Changes in muscle size, architecture, and neural activation after 20 days of bed rest with and without resistance exercise

Kawakami, Yasuo; Akima, Hiroshi; Kubo, Keishi; Muraoka, Yoshiho; Hasegawa, Hiroshi; Kouzaki, Motoki; Imai, Morihiro; Suzuki, Yoshio; Gunji, Atsuko; Kanehisa, Hiroaki; Fukunaga, Tetsuo

doi:10.1007/s004210000330

Cited by 186 publications

(196 citation statements)

References 22 publications

Supporting

Mentioning

160

Contrasting

Unclassified

Order By: Relevance

“…Bed rest studies have shown a decrease in the root mean square (RMS) of EMG of 6.5% after 20 days (Kawakami et al, 2001) and 19% after 42 days (Edgerton et al, 2001). Nevertheless, the contribution of reduced neural drive to the loss of muscle strength associated with disuse seems still an unresolved issue as several studies showed no change in maximal EMG activity in both vastus lateralis (de Boer et al, 2007) and plantar flexor muscles (Seynnes et al) after ULLS, whilst others (Clark et al 2006a) showed a 30% decrease in compound muscle action potential (CMAP).…”

Section: Introductionmentioning

confidence: 99%

Skeletal muscle adaptations to physical inactivity and subsequent retraining in young men

et al. 2013

View full text Add to dashboard Cite

Narici, M. V. (2013). Skeletal muscle adaptations to physical inactivity and subsequent retraining in young men. Biogerontology (Dordrecht), 14,(247)(248)(249)(250)(251)(252)(253)(254)(255)(256)(257)(258)(259) Dette er siste tekst-versjon av artikkelen, og den kan inneholde små forskjeller fra forlagets pdf-versjon. Forlagets pdf-versjon finner du på link.springer.com: http://dx.doi.org/10. 1007/s10522-013-9427-6 This is the final text version of the article, and it may contain minor differences from the journal's pdf version. The original publication is available at link.springer.com: http://dx.doi.org/10.1007/s10522-013-9427-6 AbstractSkeletal muscle structure and function are markedly affected by chronic disuse. With unloading, muscle mass is lost at rate of about 0.4%/day but little is known about the recovery of muscle mass and strength following disuse. Here we report an extensive data set describing in detail skeletal muscle adaptations in structure and function in response to both disuse and retraining. Eight young men (23±2.2 yrs) underwent 3 weeks of unilateral lower limb suspension (ULLS) followed by a 3-week resistance training recovery program. Knee extensor (KE) isometric torque, voluntary activation (VA), quadriceps femoris (QF) muscle volume (QF vol ), fascicle length (Lf) and pennation angle (θ), physiological cross-sectional area (PCSA) of all four heads of the QF muscle, were measured before, after ULLS, and post-ULLS-resistance training. Needle biopsies were taken from the vastus lateralis muscle of a subgroup (n=6) of the same subjects and cross sectional area of individual muscle s and myosin content of muscle samples were determined. Following 3 weeks of ULLS, isometric torque decreased by 26%, PCSA by 3%, QF vol by 10%. Lf and θ of all four heads of QF significantly decreased (P≤0.05). Following the 3-week retraining period, isometric torque, PCSA, QF vol , Lf and θ of all four heads of QF were all fully restored to pre ULLS values. CSA of individual muscle fibres and myosin content of muscle samples decreased by 26% and 35% respectively (post-ULLS) and recovered to almost pre-ULLS values following retraining. There were no significant changes in voluntary activation of the quadriceps muscles in response to either ULLS or subsequent retraining. These results indicate that, 1) the loss of muscle force with 3-week unloading in humans is mostly explained by muscle atrophy and by a decrease in myosin content and, 2) all the neuromuscular changes induced by this model of disuse can be fully restored after a resistance training intervention of equal duration. KeywordsDisuse, Skeletal muscle, atrophy, recovery, resistance training 2 Introduction Deficits in skeletal muscle mass and function are primary outcomes of chronic unloading, with antigravity muscles such as the knee extensors (KE) being particularly affected (Narici and De Boer 2011). An extensive knowledge of these adverse conditions is paramount, for they are inevitably linked to clinical situations such as prolonged best rest or ...

show abstract

Section: Introductionmentioning

confidence: 99%

Skeletal muscle adaptations to physical inactivity and subsequent retraining in young men

et al. 2013

View full text Add to dashboard Cite

show abstract

“…O VL é um músculo penado, superficial e de arquitetura pouco complexa (BLAZEVICH 2007a). Dessa forma, é frequentemente analisado em estudos com US (KAWAKAMI et al, 2001;KUBO et al, 2003;REEVES et al, 2004;KAWAKAMI, et al, 2006;MAGANARIS et al, 2006; BLAZEVICH et al, 2007a;BLAZEVICH et al, 2007b; BRANCACCIO et al, 2008;DE BOER et al, 2008;REEVES et al, 2009; BLAZEVICH et al, 2009).…”

Section: Doi: Confiabilidade Do Vasto Lateralunclassified

Section: Procedimentounclassified

“…O músculo analisado pertencia ao dimídio direito. Primeiramente, foi medido o comprimento da coxa (distância entre o trocânter maior do fêmur a interlinha articular do joelho), e em seguida, marcada a região de 50% deste comprimento (ABE et al, 2001;KAWAKAMI et al, 2001;KAWAKAMI et al, 2006; BLAZEVICH et al, 2007a; BLAZEVICH et al, 2009), lateralmente à coxa.Após a marcação em ortostatismo, os indivíduos foram posicionados em decúbito dorsal com os membros inferiores em extensão e relaxados, permanecendo aproximadamente 10 minutos de repouso nesta posição. Para (figura 1) foi considerada a distância longitudinal entre a aponeurose profunda e superficial do músculo.…”

unclassified

See 1 more Smart Citation

Confiabilidade das medidas de arquitetura do músculo Vasto Lateral pela ultrassonografia

Lima

Oliveira

2013

Motriz: rev. educ. fis.

View full text Add to dashboard Cite

Resumo: As medidas de confiabilidade das análises da arquitetura muscular pela ultrasonografia são importantes referências para estudos aplicados de mecânica muscular. O objetivo deste estudo foi determinar a confiabilidade das medidas de espessura muscular (EM), ângulo de penação (AP) e comprimento da fibra (CF) do músculo Vasto Lateral (VL). As imagens de ultrassom foram obtidas em um grupo (N=14; 22 ± 1,75 anos) em duas visitas (sessenta medidas por indivíduo). Foi calculado o coeficiente de correlação intraclasse (CCI), coeficiente de variação (CV) e erro típico da medida (ETM). Os resultados demonstram alta confiabilidade: CCI AP (0,83 a 0,99), EM (0,96 a 0,99) e CF (0,80 a 0,99); CV AP (3,68 a 6,34%), EM (3,12 a 3,84%) e CF (3,98 a 6,33%) e ETM AP (0,18 a 0,59º); EM (0,014 a 0,15mm) e CF (0,07 a 1,47mm). Essas medidas devem ser consideradas em estudos que analisam o impacto na arquitetura muscular em programas de condicionamento do Vasto Lateral. Palavras-chave: Confiabilidade. Vasto Lateral. Ultrassom. Arquitetura Muscular. Reliability of the measurements of architecture of the Vastus Lateralis muscle by ultrasonographyAbstract: Reliability of the measurements of the muscle architecture variables by ultrasound are important references for applied studies of muscle mechanics. The aim this study was to analyze the reliability of measurements of Vastus Lateralis (VL) muscle thickness (MT), pennation angle (PA) and fiber length (FL). Ultrasound images were obtained in two days (N=14, 22 ± 1,75 years) with a total of sixty measurements in each subject. Reliability was determined by intraclass correlation coefficient (ICC), coefficient of variation (CV) and typical error of measurement (TEM). Results show high reliability: MT (0,96 a 0,99), PA (0,83 a 0,99) and FL (0,80 a 0,99) ICC; MT (3,12 a 3,84%), PA (3,68 a 6,34%) and FL (3,98 a 6,33%) CV; MT (0,014 a 0,15mm), PA (0,18 a 0,59º) and FL (0,07 a 1,47mm) TEM. These measures should be considered in studies of the impact of conditioning programs in the architecture of the vastus lateralis muscle. Keywords: Reliability. Vastus Lateralis. Ultrasound. Muscle Architecture. doi: Confiabilidade do Vasto LateralMotriz, Rio Claro, v.19, n.1, p.217-223, jan./mar. 2013 218 , ou, in vivo, com técnicas de imagem, como a ressonância magnética (RM) (MIYATANI et al, 2004, AKIMA et al., 2000, VORONOV, 2003 e a ultrassonografia (US). A US vem ganhando importância por ser considerada uma técnica de medida confiável e de baixo custo para aquisição de imagens do tecido muscular, ósseo e adiposo (BEMBEM, 2002, MIYATANI et al., 2002, NOORKOIV et al., 2010, GOMES et al., 2010. Dos músculos que têm sido avaliados, destacam-se os dos membros inferiores como Gastrocnêmios (MORSE et al., 2005), Bíceps Femoral (CHLEBOUN et al., 2001), Reto Femoral (SEYMOUR et al., 2009, BEMBEM, 2002 e Vasto Lateral (VL). O VL é um músculo penado, superficial e de arquitetura pouco complexa (BLAZEVICH 2007a). Dessa forma, é frequentemente analisado em estudos com US (KAWAKAMI et al., 2001;KUBO et al....

show abstract

“…One must consider the benefits of exercise, the benefits of exercise during pregnancy, the possible detrimental effects of activity restriction, and the feasibility of exercising in a hospital setting before incorporating a bedrest-exercise intervention program for activity restricted antenatal women. The benefits of incorporating a bedrest-exercise program have yet to be fully investigated in the antepartum hospitalized population, but are well documented in the non pregnant population [20][21][22][23][24]. The first study was conducted in 1992, by Mayberry and colleges, in order to assess the short-term effects of controlled bed-rested exercise on uterine activity of women diagnosed with preterm labour [25].…”

Section: Introductionmentioning

confidence: 99%

Feasibility of incorporating a bed-rest exercise program during a twin pregnancy: Case reports

Brun¹,

Hammond²,

Mottola³

2012

OJOG

View full text Add to dashboard Cite

Considering the maternal risk for both short-and long-term disability imposed by activity restriction, it is of great concern that the antepartum symptoms of bed rest are still evident in the postpartum period. The benefits of bed-rest-exercise may alleviate or even prevent physiological distresses or deconditioning associated with activity restriction, thus, eliminating or stabilizing, factors that may augment existing complications. This is the first study to investigate the feasibility of incorporating a bed-rest exercise program in a specific hospitalized twin pregnancy case. The maternal physiological responses of heart rate, blood pressure and uterine contractions to a four week bed-rest resistance program were measured in a woman hospitalized due to complications during her twin pregnancy. A second participant (same diagnoses) was included as a control. The bedrest-exercise reduced the degree of swelling in the lower extremities, promoted more energy during the day and a better night's sleep. There were no significant differences in uterine contractions pre vs post protocol and all babies were born healthy.

show abstract

Changes in muscle size, architecture, and neural activation after 20 days of bed rest with and without resistance exercise

Cited by 186 publications

References 22 publications

Skeletal muscle adaptations to physical inactivity and subsequent retraining in young men

Skeletal muscle adaptations to physical inactivity and subsequent retraining in young men

Confiabilidade das medidas de arquitetura do músculo Vasto Lateral pela ultrassonografia

Feasibility of incorporating a bed-rest exercise program during a twin pregnancy: Case reports

Contact Info

Product

Resources

About