Scarpelli, MC, Nóbrega, SR, Santanielo, N, Alvarez, IF, Otoboni, GB, Ugrinowitsch, C, and Libardi, CA. Muscle hypertrophy response is affected by previous resistance training volume in trained individuals. J Strength Cond Res 36(4): 1153–1157, 2022—The purpose of this study was to compare gains in muscle mass of trained individuals after a resistance training (RT) protocol with standardized (i.e., nonindividualized) volume (N-IND), with an RT protocol using individualized volume (IND). In a within-subject approach, 16 subjects had one leg randomly assigned to N-IND (22 sets·wk−1, based on the number of weekly sets prescribed in studies) and IND (1.2 × sets·wk−1 recorded in training logs) protocols. Muscle cross-sectional area (CSA) was assessed by ultrasound imaging at baseline (Pre) and after 8 weeks (Post) of RT, and the significance level was set at p < 0.05. Changes in the vastus lateralis CSA (difference from Pre to Post) were significantly higher for the IND protocol (p = 0.042; mean difference: 1.08 cm2; confidence interval [CI]: 0.04–2.11). The inferential analysis was confirmed by the CI of the effect size (0.75; CI: 0.03–1.47). Also, the IND protocol had a higher proportion of individuals with greater muscle hypertrophy than the typical error of the measurement (chi-square, p = 0.0035; estimated difference = 0.5, CI: 0.212–0.787). In conclusion, individualizing the weekly training volume of research protocols provides greater gains in muscle CSA than prescribing a group standard RT volume.
The aim of this study was to compare the effects of resistance training to muscle failure (RT-F) and non-failure (RT-NF) on muscle mass, strength and activation of trained individuals. We also compared the effects of these protocols on muscle architecture parameters. A within-subjects design was used in which 14 participants had one leg randomly assigned to RT-F and the other to RT-NF. Each leg was trained 2 days per week for 10 weeks. Vastus lateralis (VL) muscle cross-sectional area (CSA), pennation angle (PA), fascicle length (FL) and 1-repetition maximum (1-RM) were assessed at baseline (Pre) and after 20 sessions (Post). The electromyographic signal (EMG) was assessed after the training period. RT-F and RT-NF protocols showed significant and similar increases in CSA (RT-F: 13.5% and RT-NF: 18.1%; P < 0.0001), PA (RT-F: 13.7% and RT-NF: 14.4%; P < 0.0001) and FL (RT-F: 11.8% and RT-NF: 8.6%; P < 0.0001). All protocols showed significant and similar increases in leg press (RT-F: 22.3% and RT-NF: 26.7%; P < 0.0001) and leg extension (RT-F: 33.3%, P < 0.0001 and RT-NF: 33.7%; P < 0.0001) 1-RM loads. No significant differences in EMG amplitude were detected between protocols ( P > 0.05). In conclusion, RT-F and RT-NF are similarly effective in promoting increases in muscle mass, PA, FL, strength and activation.
N óbrega, SR, Scarpelli, MC, Barcelos, C, Chaves, TS, and Libardi, CA. Muscle hypertrophy is affected by volume load progression models. J Strength Cond Res 37(1): 62-67, 2023-This exploratory secondary data analysis compared the effects of a percentage of 1 repetition maximum (%1RM) and a repetition zone (RM Zone) progression model carried out to muscle failure on volume load progression (VL Pro ), muscle strength, and cross-sectional area (CSA). The sample comprised 24 untrained men separated in 2 groups: %1RM (n 5 14) and RM Zone (n 5 10). Muscle CSA and muscle strength (1RM) were assessed before and after 24 training sessions, and an analysis of covariance was used. Volume load progression and accumulated VL (VL Accu ) were compared between groups. The relationships between VL Prog , VL Accu , 1RM, and CSA increases were also investigated. A significance level of p # 0.05 was adopted for all statistical procedures. Volume load progression was greater for RM Zone compared with %1RM (2.30 6 0.58% per session vs. 1.01 6 0.55% per session; p , 0.05). Significant relationships were found between 1RM and VL Prog (p , 0.05) and CSA and VL Prog (p , 0.05). No between-group differences were found for VL Accu (p . 0.05). Analysis of covariance revealed no between-group differences for 1RM absolute (p , 0.05) or relative changes (p , 0.05). However, post hoc testing revealed greater absolute and relative changes in CSA for the RM Zone group compared with the %1RM group (p , 0.001). In conclusion, RM Zone resulted in a greater VL Pro rate and muscle CSA gains compared with %1RM, with no differences in VL Accu and muscle strength gains between progression models.
In aging populations for which the use of high loads is contraindicated, low load resistance training associated with blood flow restriction (RT-BFR) is an alternative strategy to induce muscle mass gains. This study investigates the effects of RT-BFR on muscle mass, muscle function, and quality of life of a 99-year-old patient with knee osteoarthritis and advanced muscle mass deterioration. Training protocol consisted of 24 sessions of a unilateral free-weight knee extension exercise associated with partial blood flow restriction through a manometer cuff set at 50% of complete vascular occlusion pressure. We evaluated: cross-sectional area (CSA) and thickness (MT) of the vastus lateralis muscle by ultrasound; function through the Timed Up and Go (TUG) test; and quality of life (QoL) by the WHOQOL-bref, WHOQOL-OLD and WOMAC questionnaires. All tests were performed prior to the training period (Pre) and after the 12th (Mid) and 24th (Post) sessions. Changes were considered significant if higher than 2 times the measurement's coefficient of variation (CV). After 24 sessions, there was an increase of 12% in CSA and 8% in MT. Questionnaires scores and TUG values worsened from Pre to Mid and returned in Post. We consider RT-BFR a viable and effective strategy to promote muscle mass gains in nonagenarians and delay the decline in functionality and QoL associated with aging.
Agradeço sinceramente a todos que de alguma forma contribuíram para que eu concluísse essa trabalhosa, mas gratificante etapa da minha formação. Algumas dessas pessoas foram determinantes para a realização desse trabalho e merecem um agradecimento especial.Em primeiro lugar agradeço ao meu orientador, Sérgio Kannebley Jr., por me dedicar seu tempo e atenção com muita paciência. Agradeço pela minuciosidade e exigência que elevaram a qualidade do nosso trabalho, pelas palavras de incentivo e o bom-humor em todas as nossas reuniões.Aos professores e funcionários da FEA-RP/USP, pelo esforço e dedicação que me proporcionaram o suporte necessário para concluir esse trabalho.Aos meus colegas de mestrado pelo companheirismo dentro e fora da sala de aula, ajudando a aliviar os momentos mais difíceis e dividindo as preocupações, dúvidas e ansiedades.Agradeço especialmente àqueles que além de colegas se tornaram grandes amigos e me incentivaram e ajudaram durante todo o processo: Liliane, Juliana, Priscila, Diogo e Renato.Ao meu irmão Alexandre, por fazer com que eu me sinta admirada e me estimular a ser um bom exemplo. Obrigada pelo carinho e amizade.Acima de tudo, agradeço aos meus pais, Heloisa e Moacir, pelo apoio incondicional, confiança, amor e força nos momentos mais difíceis. Agradeço por acreditarem tanto em mim, por permitirem que eu siga meus próprios passos e por dividirem comigo todas as alegrias. Divido mais essa conquista com vocês.Por fim, agradeço à FAPESP pelo auxílio financeiro. RESUMOApesar da recente queda no crescimento das exportações, a resposta das vendas externas à valorização cambial tem sido mais lenta do que previa a teoria econômica. Essas evidências sugerem a lentidão na correção dos desvios de uma relação de longo prazo entre o câmbio e as exportações, motivando a pesquisa sobre a presença de hysteresis no comércio brasileiro. O objetivo deste estudo é confirmar as predições da teoria de hysteresis em nível macroeconômico para as exportações manufaturadas brasileiras. Para isso, propõe-se um diferencial metodológico: a inclusão, nos modelos de oferta e demanda de exportações, de variável representativa de hysteresis, construída segundo o método de Piscitelli et al. (2000), testando sua significância nas equações. São utilizados modelos com dados em painel, metodologia que permite lidar com efeitos específicos aos setores industriais e realizar testes de hysteresis para o total das exportações manufaturadas a partir de informações desagregadas, proporcionado maior eficiência na estimação. Além disso, é investigada a estacionariedade das séries de dados, realizando testes para raiz unitária e cointegração em painel. Também são estimados os parâmetros das relações de longo prazo entre as variáveis. Os resultados confirmam a hipótese de uma relação de hysteresis, em especial, nas equações de demanda por exportações brasileiras.Palavras-chave: Cointegração em painel. Exportações brasileiras. Hysteresis. Taxa real de câmbio. ABSTRACTIn spite of the recent fall of the growth rate of Brazilian expor...
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