Efeito do volume do treino de potência nas adaptações neuromusculares de mulheres idosas

O treino de potência muscular (TP) é mostrado ser uma modalidade de treinamento efetiva e segura para amenizar os prejuízos neuromusculares causados pelo envelhecimento. Porém, ainda há necessidade de mais informação a respeito da prescrição do TP. Assim, o objetivo do presente estudo foi comparar o efeito de 12 e 24 semanas de dois modelos de TP sobre as adaptações neuromusculares de mulheres idosas. Trinta mulheres idosas (60-68 anos) foram randomicamente alocadas em um dois dois grupos: grupo com variação do número séries (VS; n = 15) ou grupo com número de séries constantes (SC; n = 15). Durante o programa de TP o grupo VS realizou uma série por exercício durante as 12 primeiras semanas e a partir da décima terceira semana realizou três séries, enquanto que o grupo SC realizou três séries por exercício durante todo o período de treinamento. Uma repetição máxima (1-RM), contração isométrica voluntária máxima (CIVM), espessura muscular do quadríceps (EMQUA), taxa de produção de torque absoluta e normalizada (TPT, TPTN, respectivamente), impulso contrátil, potência muscular no salto com contra movimento e o desempenho funcional foram avaliados pré (Pré), após 12 (Pós 12) e após 24 (Pós 24) semanas de TP. Os grupos, VS e SC, aumentaram significativa (p ≤ 0,001 – 0,0001) e similarmente (p > 0,05) o 1-RM de extensão de joelhos, a CIVM e a EMQUA Pós 12 e Pós 24 semanas de treinamento. Além disso, quando analisado o aumento do Pós 12 ao Pós 24 semanas, ambos os grupos também mostraram aumento significativo nessas variáveis (p ≤ 0,05), sem diferença entre eles (p > 0,05). A TPT e o impulso contrátil apresentaram melhora significativa Pós 12 e Pós 24 semanas de treinamento (p ≤ 0,01 – 0,0001), enquanto que a TPTN apresentou aumento significativo apenas no Pós 24 (p ≤ 0,05). Ainda, a TPT e impulso contrátil apresentaram melhora significativa (p ≤ 0,05) do Pós 12 ao Pós 24, de maneira similar para ambos os grupos (p > 0,05). A potência muscular e o desempenho também melhoraram significativa (p ≤ 0,01 – 0,0001) e similarmente (p > 0,05) para ambos os grupos Pós 12 e Pós 24 semanas de treinamento. Em resumo o presente estudo encontrou que os grupos VS e CS melhoraram significativa e similarmente as variáveis neuromusuclares e o desempenho funcional Pós 12 e Pós 24 semanas de treinamento. Além disso, o grupo VS comparado ao grupo CS, não teve atenuação nos ganhos Pós 24 semanas de TP em nehuma das variváeis neuromusculares avaliadas e no desempenho funcional.The power training (PT) has been shown to be an effective and safe training mode to attenuate the deleterious effects of aging in neuromuscular variables. However, still there is the need for information regarding to PT prescription. Thus, the aim of present study was to compare the effect of 12 and 24 weeks of PT on neuromuscular adaptations in elderly women. Thirty elderly women (60- 68 years) were randomly assigned to one of two groups: group with variation in number of sets (VS; n = 15) or group with number of constant sets (CS; n= 15). During PT routine the VS group perfomed one set by exercise during the first 12 weeks and from the thirteenth week they performed three sets by exercise, whereas CS group performed three sets during entire training period. Onerepetition maximum (1-RM) and maximum isometric voluntary contraction (MIVC) of knee extension, quadriceps femoris muscle thickness (QF MT), absolute and normalized rate of torque development (RTD and RTDN, respectively), contractile impulse, muscle power in countermovement jump and functional performance were assessed before training (Pre), after 12 (Post 12) and after 24 (Post 24) weeks of training. The groups, VS and CS, increased significant (p ≤ 0.001 – 0.0001) and similarly (p > 0.05) the 1-RM, MIVC and QF MT at Post 12 and Post 24 weeks of training. Furthermore, when analyzed the increase of Post 12 to Post 24 weeks, both groups showed significant increases in these variables (p ≤ 0.05), with no difference between groups (p > 0.05). The RTD and the contractile impulse showed significant improvements at Post 12 and Post 24 weeks of training (p ≤ 0.01 – 0.0001), while that the RTDN increased only at Post 24 (p ≤ 0.05). Moreover, RTD and contractile impulse significantly increased from Post 12 to Post 24 weeks, similarly for both groups (p > 0.05). The muscle power and the functional performance also showed significant (p ≤ 0.01 – 0.0001) and similar (p > 0.05) improvements in both groups at Post 12 and Post 24 weeks of training. In summary, the study found that the groups VS and SC improved significant and similarly the neuromuscular variables and functional performance at Post 12 and Post 24 weeks of PT. Furthermore, the VS group compared to SC group did not showed attenuated gains at Post 24 weeks of PT in any neuromuscular variable assessed and in functional performance

Exercise effects on muscle quality in older adults: A systematic review and meta-analysis

To systematically review and analyse the effects of exercise on morphological and neuromuscular muscle quality (MQ) outcomes in older adults and assess a range of possible moderators that may affect the impact of exercise on MQ outcomes. Using PRISMA guidelines, randomised controlled trials were searched in CINAHL, EMBASE, LILACS, PubMed, SciELO, Web of Science, MedNar, OpenGrey and OpenThesis databases. Eligible trials examined the effects of exercise interventions on morphological and neuromuscular MQ in older adults ( ≥ 60 years). Twenty-one trials (n = 973 participants) were included. Exercise significantly improved morphological MQ (effect size (ES) = 0.32, 95% CI 0.13–0.51, P \u3c 0.001) with significant results maintained for studies assessing muscle density and intermuscular adipose tissue (ES = 0.45–0.52, P \u3c 0.05). For neuromuscular MQ, exercise provided significant positive effects (ES = 0.49, 95% CI 0.29–0.69, P \u3c 0.001) but only maintained for physically healthy participants (ES = 0.43, P \u3c 0.001), resistance exercise interventions (ES = 0.64, P \u3c 0.001), or studies assessing 1-RM or knee extensor isokinetic muscle strength relative to leg lean mass (ES = 0.48–0.62, P = 0.001). Associations between exercise duration and changes in MQ measures were not observed (P \u3e 0.05). Supervised exercise interventions significantly improved different measures of MQ regardless of exercise duration, although these effects were small-to-moderate and not supported across all population-, exercise-, and methods-related features

Does high-velocity resistance exercise elicit greater physical function benefits than traditional resistance exercise in older adults? A systematic review and network meta-analysis of 79 trials

Background A systematic review and network meta-analysis was undertaken to examine the effectiveness of different modes of resistance exercise velocity in fast walking speed, timed-up and go, 5-times sit-to-stand, 30-second sit-to-stand, and 6-minute walking tests in older adults. Methods CINAHL, Embase, LILACS, PubMed, Scielo, SPORTDiscus, and Web of Science databases were searched up to February 2022. Eligible randomized trials examined the effects of supervised high-velocity or traditional resistance exercise in older adults (ie, ≥ 60 years). The primary outcome for this review was physical function measured by fast walking speed, timed-up and go, 5-times sit-to-stand, 30-second sit-to-stand, and 6-minute walking tests, while maximal muscle power and muscle strength were secondary. A random-effects network meta-analysis was undertaken to examine the effects of different resistance exercise interventions. Results Eighty articles describing 79 trials (n = 3 575) were included. High-velocity resistance exercise was the most effective for improving fast walking speed (standardized mean difference [SMD] −0.44, 95% confidence interval [CI]: 0.00 to 0.87), timed-up and go (SMD −0.76, 95% CI: −1.05 to −0.47), and 5-times sit-to-stand (SMD −0.74, 95% CI: −1.20 to −0.27), while traditional resistance exercise was the most effective for 30-second sit-to-stand (SMD 1.01, 95% CI: 0.68 to 1.34) and 6-minute walking (SMD 0.68, 95% CI: 0.34 to 1.03). Conclusion Our study provides evidence that resistance exercise velocity effects are specific in older adults, as evidenced by physical function test dependence. We suggest that prescriptions based on the velocity of contraction should be individualized to address the specific functional needs of participants

Comparison of muscle quality and functional capacity between Japanese and Brazilian older individuals

Muscle quality is well-known to decrease with aging and is a risk factor for metabolic abnormalities. However, there is a lack of information on race-associated differences in muscle quality and other neuromuscular features related to functional performance. This study aimed to compare muscle quality, function, and morphological characteristics in Japanese and Brazilian older individuals. Eighty-four participants aged 65–87 years were enrolled in the study (42 Japanese: 23 men, 19 women, mean age 70.4 years; 42 Brazilians: 23 men, 19 women, mean age 70.8 years). Echo intensity (EI) and muscle thickness (MT) of the quadriceps femoris were measured using B-mode ultrasonography. A stepwise multiple linear regression analysis with EI as a dependent variable revealed that MT was a significant variable for Japanese participants (R2 = 0.424, P = 0.001), while MT and subcutaneous adipose tissue (SCAT) thickness were significant variables for Brazilian participants (R2 = 0.490, P = 0.001). A second stepwise multiple linear regression analysis was performed after excluding MT and SCAT thickness from the independent variables. Sex and age for Japanese participants (R2 = 0.381, P = 0.001) and lean body mass and body mass index for Brazilian participants (R2 = 0.385, P = 0.001) were identified as significant independent variables. The present results suggest that MT is closely correlated with muscle quality in Japanese and Brazilian older individuals. Increases in muscle size may induce decreases in intramuscular adipose tissue and/or connective tissues, which are beneficial for reducing the risks of metabolic impairments in Japanese and Brazilian older individuals

Efeito do volume do treino de potência nas adaptações neuromusculares de mulheres idosas

O treino de potência muscular (TP) é mostrado ser uma modalidade de treinamento efetiva e segura para amenizar os prejuízos neuromusculares causados pelo envelhecimento. Porém, ainda há necessidade de mais informação a respeito da prescrição do TP. Assim, o objetivo do presente estudo foi comparar o efeito de 12 e 24 semanas de dois modelos de TP sobre as adaptações neuromusculares de mulheres idosas. Trinta mulheres idosas (60-68 anos) foram randomicamente alocadas em um dois dois grupos: grupo com variação do número séries (VS; n = 15) ou grupo com número de séries constantes (SC; n = 15). Durante o programa de TP o grupo VS realizou uma série por exercício durante as 12 primeiras semanas e a partir da décima terceira semana realizou três séries, enquanto que o grupo SC realizou três séries por exercício durante todo o período de treinamento. Uma repetição máxima (1-RM), contração isométrica voluntária máxima (CIVM), espessura muscular do quadríceps (EMQUA), taxa de produção de torque absoluta e normalizada (TPT, TPTN, respectivamente), impulso contrátil, potência muscular no salto com contra movimento e o desempenho funcional foram avaliados pré (Pré), após 12 (Pós 12) e após 24 (Pós 24) semanas de TP. Os grupos, VS e SC, aumentaram significativa (p ≤ 0,001 – 0,0001) e similarmente (p > 0,05) o 1-RM de extensão de joelhos, a CIVM e a EMQUA Pós 12 e Pós 24 semanas de treinamento. Além disso, quando analisado o aumento do Pós 12 ao Pós 24 semanas, ambos os grupos também mostraram aumento significativo nessas variáveis (p ≤ 0,05), sem diferença entre eles (p > 0,05). A TPT e o impulso contrátil apresentaram melhora significativa Pós 12 e Pós 24 semanas de treinamento (p ≤ 0,01 – 0,0001), enquanto que a TPTN apresentou aumento significativo apenas no Pós 24 (p ≤ 0,05). Ainda, a TPT e impulso contrátil apresentaram melhora significativa (p ≤ 0,05) do Pós 12 ao Pós 24, de maneira similar para ambos os grupos (p > 0,05). A potência muscular e o desempenho também melhoraram significativa (p ≤ 0,01 – 0,0001) e similarmente (p > 0,05) para ambos os grupos Pós 12 e Pós 24 semanas de treinamento. Em resumo o presente estudo encontrou que os grupos VS e CS melhoraram significativa e similarmente as variáveis neuromusuclares e o desempenho funcional Pós 12 e Pós 24 semanas de treinamento. Além disso, o grupo VS comparado ao grupo CS, não teve atenuação nos ganhos Pós 24 semanas de TP em nehuma das variváeis neuromusculares avaliadas e no desempenho funcional.The power training (PT) has been shown to be an effective and safe training mode to attenuate the deleterious effects of aging in neuromuscular variables. However, still there is the need for information regarding to PT prescription. Thus, the aim of present study was to compare the effect of 12 and 24 weeks of PT on neuromuscular adaptations in elderly women. Thirty elderly women (60- 68 years) were randomly assigned to one of two groups: group with variation in number of sets (VS; n = 15) or group with number of constant sets (CS; n= 15). During PT routine the VS group perfomed one set by exercise during the first 12 weeks and from the thirteenth week they performed three sets by exercise, whereas CS group performed three sets during entire training period. Onerepetition maximum (1-RM) and maximum isometric voluntary contraction (MIVC) of knee extension, quadriceps femoris muscle thickness (QF MT), absolute and normalized rate of torque development (RTD and RTDN, respectively), contractile impulse, muscle power in countermovement jump and functional performance were assessed before training (Pre), after 12 (Post 12) and after 24 (Post 24) weeks of training. The groups, VS and CS, increased significant (p ≤ 0.001 – 0.0001) and similarly (p > 0.05) the 1-RM, MIVC and QF MT at Post 12 and Post 24 weeks of training. Furthermore, when analyzed the increase of Post 12 to Post 24 weeks, both groups showed significant increases in these variables (p ≤ 0.05), with no difference between groups (p > 0.05). The RTD and the contractile impulse showed significant improvements at Post 12 and Post 24 weeks of training (p ≤ 0.01 – 0.0001), while that the RTDN increased only at Post 24 (p ≤ 0.05). Moreover, RTD and contractile impulse significantly increased from Post 12 to Post 24 weeks, similarly for both groups (p > 0.05). The muscle power and the functional performance also showed significant (p ≤ 0.01 – 0.0001) and similar (p > 0.05) improvements in both groups at Post 12 and Post 24 weeks of training. In summary, the study found that the groups VS and SC improved significant and similarly the neuromuscular variables and functional performance at Post 12 and Post 24 weeks of PT. Furthermore, the VS group compared to SC group did not showed attenuated gains at Post 24 weeks of PT in any neuromuscular variable assessed and in functional performance

Efeito de dois volumes de treinamento de força nas adaptações neuromusculares de mulheres idosas

O processo de envelhecimento causa importantes prejuízos na função neuromuscular. O treinamento de força já demonstrou ser um eficiente método de exercício para amenizar em certo grau os efeitos do processo de envelhecimento. Porém, para isso algumas variáveis, como o volume de treinamento, precisam ser controladas. Assim, o objetivo desse estudo foi verificar o efeito de dois volumes de treinamento de força, série simples e séries múltiplas, nas adaptações neuromusculares dos membros inferiores e superiores de mulheres idosas. No primeiro estudo experimental, 27 sujeitos foram divididos em dois grupos de treinamento: grupo série simples (SS; n=14) e grupo séries múltiplas (SM; n=13). O grupo SS realizou uma série em exercício, enquanto que o grupo SM realizou três séries em cada exercício. O valor de uma-repetição máxima (1-RM) de extensão de joelho e flexão de cotovelo, a espessura muscular (EM) dos músculos extensores de joelho e flexores de cotovelo, bem como a força isométrica máxima e a ativação eletromiográfica (EMG) máxima dos membros inferiores e superiores foram avaliadas pré e após seis semanas de treinamento. Os resultados demonstraram que ambos os grupos incrementaram significativamente o 1-RM de extensão de joelho e flexão de cotovelo e a EM dos músculos extensores de joelho e flexores de cotovelo, sem diferença entre eles. No estudo experimental dois, 20 mulheres idosas foram divididas em dois grupos de treinamento: grupo SS (n=11) e grupo SM (n=9). O 1-RM de extensão de joelho e flexão de cotovelo, a EM dos músculos extensores de joelho e flexores de cotovelo, força isométrica máxima e ativação EMG máxima dos membros inferiores e superiores, bem como a qualidade muscular avaliada por echo intensity obtida por ultrassonografia (QMEI), por tensão específica (QMTE), e por tensão específica ajustando os valores de massa muscular por uma escala alométrica (QMEA). Após 13 semanas de treinamento, ambos os grupos incrementaram significativamente o 1-RM de extensão de joelho e a flexão de cotovelo, a EM dos membros inferiores e superiores e a EMG máxima dos músculos vasto medial e bíceps braquial, bem como a QMEI, QMTE, QMEA, sem diferença entre os grupos em nenhuma variável. No estudo experimental três, 20 sujeitos foram divididos em dois grupos de treinamento, grupo SS (n=11) e SM (n=9). O 1-RM de extensão de joelho e flexão de cotovelo, a EM dos músculos extensores de joelho e flexores de cotovelo, força isométrica máxima e ativação EMG máxima dos membros inferiores e superiores, bem como a QMEI foram avaliadas após 6, 13 e 20 semanas de treinamento. Ambos os grupos incrementaram significativamente o 1-RM de extensão de joelho e flexão de cotovelo após 6, 13 e 20 semanas de treinamento, sendo que após 20 semanas o grupo SM apresentou um ganho significativamente maior. A força isométrica máxima dos membros inferiores apenas aumentou após 20 semanas de treinamento e a força isométrica máxima dos membros superiores aumentou após 13 e 20 semanas de treinamento. A EM dos membros inferiores e superiores aumentou em todos os momentos, de modo que após 20 semanas o grupo SM apresentou um ganho significativamente maior com relação a EM dos membros inferiores. Ambos os grupos apresentaram ganho significativo na EMG máxima dos membros inferiores e superiores apenas após 20 semanas de treinamento. A QMEI aumentou significativamente após 13 e 20 semanas de treinamento em ambos os grupos, de modo que o grupo SM apresentou um ganho significativamente maior. O resultado desse estudo demonstraram que mulheres idosas podem obter ganhos significativos com um pequeno e um grande volume de treinamento nos membros superiores, já os membros inferiores necessitam de um grande volume para obter ganhos durante longos períodos de treinamento.The aging process results in important impairments in neuromuscular function. The strength training has been shown to be a safe and an efficient method for attenuate some effects of the aging process. However, the effectiveness of strength training is dependent of the control of acute variables such as the training volume. Therefore, the aim of present study was assess the effects of the two strength training volumes, single set and multiple sets, on neuromuscular adaptations of lower- and upper-body muscles in older women. In the first experimental study, 27 subjects were divided into two training groups: single set group (SS; n=14) and multiple sets group (SM; n=13). The SS group performed one set per exercise, while the SM group performed three sets per exercise. Knee extension and elbow flexion one-repetition maximal (1- RM), muscle thickness (MT) of the knee extensors and of the elbow flexors, as well maximal electromyography (EMG) activation of the lower- and upper-body muscles were evaluated before and after six weeks of training. The results showed that both groups significantly increased the knee extension and elbow flexion 1-RM and the knee extensors and elbow flexors MT, with no difference between groups. In the second experimental study, 20 subjects were divided into two training groups: SS group (n=11) and SM group (n=9). The knee extension and elbow flexion 1-RM, MT of the knee extensors and of the elbow flexors, maximal isometric strength and maximal EMG activation of the lowerand upper-body muscles, as well as muscle quality (MQ) of the lower-body muscles measured by echo intensity obtained by ultrasonography (MQEI), strength per unit of muscle mass (MQST), and strength per unit of muscle mass adjusted with an allometric scale (MQAS) were obtained. After 13 weeks of training, both groups significantly increased knee extension and elbow flexion 1- RM, MT of the knee extensors and elbow flexors, maximal EMG activation, as well QMEI, QMTE, QMEA, with no differences between groups. In the third experimental study, 20 subjects were divided in the two training groups, SS groups (n=11) and SM group (n=9). The knee extension and elbow flexion 1- RM, knee extensors and elbow flexors MT, maximal isometric strength and maximal EMG activation of the lower- and upper-body muscles and MQEI was measured after 6, 13 and 20 weeks of training. Both groups significantly increased knee extension and elbow flexion at after 6, 13 and 20 weeks of training, however after 20 weeks knee extension 1-RM gains were greater for SM group. The maximal isometric strength of the lower-body significantly increased only after 20 weeks and the maximal isometric strength of the upperbody increased after 13 and 20 weeks of training, with no difference between groups. Both groups showed significant increases in MT of the knee extensors and elbow flexors muscles after 6, 13 and 20 weeks of training, with greater gains for the SM group after 20 weeks in knee extensors MT. The MQEI significantly increased after 13 and 20 weeks of training in both groups, with a gain significantly higher in the SM group. The findings of this study showed that older women may obtain significant gains in upper-body muscles with a lower strength training volume during long period of the training. For lower-body muscles a lower and high volume strength training were similarly effective during the early period and until three months of training; nevertheless the highvolume resulted in gains substantially higher after long period of training