Resistance training intervention performed with different muscle action durations influences the maximal dynamic strength without promoting joint-angle specific strength gains.

The present study investigated the effect of 10-week matched (range of motion, volume, intensity, rest, and repetition duration) training protocols with varying muscle action duration (MAD) on maximal voluntary isometric contraction (MVIC) test at eight different knee angles and one-repetition maximum (1RM) test after in seated knee extensor machine. Forty women were allocated into one control and three training groups with varying MAD: 5C1E (5s concentric action [CON] and 1s eccentric action [ECC]), 3C3E (3s CON and 3s ECC), and 1C5E (1s CON and 5s ECC). All training groups (5C1E, 3C3E, and 1C5E) showed a greater relative response in 1RM performance than the control group (0.1 ± 3.5%, p ≤ 0.05). The 1C5E group presented greater relative increases in the 1RM performance (22.1 ± 11.6%) compared to 5C1E (13.6 ± 9.2%; p ≤ 0.05) and 3C3E (14.1 ± 5.5%, p ≤ 0.05) groups. The training groups increased the MVIC performance more than the control group (p ≤ 0.05), although there were no significant differences between the training groups. This study demonstrated that isoinertial resistance training protocols with shorter CON MAD showed greater maximum dynamic strength performance response than matched training protocols with other MAD configurations. However, the configuration of MAD did not induce angle-specificity to increase the maximum isometric strength.

Similar Inflammatory Adaptation in Women following 10 Weeks of Two Equalized Resistance Training with Different Muscle Action Duration.

This study is aimed at evaluating the profile of inflammatory markers and components of redox regulation in untrained women after 10 weeks of resistance training using equalized protocols but different muscle action duration (MAD). Twenty-two women underwent progressive resistance training exercising the knee extensor muscles for 10 weeks-3x/week, with 3-5 sets of 6 repetitions at 50% of the 1 repetition maximum strength test (1RM), with a rest of 180 s between the series, following the training protocol (i) 5 s of concentric muscle action for 1 s of eccentric muscle action (5C-1E) and (ii) 1 s of concentric muscle action for 5 s of eccentric muscle action (1C-5E). Quadriceps muscle hypertrophy maximum strength (1RM) and redox regulation/muscle damage/inflammatory markers (CAT, SOD, TBARS, FRAP, CH, LDH, CXCL8, and CCL2) were evaluated. Plasma markers were evaluated before and 30 minutes after the first and last training sessions. A similar gain in hypertrophy and maximum strength was observed in both groups. However, in the 5C-1E, a significant major effect was observed for SOD (F 1.19 = 10.480, p = 0.004) and a significant major time effect, with a reduction in the last training session, was observed for CXCL8 (F 1.37 = 27.440, p < 0.001). In conclusion, similar protocols of resistance training, with different MAD, produced similar inflammatory and adaptive responses to strength training. As the training load is progressive, the maintenance of this inflammatory and redox regulation profile suggests an adaptive response to the proposed strength training.

Resistance training with different repetition duration to failure: effect on hypertrophy, strength and muscle activation.

BACKGROUND: This study investigated the effects of two 14-week resistance training protocols with different repetition duration (RD) performed to muscle failure (MF) on gains in strength and muscle hypertrophy as well as on normalized electromyographic (EMG) amplitude and force-angle relationships. METHODS: The left and right legs of ten untrained males were assigned to either one of the two protocols (2-s or 6-s RD) incorporating unilateral knee extension exercise. Both protocols were performed with 3-4 sets, 50-60% of the one-repetition maximum (1RM), and 3 min rest. Rectus femoris and vastus lateralis cross-sectional areas (CSA), maximal voluntary isometric contraction (MVIC) at 30o and 90o of knee flexion and 1RM performance were assessed before and after the training period. In addition, normalized EMG amplitude-angle and force-angle relationships were assessed in the 6th and 39th experimental sessions. RESULTS: The 6-s RD protocol induced larger gains in MVIC at 30o of knee angle measurement than the 2-s RD protocol. Increases in MVIC at 90o of knee angle, 1RM, rectus femoris and vastus lateralis CSA were not significant between the 2-s and 6-s RD protocols. Moreover, different normalized EMG amplitude-angle and force-angle values were detected between protocols over most of the angles analyzed. CONCLUSION: Performing longer RD could be a more appropriate strategy to provide greater gains in isometric maximal muscle strength at shortened knee positions. However, similar maximum dynamic strength and muscle hypertrophy gains would be provided by protocols with different RD.

The Effects of Altering the Concentric/Eccentric Phase Times on EMG Response, Lactate Accumulation and Work Completed When Training to Failure.

This study compared the electromyographic response, the blood lactate concentration (BLC), and the maximum number of repetitions (MNR) between protocols of different concentric/eccentric duration taken to muscle failure. This comparison may help to understand how different concentric/eccentric duration may influence performance and the central and metabolic responses in trained men. Seventeen strength-trained men performed two protocols in a counterbalanced design. Three sets of the Smith bench press exercise were performed to failure at 60% of the one-repetition maximum (1RM) using each protocol (4-s concentric/2-s eccentric [4 s: 2 s]; and 2-s concentric/4-s eccentric [2 s: 4 s]). The normalized root mean square (EMGRMS) and the mean frequency (EMGMF) of the electromyographic signals for the pectoralis major and the triceps brachii were compared in the first, middle, and last repetitions. The BLC was assessed at rest, during and after the test sessions. To compare the EMG and BLC, a 3-way ANOVA with repeated measures with a post hoc Tukey's test was used. To compare the MNR performed across the sets, an ANOVA-type rank test with the Dunn's post hoc test was used. The ANOVA indicated a greater EMGRMS for Protocol 4 s: 2 s in the pectoralis major and a lower EMGMF for Protocol 4 s: 2 s in the triceps brachii at the middle and last repetitions. Both protocols increased the EMGRMS and decreased the EMGMF across repetitions. Despite the results show different levels of activation and neuromuscular fatigue between protocols, the BLC and the MNR were similar.

Repetitions to failure increase pectoralis major activation with similar neuromuscular fatigue in trained men / Repetições até a falha aumentam a ativação do peitoral maior com similar fadiga neuromuscular em homens treinados

ABSTRACT Resistance training protocols performed to muscle failure (MF) have been employed in an attempt to maximize activation and neuromuscular fatigue. Therefore, the aim of this study was to compare the surface electromyography amplitude (EMGRMS) and frequency (EMGFREQ) of the pectoralis major between protocols performed to MF and non muscle failure (NMF). Seven trained men performed three sets at 60% of a repetition maximum, with a 3 min rest period and a 6s repetition duration. MF protocol was performing with maximum number of repetitions in all sets, while in NMF protocol subjects performed 6 repetitions in 3 sets. For data analysis two two-way repeated measures ANOVAs (Protocol x Repetition) were used and when necessary, Bonferroni post hoc was performed. The EMGRMS was higher in the protocol MF compare to NMF, but there was no difference in EMGFREQ between protocols. Although there were no significant differences in the frequency domain between protocols, perform repetitions to MF was a determining factor to generate higher amplitude of the electromyography signal. Thus, perform repetitions to MF could be considered an effective strategy to increase muscle activation in trained individuals, however, with similar neuromuscular fatigue.

RESUMO Protocolos de treinamento realizados até a falha muscular (FM) têm sido realizados na tentativa de maximizar a ativação e a fadiga neuromuscular. Portanto, o objetivo deste estudo foi comparar a amplitude do sinal eletromiografico (EMGRMS) e a frequência (EMGFREQ) do peitoral maior entre os protocolos realizados até a FM e sem falha muscular (SFM). Sete homens treinados realizaram três séries com 60% de uma repetição máxima, com um período de descanso de 3 min e uma duração da repetição de 6s. O protocolo FM foi realizado com o número máximo de repetições em todas as séries, enquanto no protocolo SFM os indivíduos realizaram 6 repetições em 3 séries. Para análise dos dados, foram utilizadas duas ANOVAs two-way com medidas repetidas (Protocolo x Repetição) e, quando necessário, foi realizado o post hoc de Bonferroni. Como resultado, a EMGRMS foi maior no protocolo FM comparado ao SFM, mas não houve diferença na EMGFREQ entre os protocolos. Embora não houvesse diferenças significativas no domínio da frequência entre os protocolos, a realização de repetições até a FM foi um fator determinante para gerar maior amplitude do sinal eletromiográfico. Assim, a realização de repetições até a FM pode ser considerada uma estratégia eficaz para aumentar a ativação muscular em indivíduos treinados, porém com fadiga neuromuscular semelhante.

A realização do sistema supersérie com diferentes segmentos corporais não impacta no volume e percepção subjetiva de esforço / The superset system performed using different limbs does not impact on volume and rating of perceived exertion / El sistema supersérie realizado con diferentes segmentos corporais no impacta en el volumen y percepción subjetiva del esfuerzo

O objetivo do estudo foi comparar os sistemas tradicional (TRAD) e supersérie (SS) quanto ao número de repetições (volume) e percepção subjetiva de esforço (PSE) nos exercícios supino e extensão de joelhos. Doze homens treinados realizaram de forma randomizada (medidas repetidas) os protocolos em sistemas TRAD e SS (4 séries com pausas de 2 minutos, intensidade de 10 repetições máximas). No sistema SS, cada série do exercício banco extensor foi realizada durante a pausa do exercício supino. Não houve diferença significativa no volume (TRAD supino - série 1: 16,1 ± 1,6; série 2: 10,9 ± 2,1; série 3: 7,8 ± 2,3; série 4: 7,0 ± 2,0; TRAD extensão de joelhos ­ série 1: 13,1 ± 2,5; série 2: 11,0 ± 2,0; série 3: 9,1 ± 1,7; série 4: 7,6 ± 1,6; SS supino ­ série 1: 16,3 ± 2,3; série 2: 10,9 ± 1,6; série 3: 7,8 ± 1,9; série 4: 6,1 ± 1,4; SS extensão de joelhos ­ série 1: 13,8 ± 1,8; série 2: 11,2 ± 1,6; série 3: 8,8 ± 1,7; série 4: 7,0 ± 1,7) e na PSE (TRAD supino - mediana série 1: 15,0; mediana série 4: 19,5; TRAD extensão de joelhos - mediana série 1: 17,0; mediana série 4: 19,5; SS supino - mediana série 1: 16,5; mediana série 4: 20,0; SS extensão de joelhos - mediana série 1: 17,5; mediana série 4: 19,5) entre os protocolos. Verificou-se redução do volume e aumento da PSE no decorrer das séries em ambas situações experimentais. Considerando a similaridade dos resultados obtidos entre os sistemas SS e TRAD, a aplicação de SS torna-se uma alternativa eficiente para a redução do tempo de treinamento.

The objective of the study was to compare the number of repetitions (volume) and the rating of perceived exertion (RPE) in the bench press and knee extension exercises when performing Traditional (TRAD) and Superset (SS) training systems. Twelve trained men randomly performed (repeated measurements) the TRAD and SS systems (4 sets and 2-minute rest intervals, intensity of 10 max repetitions). In the SS system, each set of the knee extension was performed during the interval of the bench press. There was no significant difference in volume (TRAD bench press ­ set 1: 16,1 ± 1,6; set 2: 10,9 ± 2,1; set 3: 7,8 ± 2,3; set 4: 7,0 ± 2,0; TRAD knee extension ­ set 1: 13,1 ± 2,5; set 2: 11,0 ± 2,0; set 3: 9,1 ± 1,7; set 4: 7,6 ± 1,6; SS bench press ­ set 1: 16,3 ± 2,3; set 2: 10,9 ± 1,6; set 3: 7,8 ± 1,9; set 4: 6,1 ± 1,4; SS knee extension ­ set 1: 13,8 ± 1,8; set 2: 11,2 ± 1,6; set 3: 8,8 ± 1,7; set 4: 7,0 ± 1,7) and PSE (TRAD bench press median set 1: 15,0; median set 2: 19,5; TRAD knee extension ­ median set 1: 17,0; median set 4: 19,5; SS bench press ­ median set 1:16,5; median set 4: 20,0; SS knee extension ­ median set 1: 17,5; median set 4: 19,5) between the protocols. There was a reduction in volume and increase of PSE during the sets in both experimental situations. Considering the similarity of the results obtained between the SS and TRAD systems, SS application becomes an efficient alternative for decreasing training time.

El objetivo del estudio fue comparar los sistemas Tradicional (TRAD) y Supersérie (SS) en cuanto al número de repeticiones (volumen) y percepción subjetiva de esfuerzo (PSE) en los ejercicios press de banca (PB) y extensión de rodillas (ER). Doce hombres entrenados realizaron de forma aleatorizada (mediciones repetidas) los sistemas TRAD y SS (4 series; pausas de 2 minutos, intensidad de 10 repeticiones máximas). En el sistema SS, cada serie de ER se realizó durante la pausa de PB. No hubo diferencia en el volumen (TRAD press de banca - serie 1: 16,1 ± 1,6; serie 2: 10,9 ± 2,1; serie 3: 7,8 ± 2,3; serie 4: 7,0 ± 2,0; TRAD extensión de rodillas ­ serie 1: 13,1 ± 2,5; serie 2: 11,0 ± 2,0; serie 3: 9,1 ± 1,7; serie 4: 7,6 ± 1,6; SS press de banca ­ serie 1: 16,3 ± 2,3; serie 2: 10,9 ± 1,6; serie 3: 7,8 ± 1,9; serie 4: 6,1 ± 1,4; SS extensión de rodillas ­ serie 1: 13,8 ± 1,8; serie 2: 11,2 ± 1,6; serie 3: 8,8 ± 1,7; serie 4: 7,0 ± 1,7) e na PSE (TRAD press de banca - mediana serie 1: 15,0; mediana serie 4: 19,5; TRAD extensión de rodillas - mediana serie 1: 17,0; mediana serie 4: 19,5; SS press de banca - mediana serie 1: 16,5; mediana serie 4: 20,0; SS extensión de rodillas - mediana serie 1: 17,5; mediana serie 4: 19,5) entre los protocolos. Se verificó reducción del volumen y aumento de la PSE en el curso de las series en ambas situaciones. Considerando la similitud de los resultados obtenidos entre los sistemas SS y TRAD, la aplicación de SS se convierte en una alternativa eficiente para la reducción del tiempo de entrenamiento.

The effect of 10 weeks of strength training on the electromyographic response of quadriceps portions / Efeito de 10 semanas de treinamento na resposta eletromiográfica das porções do quadríceps

Abstract This study investigate the effect of 10-week strenght training on the amplitude of the electromyographic (EMG) signal of vastus medialis, vastus lateralis and rectus Femoris. Twenty three untrained volunteers performed 3-5 sets (3 sets - weeks 1 and 2; 4 series - weeks 3 and 4; 5 series weeks 5 to 10) with 6 repetitions, intensity of 50% of 1 repetition maximum (1RM), 3 min rest between sets and 6 s repetition duration at the knee extensor exercise. One group (5:1) performed concentric action of 5 s and eccentric of 1 s and the other (3:3) performed concentric of 3 s and eccentric of 3 s. The VM, VL and RF EMG (RMS) activities were recorded in each repetition of the three series at the first training session and the first three series at the last session. The protocol 5:1 led to EMG reduction in all portions, with a greater number of repetitions presenting differences at the VL and RF. VM and RF presented similar results at Group 3:3. It was verified that all the differences occurred in the second half of the series. It was also verified differences in EMG ratios just in group 3:3 and only in VM/VL and VM/RF. These results suggest that the coordination was not affected when equivalent repetitions of series were compared. It was also suggested that these results were influenced by the reduced degrees of freedom of the exercise and the training load progression adopted.

Resumo Este estudo investigou o efeito de 10 semanas de treinamento de força na resposta eletromiográfica (EMG) do vasto medial, vasto lateral e reto femoral. 23 voluntárias executaram 3 a 5 séries de 6 repetições, intensidade de 50% de 1 repetição máxima (RM), 3 minutos de pausa entre as séries e duração da repetição de 6 s no exercício extensor de joelhos. Um grupo (5:1) realizou a duração da ação concêntrica em 5 s e excêntrica em 1s e outro grupo (3:3) realizou a concêntrica em 3s e a excêntrica em 3s. A atividades EMG (RMS) destas três porções do quadríceps foram registradas em cada repetição das 3 séries da primeira sessão de treinamento e nas três primeiras séries da última sessão. Os resultados mostraram diferenças na metade final das séries, sendo que no grupo 5:1 houve redução na EMG em todas as porções e o VL e o RF mostraram redução em um número maior de repetições. No grupo 3:3 o VM e o RF apresentaram redução. Para as relações de ativação entre as porções, diferenças foram identificadas apenas no grupo 3:3 nas relações VM/VL e VM/RF em um número reduzido de repetições. Estes resultados apontam que a coordenação entre as porções sofreu poucas alterações quando comparadas as repetições equivalentes de cada série. Sugere-se que os reduzidos graus de liberdade do movimento utilizado e a progressão da carga de treinamento tenham sido os fatores que conduziram a este resultado

Effect of resistance exercise with different muscle action durations on lactate response / Efeito de protocolos de treinamento com diferentes durações das ações musculares na concentração de lactato sanguíneo

ABSTRACT The aim of this study was to compare the blood lactate concentration in strength training protocols with different muscle action durations in the bench press exercise. Seventeen volunteers performed three protocols with three sets of six repetitions at 60 % of 1RM, three- minute break between sets and different muscle action durations (2-4: 2s concentric and 4s eccentric; 3-3: 3s concentric and 3s eccentric; 4-2: 4s concentric and 2s eccentric). The analysis of blood lactate concentration considered the average values ​​per set in each protocol. The ANOVA two-way of the results showed that the main effect for protocol showed no significant difference between the three protocols (F = 0,75; p = 0,48; power = 0,48; η2 = 0,17), as the interaction among the factors (F = 1,68; p = 0,13; power = 0,09; η2= 0,62). However, there was significant main effect for set (F = 320,23; p = 0,0001; power = 1,00; η2= 0,95). Therefore, resistance training protocols equated with different muscle actions durations shows no differences in blood lactate response and, regardless of the protocol, its concentration increased throughout the three sets performed.

RESUMO O objetivo deste estudo foi comparar a concentração de lactato sanguíneo em protocolos de treinamento de força com diferentes durações das ações musculares no exercício supino. Dezessete voluntários executaram três protocolos com três séries de seis repetições a 60% de 1RM, pausa de três minutos entre as séries e diferentes durações das ações musculares (2-4: 2s concêntrica e 4s excêntrica; 3-3: 3s concêntrica e 3s excêntrica; 4-2: 4s concêntrica e 2s excêntrica). A análise da concentração de lactato sanguíneo considerou os valores médios por série em cada protocolo. Os resultados da ANOVA two-way mostraram que o efeito principal protocolo não apresentou diferença significante entre os três protocolos (F = 0,75; p = 0,48; poder = 0,48; η2 = 0,17), assim como para a interação entre os fatores (F = 1,68; p = 0,13; poder = 0,09; η2 = 0,62). Porém, houve diferença significante na concentração de lactato sanguíneo para o fator série (F = 320,23; p = 0,0001; poder = 1,00; η2 = 0,95). Portanto, protocolos de treinamento de força equiparados com durações das ações musculares distintas não apresentaram diferenças na resposta do lactato sanguíneo e, independentemente do protocolo, a concentração deste substrato aumentou ao longo das três séries realizadas.

Longer repetition duration increases muscle activation and blood lactate response in matched resistance training protocols

This study analyzed the effect of different repetition durations on electromyographic and blood lactate responses of the bench press exercise. Fifteen recreationally trained male volunteers completed two training protocols, matched for intensity (% one-repetition maximum; 1RM), number of sets, number of repetitions, and rest intervals. One of the protocols was performed with a repetition duration of 4 s (2 s concentric: 2 s eccentric; 2:2 protocol), whereas the second protocol had a repetition duration of 6 s (2 s concentric: 4 s eccentric; 2:4 protocol). The results showed higher normalized integrated electromyography (pectoralis major and triceps brachii) for the 2:4 protocol. Blood lactate concentration was also higher in the 2:4 protocol across all sets. These results show that adding 2 s to the eccentric action in matched training protocols increases muscle activation and blood lactate response, which reinforces the notion that increasing repetition duration is an alternative load progression in resistance training.

Efeito da amplitude de movimento no número máximo de repetições no exercício supino livre / Effect of range of motion in the maximum number of repetitions in the bench press exercise / Efectos de la amplitud de movimiento em el número máximo de repeticiones em el ejercicio de supino libre

Pesquisas mostram resultados divergentes no aumento da força utilizando diferentes amplitudes de movimento (ADM). O objetivo deste estudo foi comparar o número máximo de repetições (NMR) no exercício supino com duas ADM. Quatorze voluntários realizaram a familiarização e o teste de uma repetição máxima (1 RM) nas sessões 1 e 2. Nas sessões 3 e 4 realizaram o NMR em quatro séries a 50% de 1 RM, com um minuto de pausa, com ADM parcial (ADMP) e completa (ADMC). Na ADMP utilizou-se metade do deslocamento vertical da barra comparada a condição ADMC. Foi realizada ANOVA "two-way" com medidas repetidas, seguida pelo "Post hoc" Scheffé. Houve diminuição significante do NMR entre as séries, exceto da terceira para a quarta em ambas ADM. Um maior NMR foi verificado para ADMP. A redução da ADM permite a realização de um maior número de repetições para uma mesma intensidade relativa.

There are divergent results about increases in strength using different ranges of motion (ROM). The aim of this study was to compare the maximum number of repetitions (MNR) in bench press with two different ROM. Fourteen subjects performed familiarization and one repetition maximum (1 RM) tests in sessions 1 and 2. MNR in four sets at 50% of 1 RM, one-minute rest with partial (ROMP) and complete ROM (ROMC) were performed in the third and fourth sessions. The ROMP used half of the bar vertical displacement compared to ROMC. Two-way ANOVA with repeated measures was used to compare the experimental conditions, followed by post hoc Scheffe. There was a significant decrease of the MNR among sets, except from third to fourth sets in both ROM. MNR in all sets was higher in ROMP than ROMC. The reduction of ROM allow to perform higher number of repetitions.

Investigaciones cientificas muestran resultados divergentes en el aumento de la fuerza utilizando diferentes amplitudes de movimiento (ADM). El objetivo de este estudio fue comparar el número máximo de repeticiones (NMR) en un ejercicio de supino con dos ADM. Catorce voluntarios realizaron la familiarización y el test de una repetición máxima (1 RM) en las sesiones 1 y 2. En las sesiones 3 y 4 realizaron o NMR en cuatro series a 50% de 1 RM, un minuto de pausa con ADM parcial (ADMP) y completa (ADMC). ADMP utilizó la mitad del desplazamiento vertical de la barra realizado durante la ADMC. Fue aplicada ANOVA "two-way" con medidas repetidas, seguido del "Post hoc" Scheffé. Se encontró disminución significante del NMR a lo largo de las series, excepto de la tercera para la cuarta en ambas ADM, con el mismo patrón de reducción en ambas ADM. El NMR de la ADMP fue mayor que la ADMC. La reducción de ADM interfirió en el volumen de entrenamiento con mayor número de repeticiones realizadas para una misma intensidad relativa.

Comparação do desempenho no teste de uma repetição máxima utilizando dois diferentes protocolos / Comparison of performance in one repetition maximum test using two different protocols

O objetivo do presente estudo foi comparar o desempenho no teste de uma repetição máxima (1RM) utilizando dois diferentes protocolos no exercício supino livre. Dezessete voluntários do sexo masculino treinados na musculação realizaram dois protocolos para determinação do 1RM no exercício supino. No protocolo A o peso deveria ser deslocado durante uma repetição por tentativa até que ocorresse falha na tentativa seguinte. No protocolo B os indivíduos deveriam deslocar o peso por duas repetições em cada tentativa, e o maior peso que poderia ser deslocado até uma falha na ação muscular concêntrica na segunda repetição da tentativa foi considerado como representativo do 1RM. Verificou-se diferença significativa no desempenho entre os protocolos A e B. Esses resultados possibilitam concluir que os protocolos A e B aplicados no teste de 1RM no exercício supino não são intercambiáveis.

The purpose of this study was to compare the performance in one repetition maximum (1RM) testing using two different test protocols in a bench press exercise. A total of 17 weight-trained men performed two protocols to determine the 1RM bench press exercise. In protocol A, the weight should be lifted for one repetition per attempt until fail on the next attempt. In protocol B, subjects should lift the weight for two repetitions in each attempt and the heaviest weight that could be lifted until a concentric muscle action fail at the second repetition was considered as representative of 1RM. Each subject performed the two protocols and the testing order was randomly assigned and balanced between the subjects. Significant difference between protocols A and B was found. The results suggest that protocols A and B using by 1RM testing in bench press exercise were not interchangeable.