A proposta deste estudo foi avaliar o efeito de 8 semanas de treinamento de força ou potência sobre a expressão de genes pertencentes a via de sinalização canônica da WNT, assim como a expressão protéica de b-catenina. Vinte e cinco indivíduos (27,4±4,6 anos) foram distribuídos randomicamente nos grupos: treinamento de força (TF) (n=10), treinamento de potência (TP) (n=10), e controle (C) (n=5). Os grupos TF e TP realizaram o exercício agachamento durante 8 semanas, 3 vezes por semana. Biópsias do músculo vasto lateral foram retiradas antes e após o período de treinamento. Alguns genes foram modulados positivamente no grupo TF (WNT1:6.4 vezesP<0.0001; SFRP1:3.3 vezesP<0.0001 e LEF1:7.3 vezesP<0.0001) e também no grupo TP (WNT1:24.9 vezesP<0.0001; SFRP1:2.7 vezesP<0.0001; LEF1:34.1 vezesP<0.0001 e Cyclina D1:7.7 vezesP<0.001). O conteúdo protéico total de -catenina aumentou somente no grupo TP (p<0,05). Nossos dados indicam que o treinamento de potência desencadeia respostas de maior magnitude sobre a via WNT quando comparado ao treinamento de força máxima. / The purpose of the present study was to evaluate the effects of 8 weeks of strength and power training on the expression of genes related to the canonical WNT pathway and b-catenin protein levels. Twenty five subjects (27.4±4.6 yrs) were randomly assigned to three groups: strength training (ST) (n=10), power training (PT) (n=10), and control (C) (n=5). The ST and the PT groups performed squats, 3 times per week, for 8 weeks. Muscle biopsies from the vastus lateralis muscle were collected before and after the training period. Certain genes were up-regulated in the ST group (WNT1:6.4 foldP<0.0001; SFRP1:3.3 fold-P<0.0001 and LEF1:7.3 foldP<0.0001) and also in the PT group (WNT1:24.9 foldP<0.0001; SFRP1:2.7 foldP<0.0001; LEF1:34.1 foldP<0.0001 and Cyclin D1:7.7 foldP<0.001). Finally, the total protein content of -catenin increased only in the PT group (P<0.05). Our data indicate that PT triggers greater responses on the WNT pathway as compared to ST regimens.

An entire field of research was born when a paper entitled ‘On the education of muscular control and power’ first discussed a “psychical rather than a physical” bilateral adaptation to a unilateral training program. Although the true relevance of this paper would not be recognized for over a century, its novel findings, describing adaptations resulting from physical and skilled training, continue to influence scientific literature to this day. Most notably, Scripture coined the term ‘cross-education’ to describe the improvement in strength or functional performance of not only the trained limb but also in the untrained contralateral limb. Recently, unilateral training or ‘cross-education’ has been highlighted as a possible rehabilitation strategy during recovery from unilateral injuries. However, a number of limitations must be addressed within the scientific literature in order to properly apply unilateral resistance training as an effective rehabilitation strategy. Therefore, the primary goal of this dissertation was to address a number of fundamental issues related to optimizing unilateral resistance training. One such issue is knowledge on the time course of strength increase during unilateral resistance training. The primary purpose of Chapter 2 was to characterize the time-course of strength changes in both the trained and untrained limbs during unilateral handgrip training. Experiment 1 assessed the time-course with a ‘traditional’ training protocol (3x/week for 6 weeks: 18 total sessions) while Experiment 2 assessed a “compressed” protocol in which the number of sessions and contractions were matched but participants trained for eighteen consecutive days. An anticipated outcome was the determination of the minimum number of sessions required to induce contralateral strength gains in the upper limb. A secondary purpose of this study was to examine whether spinally-mediated adaptations in muscle afferent reflex pathways occur after unilateral handgrip training. Experiment 1 indicated six weeks of handgrip training significantly increased force output in both trained and untrained limbs. This strength increase was accompanied by changes in the maximal muscle activation in the trained limb only. Time course data indicated the trained limb was significantly stronger than baseline after the 3rd week of training (session 9) while the untrained limb was stronger after 5 weeks (15 sessions) of unilateral handgrip training. Interestingly, the rate at which strength increased in the untrained limb was similar to the trained side. These strength increases were also accompanied by significant changes in the current needed to produce H@50 in the trained, and Hmax in both the trained and untrained limb indicating alterations in spinal cord excitability. Experiment 2 showed a similar number of sessions was needed to induce significant strength gains in the untrained limb. This indicates training without rest days may be the most efficient protocol within a clinical population when the trained limb is not the focus of recovery. It remains necessary to determine if specific strategies can be employed to optimize unilateral resistance training interventions to increase strength gains. To date, no study has directly assessed the relative contribution of afferent pathways to cross-education. Cutaneous feedback from the skin provides perceptual information about joint position and movement. Unilateral training involves forceful contractions that activate cutaneous receptors in the skin, producing widespread and powerful effects between limbs. Providing “enhanced” cutaneous stimulation during unilateral contractions may alter excitability of interlimb reflex pathways, modifying the contralateral increase in strength. Therefore, the purpose of Chapter 3 was to determine the relative contribution of cutaneous afferent pathways as a mechanism of cross-education by directly assessing if unilateral cutaneous stimulation alters ipsilateral and contralateral strength gains. Participants were randomly assigned to either a voluntary contraction (TRAIN), cutaneous stimulation (STIM), or cutaneous stimulation during voluntary contraction (TRAIN+STIM) group. Each participant completed 6 sets of 8 reps 3x/week for 5 weeks. TRAIN included unilateral maximal voluntary isometric contractions (MVCs) of the wrist extensors. STIM training included cutaneous stimulation (2xRT for 3sec @ 50Hz) of the superficial radial (SR) nerve at the wrist only. TRAIN+STIM included MVCs of the wrist extensors with SR stimulation provided for the duration of the contraction. Two pre-training and 1 post-training session assessed the relative increase in force output during MVCs for wrist flexion, wrist extension and handgrip strength. Results indicated unilateral wrist extension training alone (TRAIN) increased force output in both trained and untrained wrist extensors. Providing ‘enhanced’ sensory feedback via electrical stimulation during training (TRAIN+STIM) led to similar increases in strength in the trained limb compared to TRAIN. However, the major finding revealed that ‘enhanced’ feedback in the TRAIN+STIM group completely blocked interlimb strength transfer to the untrained wrist extensors. It appears the large mismatched sensory volley which was provided may have interfered with the integration of the appropriate sensory cues to the untrained cortex and impaired the ability to induce “cross-education”. It may be possible to enhance effects of training by altering excitability via apparel such as compression garments. Currently, it is unknown whether tactile input to the skin induced via compression apparel may alter transmission of muscle afferent feedback within a limb. Thus, the purpose of Chapter 4 was to examine if sustained input to the skin via compression garment modulates sensory feedback transmission in the upper limb using the Hoffmann (H-) reflex as a probe. The purpose of these experiments was to: 1) explore the effects of compression gear on sensory feedback transmission in the upper limb during a static task, and 2) if the task (locomotor vs. reaching) or phase of a movement differentially modulated this transmission of sensory information. Furthermore, differences in performance of the discrete reaching task were assessed to provide data on whether a compression garment leads to alteration in motor task performance. Combined results from both parts of the study suggest that tactile input provided to the skin via compression garments modulates the excitability of afferent connections independent of descending input. The alteration in excitability occurs across multiple sensory pathways and across multiple movement tasks. Interestingly, there was a significant reduction in the number of errors made during the reaching task, which provides preliminary evidence of an improved performance while wearing a compression garment. Therefore, the compression sleeve appears to increase precision and sensitivity at the joint where it is applied. Overall, these results address many fundamental questions which have previously limited effective translation for rehabilitative interventions. These results provide preliminary guidelines for subsequent strength training interventions to prescribe the optimal ‘dose’ of unilateral strength training to maximize benefits while minimizing intervention burden. These studies also help refine a unifying model of unilateral strength training to include contributions from central motor output as well as afferent feedback. These studies highlight the importance of appropriate sensory feedback during maximal force production and the impact that sensory information from the skin can have on motor output in the nervous system. / Graduate / 0317 / 0719 / 0382

While the benefits of both cardiovascular exercise and resistance training have been well documented, there is a lack of evidence for the order of exercise that is most effective when both are done in the same day. This study was designed to look at two groups of participants performing both resistance (R) and cardiovascular (C) training in the same day to determine if their order, resistance before cardiovascular (R-C) or cardiovascular before resistance (C-R), matter with regard to changes in body composition, maximal strength, and maximal aerobic capacity. The participants were 17 women between the ages of 30 and 55 years, with a BMI of ≥25 or body fat percentage ≥30% and no apparent risk of heart disease. They were randomly assigned into two groups (R-C = 9; C-R = 8) performing 30 minutes of cardiovascular exercise at 60-70% of their estimated VO2MAX and 7 exercises for 3-4 sets of 6 repetitions at their 6-repetition maximum with the R-C group performing the resistance training first and the C-R group performing the cardiovascular training first. There were three days of testing pre- and post-intervention for body weight, percent fat, fat mass, lean body mass, maximal bench press, maximal deadlift, and VO2MAX. There were no significant differences between groups in any of the variables, although there were trends toward significance in the maximal deadlift (R-C +13.5±8.6kg, ES = 1.15; C-R +6.8±5.6kg, ES = 0.42) and VO2MAX (R-C +2.8±2.4 ml/kg/min, ES = 0.41; C-R +0.9±1.0 ml/kg/min, ES = 0.31). Neither group lost significant amounts of body weight. However, there were significant pre- to post-intervention changes in percent fat, fat mass, lean body mass, maximum deadlift, maximum bench press, and VO2MAX for the C-R group and percent fat, fat mass, maximum deadlift, maximum bench press, and VO2MAX for the R-C group. There were also practically significant between group differences with the C-R group improving more in body fat percentage (ES = 0.89) and lean body mass (ES = 0.68) and the R-C group improving more in 1RM deadlift (ES = 1.50) and VO2MAX (ES = 1.57).

Daily undulating periodization represents an increasingly popular trend in exercise science with which a traditional model has been established. Tiered daily undulating periodization pairs the DUP approach with a tiered training system which allows volume and intensity to be more evenly distributed throughout a given graining cycle. The concept of tiered daily undulating periodization is a novel form of periodization and has not been investigated. As such, a comparison of traditional and tiered daily undulating periodization has yet to be examined. Therefore, the purpose of this study was to compare the effects of traditional and tiered daily undulating periodization models as they relate to strength adaptations in trained males. Twenty-seven resistance trained males (22.0 ± 4.5 years) completed an 8 week resistance training protocol. Subjects were randomly assigned to either the traditional daily undulating periodization group (DUP, n = 12) or tiered daily undulating periodization group (TDUP, n = 15). Participants were recruited from the campus recreation center and met the minimum strength requirements of bench pressing their bodyweight, squatting 125% of their bodyweight, and deadlifting 150% of their bodyweight. Strength measures included squat 1RM, bench press 1RM, deadlift 1RM, powerlifting total, and Wilk’s Coefficient. Each variable was measured at baseline and again after the 8 week training period. Each group performed the same number of sets, reps, and exercises throughout each training week. DUP specified all exercises in a given training bout to be performed the same intensity and repetition scheme. TDUP specified performance of one high intensity exercise each day with each subsequent exercise being performed with lower intensity and differing repetition scheme. Data was analyzed via a 2x2 mixed factorial ANOVA with the alpha criterion for significance set at 0.05. There were no significant differences between groups at baseline and no significant differences were observed between groups for total volume or intensity. With respect to strength dependent variables, there was a main effect for time (p = <0.001) for back squat 1RM (DUP pre = 140.5 ± 33.9 kg, DUP post = 163.3 ± 29.8 kg; TDUP pre = 147.3 ±34.0 kg, TDUP post = 166.5 ± 30.7 kg), bench press 1RM (DUP pre = 104.2 ± 12.9 kg, DUP post = 114.9 ± 14.2 kg; TDUP = 110.4 ± 12.7 kg, TDUP post = 120.6 ± 11.9 kg), deadlift 1RM (DUP pre = 177.7 ± 26.4 kg, DUP post = 194.1 ± 20.2 kg; TDUP pre = 169.6 ± 37.5, TDUP post = 188.3 ± 37.5), powerlifting total (DUP pre = 422.4 ± 67.8 kg, DUP post = 472.4 ± 60.6 kg; TDUP pre = 427.1 ± 79.2 kg, TDUP post = 476.5 ± 74.1 kg), and Wilk’s score (DUP pre = 287.5 ± 49.3, DUP post = 320.0 ± 45.6; TDUP pre = 298.3 ± 45.8, TDUP post = 331.6 ± 38.7). However, no interaction effects were observed between DUP and TDUP for any of the strength dependent variables. These results suggest that 8 weeks of tiered DUP resistance training leads to similar gains in strength compared to the traditional DUP model in trained males. This could be a result of the similar workload between both groups. While not significant, traditional DUP may be more efficacious for improving back squat 1RM (DUP = 16%; TDUP = 13%), while TDUP may elicit greater strength gains in the deadlift (DUP = 9%; TDUP = 12%). Furthermore, this study demonstrates that exercise order and training intensity can be manipulated throughout each training session according to personal preference while maintaining strength adaptations within a DUP model. Lastly, dropout rates in this study lead researchers to conclude that the DUP protocols investigated should be transient and not used as a long term training approach.

Orientador: José Martins Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T16:27:12Z (GMT). No. of bitstreams: 1 Urtado_ChristianoBertoldo_D.pdf: 3494478 bytes, checksum: 64e5dc1d46649718732ff1079bb288d0 (MD5) Previous issue date: 2014 / 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

Orientador: Cláudia Regina Cavaglieri / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-27T11:34:48Z (GMT). No. of bitstreams: 1 Berton_RicardoPaesdeBarros_M.pdf: 1847286 bytes, checksum: 4830e523d7077e934302548c90bf627b (MD5) Previous issue date: 2015 / Resumo: pós a realização de uma sessão de treinamento de força, diversos metabólitos são alterados. Adicionalmente, esta resposta metabólica está envolvida em uma complexa rede metabólica que induz a alteração de uma grande quantidade de metabólitos. Desta forma, a utilização de abordagens abrangentes como a metabolômica, torna-se essencial para o entendimento do exercício de forma global. Portanto, o presente estudo teve como objetivo investigar a resposta metabólica após uma sessão de treinamento de força, por meio da metabolômica. Foram recrutados 10 indivíduos jovens do sexo masculino, que realizaram dois exercícios para membros inferiores (leg press e cadeira extensora). O protocolo constitui de quatro séries de 10 repetições, a uma intensidade de 70% de uma repetição máxima, com intervalo de 60 segundos entre as séries e entre os exercícios. As coletas sanguíneas foram realizadas nos momentos, -60 minutos, pré exercício, cinco, 15, 30 e 60 minutos após o exercício. As análises sanguíneas foram realizadas por meio da ressonância magnética nuclear. Para a análise estatística foi utilizado a análise de componentes principais e ANOVA one way para mediadas repetidas. A análise de componentes principais evidenciou uma segregação de 47.7% nos três primeiros componentes principais. Adicionalmente, foram identificados 49 metabólitos dos quais 13 metabólitos obtiveram em um e/ou mais momentos após exercício, uma alteração significante em comparação ao momento pré exercício (piruvato, lactato, succinato, 2-oxoisocaproato, alanina, 2-hidroxibutirato, 3-Hydroxi-isobutirato, hipoxantina, leucina, isoleucina, valina, lisina e ornitina). Em conclusão, é possível afirmar que a utilização da metabolômica pode ser uma ferramenta importante, uma vez que a metabolômica possibilita compreender a resposta metabólica global do exercício. Adicionalmente, possibilita a geração de novas hipóteses e descobertas / Abstract: After performing a strength training session, several metabolites are changed. Additionally, this metabolic response is involved in a complex network that induces metabolic changes in a large number of metabolites. Thus, extensive use of approaches such as metabolomics, it becomes essential to the understanding of the exercise globally. Therefore, this study aimed to investigate the metabolic response after a strength training session, through metabolomics. We recruited 10 young males, who performed two exercises for lower limbs (leg press and leg extension). The protocol was four sets of 10 repetitions, intensity of 70% of one repetition maximum, with an interval of 60 seconds between sets and between exercises. Blood samples were taken at times, -60 minutes pre exercise, five, 15, 30 and 60 minutes after exercise. Blood tests were performed using nuclear magnetic resonance. Statistical analysis was performed using principal component analysis and one-way ANOVA for repeated mediated. The principal component analysis showed a segregation of 47.7% in the first three components. Additionally, 49 metabolites were identified and 13 metabolites obtained in one and/or more times after exercise, a significant change compared to the pre exercise time (pyruvate, lactate, succinate, 2-oxoisocaproate, alanine, 2-hydroxybutyrate, 3-Hydroxy-isobutyrate, hypoxanthine, leucine, isoleucine, valine, lysine, and ornithine). In conclusion, the use of metabolomics can be an important tool, as metabolomics allows to understand the overall metabolic response to exercise. Additionally, it allows the generation of new hypotheses and discoveries / Mestrado / Atividade Fisica Adaptada / Mestre em Educação Física

Para avaliar a participação do Sistema Renina Angiotensina (SRA) sobre a Hipertrofia Cardíaca de ratos submetidos ao treinamento resistido foram usados 64 Ratos Wistar divididos em: Controle (CO), Treinado (TR), Controle ou Treinado tratados com Losartan (LOS; 20mg/Kg/d) e Controle ou Treinado tratados com NaCl (SAL; 1% água). Os grupos treinados realizaram quatro séries de 12 repetições, 5x/sem/8sem, com 65-75% de 1 Repetição Máxima (1RM). Hipertrofia cardíaca (HC), obtida pelo peso úmido do VE corrigida pelo Peso Corporal (PC) e pelo Ecocardiograma, foi observada no grupo TR com nenhum prejuízo da função ventricular. Tanto a atividade da ECA, sistêmica e local no coração, quanto a atividade da renina não foram alteradas pelo treinamento. Pelo Western blotting, não foi observada alteração na expressão protéica do peptídeo angiotensina II e do receptor de angiotensina II AT2 com o treinamento, mas observou-se aumento de 31,4% na expressão dos receptores de angiotensina II AT1 no grupo TR. A administração do antagonista do receptor AT1 (Losartan) preveniu a HC em resposta ao treinamento. O mesmo não foi observado com a administração do NaCl para inibir a atividade da Renina. Esses resultados sugerem que o receptor AT1 participa da HC induzida pelo treinamento resistido sem a necessidade de aumento na concentração da angiotensina II cardíaca. Um possível mecanismo seria a ativação direta dos receptores AT1 pelo estiramento mecânico dos cardiomiócitos. / Besides the well-known effects of Ang II in stimulating pathological pressure-overload cardiac hypertrophy, little information is available regarding the role of Renin-Angiotensin-System (RAS) in the exercise training-induced cardiac hypertrophy. 64 male Wistar rats were divided into 6 groups: Sedentary, Trained, Sedentary or Trained + Losartan (20mg/Kg/d, n=7) and Sedentary or Trained + Salt (NaCl 1%). The exercise protocol was: 4 x 12 bouts, 5x/week during eight weeks, with 65-75% of 1 Repetition Maximum (1RM). Using LV weight/body weight ratio and echocardiography (ECHO) we have observed cardiac hypertrophy in the Trained group without any impairment in ventricular function. Concerning RAS, neither ACE, analyzed by fluorometric assay (systemic and local in the heart), nor Renin, by RIA, activities were altered after resistance training. In addition, using Western blotting analysis, no change was observed in cardiac Ang II and AT2 receptor levels while the AT1 receptor expression was upregulated in Trained groups by 31,4%. Administration of the AT1 receptor antagonist (losartan) prevented left ventricle hypertrophy in response to the resistance training. The administration of salt, to inhibit the renin activity, did not prevent the cardiac hypertrophy. These results suggest that the AT1 receptor participates in resistance-training-induced cardiac hypertrophy without an increase in Ang II concentration in the heart. A possible mechanism is the direct activation of the AT1 receptor by mechanical stretching of cardiomyocytes.

De nos jours, l’entraînement en musculation occupe une part importante dans la programmation d’entraînement des sportifs car il permet d’optimiser deux paramètres essentiels à la performance, la force et la puissance. Les stratégies nutritionnelles qui accompagnent les séances de musculation sont susceptibles d’influencer les réponses à l’entraînement. Parmi ces stratégies, celle qui a surtout retenu l’attention du monde scientifique concerne les caractéristiques des apports protéiques, et notamment les aspects de quantité, de qualité et du moment d’apport optimaux. Alors que la grande majorité des travaux ont été conduit dans le cadre d’un exercice unique, ce travail de thèse se propose d’évaluer l’intérêt d’un apport protéique en récupération d’exercices programmés dans le cadre d’un entraînement en musculation de plusieurs semaines. Il s’agit de 1) préciser l’impact du rapport entre les protéines lentes (caséines) et les protéines rapides (lactosérum) du lait - présentes dans une boisson protéique de récupération - sur les adaptations musculaires à un entraînement en musculation (masse musculaire et force) et, 2) de vérifier l’intérêt et le moment optimal d’un apport en protéines lentes, à distance de l’entraînement en musculation, sur les réponses musculaires à l’entraînement. Les résultats de la première étude montrent une augmentation significative de la concentration plasmatique en leucine lorsque la proportion de protéines rapides est supérieure ou égale à la proportion de protéines lentes, par rapport à la situation inverse (plus de caséine que de lactosérum). Mais, ceci ne se traduit pas par des gains hypertrophiques supérieurs. La seconde étude, 1) confirme l’intérêt de l’ingestion de protéines rapides après chaque séance pour améliorer le gain de masse musculaire en réponse à l’entraînement en musculation, et 2) suggère l’intérêt d’un apport de caséine 3h après la fin de chaque séance d’entraînement pour maximiser les gains de force pendant l’entraînement en musculation. Ces résultats permettent de préciser les recommandations d’apport en protéines en phase de récupération de séances de musculation, tant au plan de la qualité des apports azotés (étude 1), de leur quantité (études 1 et 2), que du moment d’apport (étude 2). / Nowadays, resistance training plays an important part in the training programmes of sportsmen, because it can optimise two essential parameters of physical performance: strength and power. Nutritional strategies following exercise can maximise the muscle responses from resistance training. Quality, quantity and timing of protein intake have particularly engaged the attention of scientific studies. While the majority of relevant research has investigated the intake of protein after a single bout of resistance exercise, this particular research project aims to investigate the effect of post-exercice protein intake during several weeks of resistance training.The objectives of this project are 1) to identify the optimal ratio between slow proteins (casein) and fast proteins (whey) of milk, present in a recovery riched-protein drink, on the muscle adaptations from resistance training (muscle mass and strength) and, 2) to investigate the muscle responses to slow protein intake a few hours after resistance training exercise. Results from the first study show that there is no resulting gain in muscle mass when the ratio of fast protein is equal to or higher than that of slow protein, despite an resulting increase in plasma leucine. The second study 1) confirms that ingestion of fast protein after each resistance training session improves muscle mass and strength gains, and 2) suggests that intake of casein 3 hours after the end of each training session can maximise the gain of strength during resistance training. These results allow specific recommendations to be formulated for protein intake during the recovery period after resistance training, both in planning the quality (study 1), quantity (studies 1 and 2) and timing (study 2) of protein intake during resistance training programmes.

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