Nonuniform Muscle Hypertrophy

Wakahara, Toshihiko; Fukutani, Atsuki; Kawakami, Yasuo; Yanai, Toshimasa

doi:10.1249/mss.0b013e3182995349

Cited by 116 publications

(64 citation statements)

References 22 publications

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“…Studies have reported that changes in morphology (e.g., anatomical cross-sectional area, muscle thickness) and architecture (e.g., fascicle length, pennation angles) in response to resistance training occurs non-uniformly along the length of the muscle [10, 11]. This non-uniform muscle adaptation to resistance exercise is particular true for eccentric training [12].…”

Section: Introductionmentioning

confidence: 99%

“…This non-uniform muscle adaptation to resistance exercise is particular true for eccentric training [12]. The non-uniform change in muscle morphology and architecture after a training intervention has been attributed to the region-specific muscle activation assessed by the transverse relaxation time (T 2 ) of functional magnetic resonance images (fMRI) during the training session [10, 11]. …”

Section: Introductionmentioning

confidence: 99%

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MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players

et al. 2016

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The present study examined site-specific hamstring muscles use with functional magnetic resonance imaging (MRI) in elite soccer players during strength training. Thirty-six players were randomized into four groups, each performing either Nordic hamstring, flywheel leg-curl, Russian belt or the hip-extension conic-pulley exercise. The transverse relaxation time (T2) shift from pre- to post-MRI were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semimembranosus (SM) muscles at proximal, middle and distal areas of the muscle length. T2 values increased substantially after flywheel leg-curl in all regions of the BFl (from 9±8 to 16±8%), BFs (41±6–71±11%), and ST (60±1–69±7%). Nordic hamstring induced a substantial T2 increase in all regions of the BFs (13±8–16±5%) and ST (15±7–17±5%). T2 values after the Russian belt deadlift substantially increased in all regions of the BFl (6±4–7±5%), ST (8±3–11±2%), SM (6±4–10±4%), and proximal and distal regions of BFs (6±6–8±5%). T2 values substantially increased after hip-extension conic-pulley only in proximal and middle regions of BFl (11±5–7±5%) and ST (7±3–12±4%). The relevance of such MRI-based inter- and intra-muscle use in designing more effective resistance training for improving hamstring function and preventing hamstring injuries in elite soccer players should be explored with more mechanistic studies.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players

et al. 2016

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“…Estudos têm associado uma elevada resposta da concentração de lactato sanguíneo com um aumento no recrutamento de unidades motoras rápidas 5,6 , e uma maior resposta hipertrófica 7 . Considerando que as fibras musculares recrutadas durante o treinamento de força estariam suscetíveis à adaptação 8,9 , protocolos que apresentam maior resposta eletromiográfica e concentração sanguínea de lactato teriam maior potencial para promover maiores aumentos na força e hipertrofia muscular 7,10 . A prescrição de um programa de treinamento de força na musculação deve considerar diferentes variáveis, sendo que a manipulação de uma destas variáveis, a duração da repetição, pode interferir na atividade eletromiográfica 4,11,12 e na concentração de lactato sanguíneo 7 .…”

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Effect of Resistance Exercise With Different Muscle Action Durations on Lactate Response

Lima¹,

Costa²,

Lacerda³

et al. 2017

J Phys Educ

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RESUMOO 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; η 2 = 0,17), assim como para a interação entre os fatores (F = 1,68; p = 0,13; poder = 0,09; η 2 = 0,62). Porém, houve diferença significante na concentração de lactato sanguíneo para o fator série (F = 320,23; p = 0,0001; poder = 1,00; η 2 = 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. Palavras-chave: Treinamento de força. Duração da repetição. Lactato sanguíneo. ABSTRACTThe 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; η 2 = 0,17), as the interaction among the factors (F = 1,68; p = 0,13; power = 0,09; η 2 = 0,62). However, there was significant main effect for set (F = 320,23; p = 0,0001; power = 1,00; η 2 = 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. Keywords: Resistance training. Repetition duration. Blood lactate. IntroduçãoO lactato sanguíneo é um subproduto do sistema glicolítico anaeróbico que tem sua concentração alterada de acordo com a exigência metabólica de um exercício 1 . A concentração de lactato sanguíneo vem sendo utilizada como um parâmetro de resposta metabólica proporcionada por diferentes protocolos de treinamento de força [2][3][4] . Estudos têm associado uma elevada resposta da concentração de lactato sanguíneo com um aumento no recrutamento de unidades motoras rápidas ...

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“…Some of these studies have also measured the concentration of blood lactate (Eckhardt et al, 2011;Lacerda et al, 2016;Smilios et al, 2010;Takarada et al, 2000;Walker et al, 2011) because the augmented lactate response has been associated with an increased recruitment of fast-twitch motor units (Gladden, 2004;Moritani, Tanaka, Yoshida, Ishii, Yoshida, & Shindo, 1984). Given the expectation that the activated muscle fibers are those that adapt to training (Spiering et al, 2008;Wakahara, Fukutani, Kawakami, & Yanai, 2013), protocols which show higher electromyographic amplitude would present greater potential to promote increases in strength and muscle hypertrophy (Takarada et al;Watanabe, Madarame, Ogasawara, Nakazato, & Ishii, 2014).…”

Section: Introductionmentioning

confidence: 99%

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

Martins-Costa

Diniz

Lima

et al. 2016

Motriz: rev. educ. fis.

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Abstract--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.

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Nonuniform Muscle Hypertrophy

Abstract: The results suggest that nonuniform muscle hypertrophy after training intervention is due to the region-specific muscle activation during the training session.

Cited by 116 publications

References 22 publications

MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players

MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players

Effect of Resistance Exercise With Different Muscle Action Durations on Lactate Response

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

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