obese and obese). Obese HRT had significant higher E₁, E₂, and lower GH than non-obese HRT. IGF-I was lower in obese HRT compared to both non-obese HRT and no HRT. Non-obese HRT had higher cortisol than non-obese no HRT. Exercise training decreased E₁ and E₂ with no effect on GH, IGF-I, A-4 and cortisol. Exercise training without HRT increased total body, arms and legs LST and decreased % fat. Arm LST increased in EX+HRT and in both non-obese EX and obese EX. Leg LST and % fat increased and decreased, respectively, in non-obese EX. The following was concluded from the study: there were no HRT effect on LST: HRT resulted in high E₁, E₂, GH, and cortisol, and low IGF-I; obesity was positively related to E₂ and negatively related to GH and IGF-I; obesity in addition to HRT was associated with a greater decrease in IGF-I; HRT had no beneficial effect on LST gains and fat mass losses resulting from exercise training; our exercise training effectively increased arm LST but not leg LST in the obese; exercise training did not modify E₁, E₂, A-4, cortisol, GH and IGF-I.

Orientador: José Martins Filho
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: A dimensão mais valorizada do corpo, na contemporaneidade, é a aparência, pois o corpo belo, jovem e magro tornou-se objeto de consumo, sendo exaltado, sobretudo, pelos meios de comunicação e pela publicidade. Importantes implicações para a saúde, em decorrência da massificação desse discurso de exaltação do corpo, são sentidas, especialmente, entre os adolescentes. Tais implicações vão dos distúrbios alimentares ao consumo de esteróides anabolizantes. Este culto do corpo, em que estilo, forma, aparência e juventude contam como seus mais importantes atributos, leva-nos a considerar que, atualmente, o corpo pode ser modelado, construído e reconstruído. O objetivo deste trabalho foi o de identificar entre adolescentes do sexo masculino sua relação com a prática de musculação com a finalidade de alteração corporal por meio da utilização dos EAA. Na metodologia utilizou-se um estudo epidemiológico, mediante um corte transversal da população, envolvendo 3150 adolescentes do sexo masculino praticantes de musculação, com idade entre 15 a 20 anos e matriculados em escolas do município de São Paulo, que foi realizado através de questionário investigativo a que os sujeitos foram submetidos após um estudo piloto. Foi feita uma análise descritiva dos resultados entre as variáveis do estudo realizado pelo teste não-paramétrico do Quiquadrado, considerando como intervalo de confiança 95%. Os resultados apontam que os adolescentes apresentaram alto nível de satisfação com sua corporeidade quando há alteração corporal no que diz respeito ao aumento da massa. Os resultados mostram também que a prática de musculação na academia com esse fim tem sido feita sem orientação profissional e tem se caracterizado pela predisposição ao consumo dos EAA. Mesmo afirmando não saber o que são, os adolescentes declaram assumir o risco de utilização com objetivo estético. Na busca pelo corpo perfeito, estes estão associando a prática da musculação à predisposição ao uso dos EAA, tendo na academia o lugar propício para este envolvimento, o que se transforma em um problema de saúde pública em função da sua ausência de conhecimento sobre os efeitos reais do uso dessas substâncias
Abstract: The body's most valued dimension, in contemporary times, is the appearance, whereas the beautiful, young and thin body has become an object of consumption, exalted above all by the media and advertising. Important implications for health, due to the massification of this discourse on the exaltation of the body, affect especially adolescents. These implications range from eating disorders to consumption anabolic steroids. This cult of the body, of which style, form, appearance and youth count as its most important attributes, leads to the conclusion that, currently, the body can be modeled, built and rebuilt. The aim of this work was to identify among adolescent males their relation to the practice of bodybuilding for the purpose of body modification and the use of AAS. As methodology, an epidemiologicalstudy was appliedusing a cross-section of the population involving 3150 bodybuildersmaleadolescents, aged 15 to 20 years enrolled in schools of São Paulo city through investigative questionnaire applied to the subjects after a pilot study. It was made a descriptive analysis of the variables of the study conducted by the nonparametric Chi-square test, considering a confidence interval of 95%. Results have shown that adolescents demonstrated a high level of satisfaction with their corporeality when there is possibility of body change with regard to mass increase. Results have shown yet that the practice of bodybuilding at the gym has been made without professional guidance and is characterized by the predisposition to consumption of AAS. Even claiming not to know what they are, adolescents declare to assume the risk for use with aesthetic goal. It was observed that adolescents, in the search for the perfect body, are associating the practice of bodybuilding with the predisposition for the use of AAS, having the gym as the appropriate place for this involvement, what leads to a public health problem due to their lack of knowledge about the actual effects of using these substances
Doutorado
Saude da Criança e do Adolescente
Doutor em Ciências

Orientador: José Martins Filho
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Os esteróides anabólicos androgênicos (EAAs), são hormônios sintéticos derivados da testosterona e têm sido usados, por muitos atletas, de diferentes modalidades para melhorar a performance esportiva. Além disso, seu uso se estende também entre os adolescentes e jovens com objetivos estéticos. Faltam dados epidemiológicos relacionados ao uso desses hormônios por adolescentes e jovens frequentadores de academias de ginástica, praticantes de treinamento de força, principalmente no Brasil. Diante disso, o objetivo desse trabalho foi desenvolver, padronizar e validar um questionário de uso de esteróides anabolizantes em jovens praticantes de treinamento de força e aplicar o instrumento em população alvo específica. Após a elaboração do instrumento, dez especialistas divididos nas áreas de medicina, educação física, nutrição, fisioterapia e estatística, participaram da primeira etapa de validação, através do método de porcentagem de concordância. Após adequação ou retirada das questões que atingiram concordância inferior a 90%, foi realizada a segunda etapa de teste-reteste em 50 jovens com idade entre 14 à 24 anos. Posteriormente a validação, foram aplicados 560 questionários em jovens entre 14 à 24 anos praticantes de treinamento de força na cidade de Piracicaba, São Paulo, Brasil. Os dados foram inicialmente inseridos no Micosoft Excel for Mac 2011 e analisados através do software SPSS for Windows 20.0. Foi realizado o teste de correlação de Spearman (rs) para avaliação da reprodutibilidade e para a segunda etapa da pesquisa foi usada estatística descritiva e teste do Quiquadrado. Na etapa de validação do instrumento, 30 questões tiveram índice de concordância maior ou igual a 90%, sendo 7 que apresentaram índice menor que 90% foram reformuladas ou retiradas. Os resultados mostram alto nível de reprodutibilidade em cada questão, sendo algumas delas rs= 1,00 (p=0,0001). O menor valor de reprodutibilidade encontrado foi de rs= 0,66 (p=0,0001). Após aplicação do teste do quiquadrado, a prevalência do uso de EAAs foi de 15% para o sexo masculino e de 2,6% para o sexo feminino. A hipertrofia muscular apareceu como objetivo mais prevalente (22,8%), seguido de definição muscular (4,6%), emagrecimento (2,9%) e o menos prevalente a saúde (2,6%). Dentre os hormônios, o mais citado foi Durateston (43%), seguido por Deposteron e Winstrol (34%) e Decanoato de Nandrolona (26%). Já os suplementos alimentares mais citados foram BCAA com 17%, Whey Protein e Hipercalórico com 15%, seguidos por Albumina, Maltodextrina e creatina, todos com 13% de utilização. Nossos dados demonstram que o instrumento desenvolvido para a pesquisa foi válido e reprodutível e que há um número importante de jovens praticantes de treinamento de força na cidade de Piracicaba-SP usuários de hormônios e outras substâncias, sendo considerado um problema de saúde pública e que merece atenção e conduta especial dos profissionais envolvidos na saúde do adolescente
Abstract: The androgenic anabolic steroids (AASs) are synthetic hormones derived from testosterone and they have been used by many athletes of diverse modalities to improve sports performance. Besides that, their use also extends to adolescents and young with esthetic goals. There is a lack of epidemiological data related to the use of those hormones by adolescents and young who attend gyms for gymnastics, who practice resistance training, especially in Brazil. In face of that, the goal of this work was to develop, standardize and validate a questionnaire about the use of anabolic steroids in young resistance trained subjects and apply the instrument in a specific target population. After developing the instrument, ten specialists divided into the areas of medicine, physical education, nutrition, physicaltherapy and statistics participated in the first phase of the validation, by means of the method of agreement percentage. After making adaptations or withdrawing the questions which reached an agreement of less than 80%, there was a second phase of testing-retesting carried out in 50 young, ages 14 to 24 years. Subsequent to the validation, 560 questionnaires were applied to young between 14 to 24 years who practiced resistance training in the city of Piracicaba, São Paulo, Brazil. The data was initially inserted into Microsoft Excel for Mac 2011 and analyzed through SPSS software for Windows 20.0. The Spearman (rs) correlation test was carried in order to evaluate the reproductabilty and for the second phase of the research descriptive statistics and the chi-square test were used. In the validation of the instrument phase, 30 questions had an index of agreement higher or equal to 90%, 7 having evinced an index smaller than 90% were restated or withdrawn. The results evinced a high level of reproducibility in each question, some of them being rs= 1.00 (p=0.0001). The smallest value of reproducibility found was of rs= 0.66 (p=0.0001). After the application of the chi¿square test, the prevalence of use of AAS was of 15% for males and 2.6% females. Muscle hypertrophy appeared as the most prevalent goal (22.8%), followed by muscle definition (4.6%), weight loss (2.9%) and the less prevalent was health (2.6%). Among the hormones, Durateston (43%) was the most cited, followed by Deposteron and Winstrol (34%) and Nandrolone Decanoate (26%). Now the most cited dietary supplements were BCAA with 17%, Whey Protein and Hypercaloric with 15%, followed by Albumin, Maltodextrine and creatine, all with 13% of usage. Our data shows that the instrument developed for the research was valid and reproducible and the is a considerable number of young who practice resistance training in the city of Piracicaba-SP users of hormones and other substances, it being considered a public health problem and which deserves the special attention and conduct of the professionals involved in the health of the adolescent
Doutorado
Saude da Criança e do Adolescente
Doutor em Ciências

Introdução: Os esteroides androgênicos anabolizantes (EAA) são hormônios sintéticos análogos à testosterona, utilizados em homens para tratar o hipogonadismo. Sabendo dos potenciais efeitos tróficos na musculatura esquelética, muitos atletas e frequentadores de academia começaram a autoadministrar estes ergogênicos de forma ilícita e abusiva. Segundo a literatura, o uso abusivo interfere diretamente no sistema nervoso central, com aumento exacerbado da atividade nervosa simpática muscular (ANSM) associado à uma redução do fluxo sanguíneo muscular (FSM) periférico em repouso. Porém, não é conhecido o comportamento reflexo da ANSM e FSM pelo estímulo mecano/metaborreflexo (exercício isométrico) e do comando central (estresse mental) em jovens usuários de EAA. Objetivos: Testar a hipótese de que indivíduos que fazem uso de EAA, apresentam exacerbação da resposta da ANSM e redução do FSM pela via aferente mecanorreflexa e metaborreflexa, bem como, pela via eferente do comando central. Métodos: Foram selecionados 37 voluntários praticantes de treinamento resistido (musculação) por pelo menos 2 anos. Dezenove usuários de EAA (UEAA) por pelo menos 2 anos e 18 não usuários (NUEAA) foram incluídos no estudo. Todos os participantes realizaram anamnese, coleta de urina para análise toxicológica e avaliação da composição corporal por meio da absorciometria de raio-X de dupla energia (DXA). A ANSM foi avaliada pela técnica de microneurografia. O FSM do antebraço foi avaliado pelo método de pletismografia de oclusão venosa. A pressão arterial foi avaliada de forma não invasiva, batimento-a-batimento cardíaco, pelo método oscilométrico (Finometer®) e a frequência cardíaca (FC) foi registrada pelo eletrocardiograma. O estímulo mecano/metaborreflexo foi testado pelo exercício isométrico (preensão de mão) a 30% da contração voluntária máxima durante 3 minutos. O estímulo do comando central foi testado pelo estresse mental (Stroop Color Word Test) durante 4 minutos. Resultados: O grupo UEAA apresentou maior peso corporal (90,7±12,0 vs. 81,0±12,5 kg, respectivamente; p=0,02), índice de massa corporal (29,1± 2,8 vs. 25,3±2,2 kg/m2, respectivamente; p < 0,001) e massa magra (78,1±7,6 vs. 63,0±7,3 kg, respectivamente; p<0,001) quando comparado ao grupo NUEAA. No período basal, observamos maior ANSM (23±6 vs. 15±4 disparos/min; p < 0,001), ANSM/100 batimentos cardíaco (34±9 vs. 24±6 disparos/100bat; p=0,001) e FC (69±6 vs. 61±6 bpm; p < 0,001) no grupo UEAA quando comparado ao NUEAA. Para as demais variáveis hemodinâmicas e neurovasculares no período basal, não foram observadas diferenças significativas. Durante o exercício isométrico, a resposta pico do 3º min da FC (84±8 vs. 76±11bpm; p < 0,05) e PAM (122±14 vs. 113±11 mmHg; p < 0,05) foram maiores no grupo UEAA quando comparado ao NUEAA, entretanto, não houve diferença na resposta da ANSM, ANSM/100bat, FSM e CVA entre os grupos. Durante o estresse mental, a resposta pico do 4º min da ANSM (31±3 vs. 24 ± 5 disparos/min; p < 0,01) e da FC (76±7 vs. 69±10 bpm; p=0,01) foi maior no grupo UEAA quando comparado ao NUEAA. A resposta pico do FSM (3,08±1,16 vs. 4,34±1,57 ml/min/100ml; p < 0,01) e da CVA (3,00±1,29 vs. 4,21±1,25 ml/min/100ml; p < 0,01) foi menor no grupo UEAA quando comparado ao grupo NUEAA. Não houve diferença na resposta da ANSM/100bat entre os grupos. Conclusão: Durante a estimulação mantida de mecano-metaborreceptores, os UEAA apresentaram respostas semelhantes da ANSM, FSM e CVA. No entanto, durante a estimulação do comando central, os UEAA apresentaram ANSM exacerbada e atenuação da resposta vasodilatadora muscular. Dessa forma, o comando central parece ser uma importante via de ativação neural que desencadeia a disfunção vasodilatadora muscular observada em UEAA em situações reacionais de estresse
Introduction: Anabolic androgenic steroids (AAS) are synthetic hormones analogous to testosterone used to treat hypogonadism in men. Assuming the potential trophic effects on skeletal muscle, many athletes have used these illicit drugs abusively. According to the literature, AAS abuse directly interferes with the central nervous system, with an exacerbated increase in muscle sympathetic nerve activity (MSNA) associated with a reduction in forearm blood flow (FBF). However, the reflex response of MSNA and FBF by the mechano/metaboreflex stimulus (isometric exercise) and the central command (mental stress) in young AAS users have never been tested. Objective: To test the hypothesis that AAS abuse would cause an exacerbated MSNA associated with reduced FBF by increasing afferent mecanorreflex and metaboreflex activation and efferent central command response. Methods: We enrolled 37 participants who have been practicing resistance training for at least 2 years. Nineteen AAS users self-administering AAS for at least 2 years (AASU) aged 31±6 yr and eighteen AAS nonusers (AASNU) aged 29±4 yr were included. All participants underwent anamnesis, urine collection for toxicological analysis and body composition assessment using dual energy X-ray absorptiometry (DXA). MSNA was evaluated by microneurography technique and FBF was evaluated by venous occlusion plethysmography. Blood pressure was evaluated non-invasively, beat-by-beat by oscillometric method (Finometer®) and heart rate (HR) was recorded by electrocardiogram. The mechano/metaboreflex stimulus was tested by isometric exercise (handgrip) at 30% of maximal voluntary contraction for 3 minutes. The central command stimulus was tested by mental stress (Stroop color-word test) for 4 minutes. Results: AASU had higher body weight (90.7±12.0 vs. 81.0 ± 12.5 kg, respectively, p = 0.02), body mass index (29.1 ± 2.8 vs. 25.3 ± 2.2 kg/m2, respectively, p < 0.001) and lean mass (78.1 ± 7.6 vs. 63.0 ± 7.3 kg, respectively, p < 0.001) when compared with AASNU. At baseline, we observed higher MSNA (23 ± 6 vs. 15 ± 4 burts / min, p < 0.001), MSNA / 100 beats (34 ± 9 vs. 24 ± 6 burts / 100 beats, p = 0.001) and HR (69 ± 6 vs. 61 ± 6 beats/min, p < 0.001) in AASU compared with AASNU. There were no significant differences for hemodynamic and neurovascular variables at baseline. During isometric exercise, peak HR response at 3rd min (84 ± 8 vs. 76 ± 11bpm, p < 0.05) and median arterial blood pressure (122 ± 14 vs. 113 ± 11 mmHg, p < 0.05) were higher in AASU when compared with AASNU. There were no differences in MSNA response, MSNA / 100 beats, FBF and FVC between groups. During mental stress, peak MSNA response at 4th min (31 ± 3 vs. 24 ± 5 bursts / min, p < 0.01) and HR (76 ± 7 vs. 69 ± 10 beats/ min, p = 0,01) was higher in AASU when compared with AASNU. Peak FBF (3.08 ± 1.16 vs. 4.34 ± 1.57 ml / min / 100 ml, p < 0.01) and FVC responses (3.00 ± 1.29 vs. 4.21 ± 1.25 ml / min / 100 ml, p < 0.01) were lower in AASU compared with AASNU. There was no difference in MSNA / 100 beats response between groups. Conclusions: During sustained mechano-metaboreceptors stimulation, AASU presented similar MSNA, FBF and FVC responses. However, during central command stimulation, AASU presented exacerbated MSNA and blunted FBF. Thus, the central command seems to be an important neural activation pathway that triggers the muscular vasodilator dysfunction observed in AASU in reactive stress situations

The development of lean body mass (LBM) is closely linked to protein feeding. Along with resistance exercise protein feeding, or amino acid provision, stimulate muscle protein synthesis (MPS). Repeated stimulation of MPS above protein breakdown results in lean mass accretion. Many athletes aim to build or maintain LBM. The aim of this thesis was to better understand the relationship between LBM and protein feeding in trained individuals. This aim was studied in the applied setting and at whole body, muscle and molecular level. Chapter 2 revealed differences in total body mass and LBM between young rugby union players competing at different playing standards. Protein consumption was higher in players that played at a higher standard. The protein consumption of players at both playing standards was higher than current protein recommendations for athletes. The Under 20 (U20) rugby union players in Chapter 3 also consumed more protein than current recommendations state. Their dietary habits changed depending on their environment and they consumed more protein while in Six Nations (6N) camp compared with out of camp. Also, there were changes in dietary habits for individuals, however, those changes did not occur at the group level. Using the camp as an education tool for good nutrition habits could be advantageous. As a group, rugby union players’ body composition did not change from pre to post a 6N tournament. However, there was individual variation, which could be meaningful for the individual players. We provide evidence suggesting that in elite sport, athletes should be considered as individuals as well as part of a group if appropriate. The protein ribosomal protein S6 kinase 1 (p70S6K1) is part of the mammalian target of rapamycin complex 1 (mTORC1) pathway, which regulates MPS. The response of p70S6K1 activity was 62% greater following resistance exercise coupled with protein feeding compared with protein feeding alone in Chapter 3. P70S6K1 activity explained a small amount of the variation in previously published MPS data. The activity of the signalling protein p70S6K1 was unchanged in response to different doses of whey protein in Chapter 4 and 5. These data suggest that resistance exercise is a larger stimulus of p70S6K1 activity and when manipulating aspects of protein feeding p70S6K1 activation may be a limited measure. Consumption of 40 g of whey protein stimulated myofibrillar MPS to a greater extent than 20 g after a bout of whole body resistance exercise. The amount of LBM that the trained individual possessed did not influence this observed response. These data suggest that the amount of muscle mass exercised may influence the amount of protein required to increase MPS stimulation. For those engaging in whole body resistance exercise 20 g of protein is not sufficient to maximally stimulate MPS. The athletes in Chapters 2 and 3 of this thesis consumed more protein than current recommendations that do not take into account whole body exercise. Current post-exercise protein recommendations may no longer be optimal given this new information. Future work should directly investigate the MPS response to protein ingestion following resistance exercise engaging different amounts of muscle mass in well trained and elite populations. Identifying the protein dose required for maximal stimulation of MPS following whole body exercise would be an informative area of future research.

Although the long-term therapeutic benefits of exercise are indisputable, contractile activity may induce divergent adaptations in insulin-resistant vs. insulin-sensitive skeletal muscle. The purpose of this study was to elucidate if the anabolic response following resistance exercise (RE) is altered in myocellular sub-fractions in the face of insulin resistance. Lean (Fa/?) and obese (fa/fa) Zucker rats were assigned to sedentary and RE groups and engaged in either cage rest or four lower-body RE sessions over an 8-d period. Despite obese Zucker rats having significantly smaller hindlimb muscles when compared to age-matched lean rats, basal 24-h fractional synthesis rates (FSR) of mixed protein pools were near normal in distally located muscle groups (gastrocnemius, plantaris, and soleus) and even augmented in those located more proximally (P<0.05; quadriceps). Although 2 x 2 ANOVA indicated a significant main effect of phenotype on mixed FSR in gastrocnemius and soleus (P < 0.05), phenotypic differences were partially accounted for by an exercise effect in the lean phenotype. Interestingly, obese rats exhibited a significant suppression of myofibrillar FSR compared to their lean counterparts (P<0.05; gastrocnemius), while synthesis rates of mitochondrial and cytosolic proteins were normal (gastrocnemius and quadriceps), suggesting a mechanism whereby translation of specific mRNA pools encoding for metabolic enzymes may be favored over other transcripts (e.g., contractile proteins) to cope with nutrient excess in the insulin-resistant state. Immunoblotting of the cytosolic fraction in gastrocnemius muscle indicated an augmented phosporylation of eIF4EBP1 (+ 9%) and p70s6k (+85%) in obese vs. lean rats, but a more potent baseline inhibition of polypeptide-chain elongation as evidenced by an increased phospho/total ratio of eEF2 (+78%) in the obese phenotype. Resistance exercise did not improve synthesis rates of myofibrillar, cytosolic, or mitochondrial proteins to the same extent in obese vs. lean rats, suggesting a desensitization to contractile-induced anabolic stimuli in the insulin-resistant state. We conclude that insulin resistance has diverse effects on protein metabolism, which may vary between muscle groups depending on fiber type distribution, location along the proximodistal body axis, and myocellular sub-fraction, and may blunt the anabolic response to voluntary resistance exercise.

碩士
國立臺灣師範大學
體育學系
96
Purpose: This research compared the energy expenditure and hormone concentration after different kinds of contraction speed resistance exercises with the same intensity and total work. Methods: Ten male students (age: 22.5 ± 2.4 years; height: 173.5 ± 4.9 cm; weight: 71.3 ± 4.6 kg) from the Department of Physical Education who have experience in resistance exercise performed two different speeds (fast speed with 2 seconds in concentric contraction and 2 seconds in eccentric contraction, and the duration of the exercise is 16 minutes; slow speed with 4 seconds in concentric contraction and 4 seconds in eccentric contraction, and the duration of the exercise is 32 minutes) of resistance exercise (3 sets, 8 exercises, 45%1RM, and 10 repetitions) by counter-balanced design. The factors which may influence excess post-exercise oxygen consumption (EPOC), energy expenditure, the density of growth hormone, cortisol, and testosterone during and after exercise were observed. Results: In terms of the two contraction speeds, there were no significant differences in heart rate, ventilation, and body temperature during various stages of exercise and after exercise. The fast speed resistance exercise is significantly greater in oxygen consumption than the slow during exercise (p＜.05), but there were no significant differences after exercise. The energy expenditure in slow speed resistance exercise was greater than that of fast speed (p＜.05), but there were no significant differences after exercise. The total amount of EPCO during two hours after exercise and various stages showed no significant differences. Lactic acid, growth hormone, and cortisol were significantly higher after the slow speed resistance exercise than the fast. However, there were no significant differences in testosterone between slow and fast speed resistance exercise. Conclusion: (1) The fast speed resistance exercise was significantly greater in oxygen consumption than the slow speed. It might due to the longer duration of exercise, the energy expenditure in slow speed resistance exercise was greater than that of fast speed. (2) The influence of different speed resistance exercises on energy expenditure was found only during the exercise and the early stage of recovery from exercise. Factors such as heart rate, ventilation, body temperature and lactic acid that influence EPOC in exercise recovery stage showed no significant increase in EPOC. (3) The slow speed resistance exercise provided better environment for fat metabolism and anabolic protein, but that might due to the longer duration of exercise.

博士
中國文化大學
體育學系運動教練碩博士班
99
Purpose: The aim of this study was to investigate the effect of different resistance loads (70% 1RM and 40% 1RM) combined different occlusion pressures (1.3SBP and 0.7SBP) on post-exercise acute anabolic hormone and metabolic stress. Methods: Fifteen healthy males (age: 19.8 ± 1.6yrs; height: 171.1 ± 4.5 cm; weight: 67.3 ± 7.8kg) were recruited in this study to perform bilateral leg extension (5 sets, 12 repetitions with 1min rest among all sets) under five experimental conditions: (1) high intensity resistance exercise (HR, 70% 1RM); (2) low intensity resistance exercise (LR, 40% 1RM); (3) high intensity resistance exercise with low occlusion pressure (HRLO, 70% 1RM + 0.7SBP); (4) low intensity resistance exercise with high occlusion pressure (LRHO, 40% 1RM + 1.3SBP); (5) low intensity resistance exercise with low occlusion pressure (LRLO, 40% 1RM + 0.7SBP). Blood samples were collected prior exercise (pre), and 0, 15, 30, 60 min after exercise (post, post-15, post-30 and post-60) for analysis of growth hormone, testosterone, cortisol, insulin, glucose, lactic acid and pH. The maximal voluntary contraction and electromyography of vastus lateralis were compared at pre and post-60. By counter balance design, each experiment separated by at least 5 days. Results: The GH of HRLO was higher at post, post-15 and post-30 than pre (pre: 0.95 ± 2.07, post: 6.01 ± 6.24, post-15: 4.53 ± 4.51, post-30: 3.44 ±3.23 ng / ml, p > .05). The testosterone of HRLO was higher at post (HRLO: 6.80 ± 1.77, LRHO: 5.82 ± 1.53, LRLO: 5.47 ± 1.18, LR: 5.74 ± 1.48, p < .05) and post-60 (HRLO: 6.35 ± 1.53, LRHO: 5.19 ± 1.17, LRLO: 5.32 ± 1.08, LR: 5.54 ± 1.47, p < .05) than LRHO, LRLO and LR. HRLO also induced higher metabolic stress (LA and pH) and more muscular strength decline (-9.3%). Conclusion: The mode of high intensity resistance loads combined low occlusion pressure could induce higher anabolic hormone response, although higher metabolic stress and more muscular strength decline were also found, but this acute response was the essential fundamental to activate muscle protein synthesis and hypertrophy.

博士
國立臺灣師範大學
體育學系
95
Background: The purpose of this study was to investigate the effects of caffeine and carbohydrate intake on substrate metabolism and acute hormonal responses to a single bout of resistance exercise (RE). Methods: Ten university male students regularly perform RE participated in this study. All subjects performed 1RM test, then performed four treatments:caffeine (CAF, 6mg/kg), carbohydrate (CHO, 1g/kg), carbohydrate+caffeine (CHO＋CAF, 1g+6mg/kg) and control (CON) in counter balance order. All subjects intaked supplement 1 hour prior RE, then, the subjects performed RE (eight exercises, 3 sets of 10 repetitions at 75% of 1RM). Blood samples collected prior supplement intake (pre-60), immediately prior RE (pre-exe), and 0, 15, 30 min after RE (P0, P15, P30) for analysis of testosterone, cortisol, growth hormone, insulin, glucose, free fatty acid and lactic acid. Each experiment separated by 7 days. In this study, statistical analysis of a two-way analysis of variance (treatment by time) with repeated measures was applied. Results: After RE, CHO’s response of GH (P0) and insulin (P0, P15) were significantly higher than CON, the response of testosterone (P0, P15, P30) and cortisol (P0, P15) were significantly lower than CON (p<.05). CAF's response of GH (P0, P15, P30) was significantly lower than CON (p< .05). CHO＋CAF’s response of insulin (P0) was significantly higher than CON, the response of testosterone (P0, P15, P30) was significantly lower than CON (p<.05). Conclusion: The results of this study indicated that intake glucose prior RE increased the response of GH and insulin, decreased the concentration of testosterone and cortisol. Moreover, intake caffeine prior RE inhibited the response of GH. Intake glouse and caffeine prior RE raise the response of insulin and decreased the concentration of testosterone, but no significant effects on GH and cortisol.

FIRST PART: ANIMAL STUDY: Impact of protein intake and high-fat diet on muscle protein synthesis, ectopic lipid infiltration, energy balance and metabolic flexibility in relation to aging in rats Background Ectopic lipid deposition impairs muscle anabolic response especially during aging. We hypothesized that the anabolic efficiency of dietary protein in skeletal muscle might be affected within the context of high-fat diet. Aims The objectives of the study were to investigate muscle protein synthesis, intramuscular lipid deposition, energy balance, and metabolic flexibility in response to two levels of protein intake combined to two levels of fat intake. Methods Two groups of fifty-eight adult and forty-one old male Wistar rats were randomly divided into four groups: isocaloric standard diet (12% protein, 14% lipid, as STD12); isocaloric standard (high-protein) diet (25% protein, 14% lipid, STD25); hypercaloric high-fat (normal-protein) diet (12% protein, 45% lipid, HFD12); and hypercaloric high-fat (high-protein) diet (25% protein, 45% lipid, HFD25). The nutritional intervention lasted 10 weeks. The fractional synthesis (FSR) and absolute synthesis rates (ASR) of mixed muscle proteins were calculated using isotopically labelled C13-valine incorporation in tibialis anterior (TA). Muscle lipid content was assessed using a chromatography-based method. Protein efficiency ratio (PER) was calculated as PER = {100*[weight gain (g)/protein ingested (g)]}. Respiratory exchanges were assessed by indirect calorimetry, and respiratory quotient (RQ) was calculated. Metabolic flexibility and energy homeostasis were evaluated by the analysis of 24h-RQ using the relative cumulative frequency methodology. Results Rats in the high-fat diet groups self-limited their food intake, so that energy intake was not different among the groups. Regardless of dietary intervention, TA muscle weight was lower in old groups compared to their adult counterparts (all p values < 0.01). FSR was lower in old rats fed the HFD25 compared to the old STD12 group (diet effect : p=0.02), whereas FSR in old groups was higher than adult groups (age effect, all p values < 0.05). When considering the ASR, no differences emerged between groups except for a tendency towards higher ASR values in the old HFD12 group than the STD25 group (diet effect: p=0.09). Only old rats in the HFD12 group exhibited increased intramuscular triacylglycerols in TA (age effect : p=0.02 ; diet effect : HFD12 vs. STD 12: 2.04±1.74 vs. 0.83±0.49ug/g, p=0.02). PER was lower in the HFD25 group than the HFD12 group, regardless of age (old rats: 25.5 ± 6.2 vs. 57.4 ± 20.1, adult rats: 30.7 ± 15.9 vs. 78.84 ± 20.9, diet effect, p<0.05). In both adult and old rats, PER was higher in the HFD12 groups than the STD12 and STD25 groups (diet effect, p<0.05). Old rats in the HFD25 group exhibited lower RQ values than the HFD12 group, indicating that they relied more markedly on lipids as substrate for oxidation (RQ: 0.83 ± 0.04 vs. 0.87 ± 0.01, diet effect, p<0.05). The comparison between RQ and FQ indicated that, save in the HFD25 groups, RQ was higher than FQ, suggesting energy storage. Conclusion Aging is characterized by a reduced muscle weight despite an increased FSR, suggesting specific alterations in the nutritional regulation of muscle protein turnover. In isocaloric conditions, higher protein intake modulates muscle lipid infiltration, but does not improve age-related anabolic resistance in old rats fed a high-fat diet. SECOND PART: CLINICAL STUDY: The decline in muscle strength and muscle quality in relation to metabolic derangements in adult women with obesity Background & Aims: Sarcopenic obesity is a clinical syndrome described especially in the elderly in which excess fat and reduced muscularity coexist. The metabolic and functional characteristics related to sarcopenic obesity have not been thoroughly investigated in the early stages of the aging process. The aim of the present study was to investigate the phenotype of sarcopenic obesity- lean body mass, muscle strength and muscle quality in women with and without the Metabolic Syndrome (MetS), and its relationship with the features of myosteatosis. Methods: Study participants were enrolled at the Sapienza University, Rome, Italy. Body composition was assessed by DXA. The Handgrip strength test (HGST) was performed. HGST was normalized to arm lean mass to indicate muscle quality; intermuscular adipose tissue (IMAT) and intramyocellular lipid content (IMCL) were measured by magnetic resonance imaging and spectroscopy, as indicators of myosteatosis. Different indices of sarcopenia were calculated, based on appendicular lean mass (ALM, kg) divided by height squared, or weight, or BMI. The NCEP-ATPIII criteria were used to diagnose the MetS. HOMA-IR was calculated. The physical activity level (PAL) was assessed through the IPAQ questionnaire. Results: 54 women (age: 48±14 years, BMI: 37.9±5.4 kg/m2 ) were included. 54% had the MetS (metabolically unhealthy). HGST/arm lean mass was lower in metabolically unhealthy women than women without the MetS (6.3±1.8 vs. 7.8±1.6, p=0.03). No differences emerged in terms of absolute ALM (kg) or other indices of sarcopenia (ALM/h2 , ALM/weight, or ALM/BMI) between metabolically healthy vs. unhealthy women (p>0.05). Muscle quality (HGST/arm lean mass) was negatively associated with HOMA-IR (p=0.02), after adjustment for age, body fat, hs-CRP levels, and PAL. IMAT, but not IMCL, was significantly higher in obese women with the MetS compared to women without the MetS (p>0.05). No association emerged between HGST/arm lean mass and IMAT or IMCL when HOMA-IR was included in the models. Conclusion: Insulin resistance, and not myosteatosis per se, may play a role in the decline of muscle strength, leading to the phenotype of dynapenic obesity. Dynapenia may precede the decline of lean body mass in metabolically unhealthy obese women.

The simultaneous integration of both endurance and resistance exercise (RE) into a periodised training regime is termed concurrent training. As both exercise modes promote adaptations at both whole-body and skeletal muscle levels that improve oxidative as well as functional capacity, concurrent training is an attractive exercise strategy for improving markers of cardiometabolic health and athletic performance. Since the classic work of Hickson (1980), numerous investigations have shown that concurrent training, relative to resistance training (RT) performed alone, can attenuate improvements in maximal strength, hypertrophy, and indices of power development, with no negative impact on V̇O2max. This has been variously described as the interference effect or concurrent training effect. Despite the majority of the literature supporting the existence of the interference effect, some studies have not observed any evidence of an interference effect, or rather that some adaptations may be more susceptible to interference than others. The equivocal nature of this phenomenon suggests variations in the prescription of individual training variables may modulate the degree of interference seen with concurrent training. Identification of training variables mediating the interference effect will therefore allow for targeted exercise prescription to minimise interference during concurrent training.