scholarly journals The Effect of Strength Training on Vastus Lateralis’ Stiffness: An Ultrasound Quasi-Static Elastography Study

2020 ◽  
Vol 17 (12) ◽  
pp. 4381 ◽  
Author(s):  
Rute Santos ◽  
Maria João Valamatos ◽  
Pedro Mil-Homens ◽  
Paulo Armada-da-Silva
Keyword(s):  
Skeletal Muscle ◽  
Strength Training ◽  
Ultrasound Imaging ◽  
Sports Medicine ◽  
Vastus Lateralis ◽  
Young Male ◽  
Training Group ◽  
Muscle Stiffness ◽  
Ultrasound Elastography ◽  
Knee Extensors

Ultrasound imaging allows the evaluation of musculoskeletal morphology and function. Ultrasound elastography can also offer semi-quantitative and/or quantitative assessment of tissue stiffness providing relevant information about adaptations of skeletal muscle mechanical properties. In this study we aimed to explore the feasibility of elastography ultrasound imaging in assessing the effect of strength training on vastus lateralis stiffness. Twenty-eight young male adults were separated in a control (n = 9) and strength-training (n = 20) groups. The strength-training group completed 15 weeks of either concentric (n = 10) or eccentric (n = 10) isokinetic training of the knee extensors. Ultrasound scans of the vastus lateralis for quasi-static elastography were collected. All image acquisitions and measurements were done by the same experienced sonographer. After 15 weeks, knee maximal extension isometric torque increased in the strength-training groups. After strength training, there was a decrease in the amount of red pixels in vastus lateralis region of interest [F(1,18) = 25.490; p < 0.001; η2 = 0.586], whereas the amount of green and blue pixels increased F(1,18) = 17.179; p < 0.01; η2 = 0.488; F(1,18) = 6.522; p < 0.05; η2 = 0.266], suggesting higher vastus lateralis stiffness. We conclude that concentric and eccentric strength training increases skeletal muscle stiffness, which can be evaluated by quasi-static elastography. Ultrasound elastography is suitable for non-invasive evaluation of skeletal muscle functional adaptations, which can be of importance for sports medicine and in designing optimal training and rehabilitation programs.

Strength training counteracts motor performance losses during bed rest

2003 ◽  
Vol 95 (4) ◽  
pp. 1485-1492 ◽  
Author(s):  
Minoru Shinohara ◽  
Yasuhide Yoshitake ◽  
Motoki Kouzaki ◽  
Hideoki Fukuoka ◽  
Tetsuo Fukunaga
Keyword(s):  
Strength Training ◽  
Muscle Activation ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Bed Rest ◽  
Training Group ◽  
Medial Gastrocnemius ◽  
Knee Extensors ◽  
Extensor Muscles ◽  
Muscle Groups

The purpose of the study was to determine the effect of bed rest with or without strength training on torque fluctuations and activation strategy of the muscles. Twelve young men participated in a 20-day bed rest study. Subjects were divided into a non-training group (BRCon) and a strength-training group (BRTr). The training comprised dynamic calf-raise and leg-press exercises. Before and after bed rest, subjects performed maximal contractions and steady submaximal isometric contractions of the ankle extensor muscles and of the knee extensor muscles (2.5-10% of maximal torque). Maximal torque decreased for both the ankle extensors (9%, P < 0.05) and knee extensors (16%, P < 0.05) in BRCon but not in BRTr. For the ankle extensors, the coefficient of variation (CV) for torque increased in both groups ( P < 0.05), with a greater amount ( P < 0.05) in BRCon (88%) compared with BRTr (41%). For the knee extensors, an increase in the CV for torque was observed only in BRCon (22%). The increase in the CV for torque in BRCon accompanied the greater changes in electromyogram amplitude of medial gastrocnemius (122%) and vastus lateralis (59%) compared with BRTr ( P < 0.05). The results indicate that fluctuations in torque during submaximal contractions of the extensor muscles in the leg increase after bed rest and that strength training counteracted the decline in performance. The response varied across muscle groups. Alterations in muscle activation may lead to an increase in fluctuations in motor output after bed rest.

scholarly journals Blood flow-restricted strength training displays high functional and biological efficacy in women: a within-subject comparison with high-load strength training

2015 ◽  
Vol 309 (7) ◽  
pp. R767-R779 ◽  
Author(s):  
Stian Ellefsen ◽  
Daniel Hammarström ◽  
Tor A. Strand ◽  
Erika Zacharoff ◽  
Jon E. Whist ◽  
...  
Keyword(s):  
Blood Flow ◽  
Strength Training ◽  
Vastus Lateralis ◽  
Quadriceps Femoris ◽  
Knee Extensors ◽  
Skeletal Muscle Function ◽  
Heavy Load ◽  
Cross Sectional ◽  
Musculus Quadriceps Femoris ◽  
Musculus Quadriceps

Limited data exist on the efficacy of low-load blood flow-restricted strength training (BFR), as compared directly to heavy-load strength training (HST). Here, we show that 12 wk of twice-a-week unilateral BFR [30% of one repetition maximum (1RM) to exhaustion] and HST (6-10RM) of knee extensors provide similar increases in 1RM knee extension and cross-sectional area of distal parts of musculus quadriceps femoris in nine untrained women (age 22 ± 1 yr). The two protocols resulted in similar acute increases in serum levels of human growth hormone. On the cellular level, 12 wk of BFR and HST resulted in similar shifts in muscle fiber composition in musculus vastus lateralis, evident as increased MyHC2A proportions and decreased MyHC2X proportions. They also resulted in similar changes of the expression of 29 genes involved in skeletal muscle function, measured both in a rested state following 12 wk of training and subsequent to singular training sessions. Training had no effect on myonuclei proportions. Of particular interest, 1) gross adaptations to BFR and HST were greater in individuals with higher proportions of type 2 fibers, 2) both BFR and HST resulted in approximately four-fold increases in the expression of the novel exercise-responsive gene Syndecan-4, and 3) BFR provided lesser hypertrophy than HST in the proximal half of musculus quadriceps femoris and also in CSApeak, potentially being a consequence of pressure from the tourniquet utilized to achieve blood flow restriction. In conclusion, BFR and HST of knee extensors resulted in similar adaptations in functional, physiological, and cell biological parameters in untrained women.

Resistance training affects GLUT-4 content in skeletal muscle of humans after 19 days of head-down bed rest

1999 ◽  
Vol 86 (3) ◽  
pp. 909-914 ◽  
Author(s):  
Izumi Tabata ◽  
Youji Suzuki ◽  
Tetsuo Fukunaga ◽  
Toshiko Yokozeki ◽  
Hiroshi Akima ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Resistance Training ◽  
Membrane Protein ◽  
Vastus Lateralis ◽  
Bed Rest ◽  
Training Group ◽  
Control Group ◽  
Glut 4 ◽  
Before And After ◽  
Voluntary Contractions

This study assessed the effects of inactivity on GLUT-4 content of human skeletal muscle and evaluated resistance training as a countermeasure to inactivity-related changes in GLUT-4 content in skeletal muscle. Nine young men participated in the study. For 19 days, four control subjects remained in a −6° head-down tilt at all times throughout bed rest, except for showering every other day. Five training group subjects also remained at bed rest, except during resistance training once in the morning. The resistance training consisted of 30 isometric maximal voluntary contractions for 3 s each; leg-press exercise was used to recruit the extensor muscles of the ankle, knee, and hip. Pauses (3 s) were allowed between bouts of maximal contraction. Muscle biopsy samples were obtained from the lateral aspect of vastus lateralis (VL) muscle before and after the bed rest. GLUT-4 content in VL muscle of the control group was significantly decreased after bed rest (473 ± 48 vs. 398 ± 66 counts ⋅ min−1 ⋅ μg membrane protein−1, before and after bed rest, respectively), whereas GLUT-4 significantly increased in the training group with bed rest (510 ± 158 vs. 663 ± 189 counts ⋅ min−1 ⋅ μg membrane protein−1, before and after bed rest, respectively). The present study demonstrated that GLUT-4 in VL muscle decreased by ∼16% after 19 days of bed rest, and isometric resistance training during bed rest induced a 30% increase above the value of GLUT-4 before bed rest.

Skeletal muscle cytochrome c and myoglobin, endurance, and frequency of training

1981 ◽  
Vol 51 (3) ◽  
pp. 746-749 ◽  
Author(s):  
R. C. Hickson
Keyword(s):  
Skeletal Muscle ◽  
Cytochrome C ◽  
Vastus Lateralis ◽  
Training Group ◽  
Treadmill Running ◽  
Female Rats ◽  
Time To Exhaustion ◽  
Training Frequency ◽  
Muscle Types ◽  
Fast Twitch

This study was undertaken to evaluate the effects of various training frequencies on performance capacity, the mitochondrial marker cytochrome c, and myoglobin, which is responsible for storage and transport of O2, in the three types of skeletal muscle. Female rats were trained by treadmill running up to 120 min/day, either 2, 4, or 6 days/wk for 14 wk. As a result of training, exercise time to exhaustion was increased in proportion to the number of training sessions per week. Cytochrome c concentration increased (range 20–90%) as a linear function of the number of exercises per week in the fast-twitch red vastus lateralis (FTR), the slow-twitch soleus (STR), and the mixed plantaris muscles. However, the concentration of cytochrome c in fast-twitch white vastus lateralis (FTW) muscles increased to approximately the same extent (40–50%) in all training groups. The increases in myoglobin concentration (13–45%) with training were significantly related to frequency in FTR muscle but not in STR muscle. Myoglobin levels in FTW muscle remained unchanged, regardless of training group. These results provide evidence that the capacity to perform endurance exercise and the mitochondrial content of the red skeletal muscle types are directly affected by training frequency.

scholarly journals Exercise Training Enhances Angiogenesis-Related Gene Responses in Skeletal Muscle of Patients with Chronic Heart Failure

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1915
Author(s):  
Andrea Tryfonos ◽  
Giorgos Tzanis ◽  
Theodore Pitsolis ◽  
Eleftherios Karatzanos ◽  
Michael Koutsilieris ◽  
...  
Keyword(s):  
Heart Failure ◽  
Skeletal Muscle ◽  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Strength Training ◽  
Vastus Lateralis ◽  
Vastus Lateralis Muscle ◽  
Vascular Endothelial ◽  
Related Factors ◽  
Endothelial Growth Factor

Peripheral myopathy consists of a hallmark of heart failure (HF). Exercise enhanced skeletal muscle angiogenesis, and thus, it can be further beneficial towards the HF-induced myopathy. However, there is limited evidence regarding the exercise type that elicits optimum angiogenic responses of skeletal muscle in HF patients. This study aimed to (a) compare the effects of a high-intensity-interval-training (HIIT) or combined HIIT with strength training (COM) exercise protocol on the expression of angiogenesis-related factors in skeletal muscle of HF patients, and (b) examine the potential associations between the expression of those genes and capillarization in the trained muscles. Thirteen male patients with chronic HF (age: 51 ± 13 y; BMI: 27 ± 4 kg/m2) were randomly assigned to a 3-month exercise program that consisted of either HIIT (N = 6) or COM training (N = 7). Vastus lateralis muscle biopsies were performed pre- and post-training. RT-PCR was used to quantify the fold changes in mRNA expression of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR-2), hypoxia-inducible factor 1 alpha (HIF-1α), angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2), angiopoietin receptor (Tie2), and matrix metallopeptidase 9 (MMP-9), and immunohistochemistry to assess capillarization in skeletal muscle post-training. There was an overall increase in the expression levels of VEGF, VEGFR-2, HIF-1α, Ang2, and MMP9 post-training, while these changes were not different among groups. Changes in capillary-to-fibre ratio were found to be strongly associated with Tie2 and HIF-1α expression. This was the first study demonstrating that both HIIT and combined HIIT with strength training enhanced similarly the expression profile of angiogenic factors in skeletal muscle of HF patients, possibly driving the angiogenic program in the trained muscles, although those gene expression increases were found to be only partially related with muscle capillarization.

scholarly journals Effect of resistance training on skeletal muscle-specific force in elderly humans

2004 ◽  
Vol 96 (3) ◽  
pp. 885-892 ◽  
Author(s):  
N. D. Reeves ◽  
M. V. Narici ◽  
C. N. Maganaris
Keyword(s):  
Skeletal Muscle ◽  
Strength Training ◽  
Old Age ◽  
Vastus Lateralis ◽  
Muscle Volume ◽  
Electromyographic Activity ◽  
Specific Force ◽  
Fascicle Length ◽  
Leg Extension ◽  
Muscle Fascicle

This study assessed muscle-specific force in vivo following strength training in old age. Subjects were assigned to training ( n = 9, age 74.3 ± 3.5 yr; mean ± SD) and control ( n = 9, age 67.1 ± 2 yr) groups. Leg-extension and leg-press exercises (2 sets of 10 repetitions at 80% of the 5 repetition maximum) were performed three times/wk for 14 wk. Vastus lateralis (VL) muscle fascicle force was calculated from maximal isometric voluntary knee extensor torque with superimposed stimuli, accounting for the patella tendon moment arm length, ultrasound-based measurements of muscle architecture, and antagonist cocontraction estimated from electromyographic activity. Physiological cross-sectional area (PCSA) was calculated from the ratio of muscle volume to fascicle length. Specific force was calculated by dividing fascicle force by PCSA. Fascicle force increased by 11%, from 847.9 ± 365.3 N before to 939.3 ± 347.8 N after training ( P < 0.05). Due to a relatively greater increase in fascicle length (11%) than muscle volume (6%), PCSA remained unchanged (pretraining: 30.4 ± 8.9 cm2; posttraining: 29.1 ± 8.4 cm2; P > 0.05). Activation capacity and VL muscle root mean square electromyographic activity increased by 5 and 40%, respectively, after training ( P < 0.05), indicating increased agonist neural drive, whereas antagonist cocontraction remained unchanged ( P > 0.05). The VL muscle-specific force increased by 19%, from 27 ± 6.3 N/cm2 before to 32.1 ± 7.4 N/cm2 after training ( P < 0.01), highlighting the effectiveness of strength training for increasing the intrinsic force-producing capacity of skeletal muscle in old age.

scholarly journals Application of the novel estimation method by shear wave elastography using vibrator to human skeletal muscle

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wakako Tsuchida ◽  
Yoshiki Yamakoshi ◽  
Shingo Matsuo ◽  
Mayu Asakawa ◽  
Keita Sugahara ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Shear Wave ◽  
Human Skeletal Muscle ◽  
Estimation Method ◽  
Shear Wave Elastography ◽  
Muscle Stiffness ◽  
Ultrasound Elastography ◽  
The Novel ◽  
Wave Velocities ◽  
Shear Wave Velocities

AbstractIn recent years, non-invasive measurement of tissue stiffness (hardness) using ultrasound elastography has attracted considerable attention. It has been used to evaluate muscle stiffness in the fields of rehabilitation, sports, and orthopedics. However, ultrasonic diagnostic devices with elastography systems are expensive and clinical use of such devices has been limited. In this study, we proposed a novel estimation method for vibration-based shear wave elastography measurement of human skeletal muscle, then determined its reproducibility and reliability. The coefficient of variation and correlation coefficient were used to determine reproducibility and reliability of the method by measuring the shear wave velocities in konjac phantom gels and agar phantom gels, as well as skeletal muscle. The intra-day, day-to-day, and inter-operator reliabilities were good when measuring the shear wave velocities in phantom gels. The intra-day and day-to-day reliabilities were good when measuring the shear wave velocities in skeletal muscle. The findings confirmed adequate reproducibility and reliability of the novel estimation method for vibration-based shear wave elastography. Therefore, the proposed measurement method may be a useful tool for evaluation of muscle stiffness.

Proteomic identification of secreted proteins from human skeletal muscle cells and expression in response to strength training

2011 ◽  
Vol 301 (5) ◽  
pp. E1013-E1021 ◽  
Author(s):  
Frode Norheim ◽  
Truls Raastad ◽  
Bernd Thiede ◽  
Arild C. Rustan ◽  
Christian A. Drevon ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Strength Training ◽  
Skeletal Muscles ◽  
Human Skeletal Muscle ◽  
Vastus Lateralis ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Secreted Proteins ◽  
Human Myotubes ◽  
Human Skeletal Muscle Cells

Regular physical activity protects against several types of diseases. This may involve altered secretion of signaling proteins from skeletal muscle. Our aim was to identify the most abundantly secreted proteins in cultures of human skeletal muscle cells and to monitor their expression in muscles of strength-training individuals. A total of 236 proteins were detected by proteome analysis in medium conditioned by cultured human myotubes, which was narrowed down to identification of 18 classically secreted proteins expressed in skeletal muscle, using the SignalP 3.0 and Human Genome Expression Profile databases together with a published mRNA-based reconstruction of the human skeletal muscle secretome. For 17 of the secreted proteins, expression was confirmed at the mRNA level in cultured human myotubes as well as in biopsies of human skeletal muscles. RT-PCR analyses showed that 15 of the secreted muscle proteins had significantly enhanced mRNA expression in m. vastus lateralis and/or m. trapezius after 11 wk of strength training among healthy volunteers. For example, secreted protein acidic and rich in cysteine, a secretory protein in the membrane fraction of skeletal muscle fibers, was increased 3- and 10-fold in m. vastus lateralis and m. trapezius, respectively. Identification of proteins secreted by skeletal muscle cells in vitro facilitated the discovery of novel responses in skeletal muscles of strength-training individuals.

Skeletal Muscle Function in Young Patients With Cystic Fibrosis

2016 ◽  
Vol 28 (3) ◽  
pp. 364-373 ◽  
Author(s):  
Lothar Stein ◽  
Constanze Pacht ◽  
Sibylle Junge ◽  
Tobias S. Kaeding ◽  
Momme Kück ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cystic Fibrosis ◽  
Muscle Function ◽  
Vastus Lateralis ◽  
Young Patients ◽  
Forced Expiratory Volume ◽  
Knee Extensors ◽  
Emg Activity ◽  
Skeletal Muscle Function ◽  
M Wave

Purpose:Defects in the gene encoding the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) cause CF. Absence of the CFTR may result in skeletal muscle dysfunction. Here, we tested skeletal muscle function in male adolescent patients with CF.Methods:Ten CF and 10 control participants (age: 16.8 ± 0.6 years) performed 7 repetitive sets of maximum voluntary contractions (MVCs) and underwent an isometric fatigue test of the knee extensors. Electromyography (EMG) activity was recorded from the m. vastus lateralis (VL) and m. vastus medialis (VM).Results:In CF, the MVC torque was lower and correlated with the predicted forced expiratory volume in one second (r = .73, p = .012, n = 10). The M-wave in the VL was shorter in CF than in controls (18.6 ± 0.5 vs. 20.3 ± 0.5 ms, p < .028). In the VM, both the M-wave (4.96 ± 0.61 vs. 7.97 ± 0.60 mV, p = .001) and the EMG (0.29 ± 0.04 vs. 0.47 ± 0.04 mV, p = .004) amplitudes were smaller in CF.Conclusion:The differences in the VL and VM EMG signals between the groups indicate that the lower MVC torque in CF did not result from the direct impact of a CFTR defect on the sarcolemmal excitability; the differences more likely resulted from the less developed musculature in the patients with CF.

scholarly journals Artificial gravity as a countermeasure to microgravity: a pilot study examining the effects on knee extensor and plantar flexor muscle groups

2009 ◽  
Vol 107 (1) ◽  
pp. 39-46 ◽  
Author(s):  
V. J. Caiozzo ◽  
F. Haddad ◽  
S. Lee ◽  
M. Baker ◽  
William Paloski ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Biopsy ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Bed Rest ◽  
Artificial Gravity ◽  
Knee Extensors ◽  
Plantar Flexors ◽  
Flexor Muscle ◽  
Cross Sectional

The goal of this project was to examine the effects of artificial gravity (AG) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) group ( n = 7) and 2) an AG group ( n = 8), which was subjected to 21 days of 6° head-down tilt bed rest plus daily 1-h exposures to AG (2.5 G at the feet). Centrifugation was produced using a short-arm centrifuge with the foot plate ∼220 cm from the center of rotation. The torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre- and posttreatment. Muscle biopsy samples obtained from the vastus lateralis and soleus muscles were used for a series of gene expression analyses (mRNA abundance) of key factors implicated in the anabolic vs. catabolic state of the muscle. Post/pre torque-velocity determinations revealed greater decrements in knee extensor performance in the BR vs. AG group ( P < 0.04). The plantar flexors of the AG subjects actually demonstrated a net gain in the torque-velocity relationship, whereas in the BR group, the responses declined (AG vs. BR, P < 0.001). Muscle fiber cross-sectional area decreased by ∼20% in the BR group, whereas no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity were higher in the AG group, whereas catabolic markers were elevated in the BR group. Importantly, these patterns were seen in both muscles. We conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading.

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