scholarly journals The Effects of Short-Term Resistance Training and Subsequent Detraining on Neuromuscular Function, Muscle Cross-Sectional Area, and Lean Mass

2022 ◽  
Author(s):  
Pablo B. Costa ◽  
Trent J. Herda ◽  
Ashley A. Herda ◽  
Joel T. Cramer
Keyword(s):  
Resistance Training ◽  
Lean Mass ◽  
Neuromuscular Function ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Short Term ◽  
Cross Sectional ◽  
Muscle Cross Sectional Area

Early resistance training-induced increases in muscle cross-sectional area are concomitant with edema-induced muscle swelling

2015 ◽  
Vol 116 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Felipe Damas ◽  
Stuart M. Phillips ◽  
Manoel E. Lixandrão ◽  
Felipe C. Vechin ◽  
Cleiton A. Libardi ◽  
...  
Keyword(s):  
Resistance Training ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Muscle Cross Sectional Area

Changes in the human muscle force-velocity relationship in response to resistance training and subsequent detraining

2005 ◽  
Vol 99 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Lars L. Andersen ◽  
Jesper L. Andersen ◽  
S. Peter Magnusson ◽  
Charlotte Suetta ◽  
Jørgen L. Madsen ◽  
...  
Keyword(s):  
Resistance Training ◽  
Knee Extension ◽  
Limb Movement ◽  
Cross Sectional Area ◽  
Contractile Properties ◽  
Type I ◽  
Maximal Velocity ◽  
Sectional Area ◽  
Cross Sectional ◽  
Muscle Cross Sectional Area

Previous studies show that cessation of resistance training, commonly known as “detraining,” is associated with strength loss, decreased neural drive, and muscular atrophy. Detraining may also increase the expression of fast muscle myosin heavy chain (MHC) isoforms. The present study examined the effect of detraining subsequent to resistance training on contractile performance during slow-to-medium velocity isokinetic muscle contraction vs. performance of maximal velocity “unloaded” limb movement (i.e., no external loading of the limb). Maximal knee extensor strength was measured in an isokinetic dynamometer at 30 and 240°/s, and performance of maximal velocity limb movement was measured with a goniometer during maximal unloaded knee extension. Muscle cross-sectional area was determined with MRI. Electromyographic signals were measured in the quadriceps and hamstring muscles. Twitch contractions were evoked in the passive vastus lateralis muscle. MHC isoform composition was determined with SDS-PAGE. Isokinetic muscle strength increased 18% ( P < 0.01) and 10% ( P < 0.05) at slow and medium velocities, respectively, along with gains in muscle cross-sectional area and increased electromyogram in response to 3 mo of resistance training. After 3 mo of detraining these gains were lost, whereas in contrast maximal unloaded knee extension velocity and power increased 14% ( P < 0.05) and 44% ( P < 0.05), respectively. Additionally, faster muscle twitch contractile properties along with an increased and decreased amount of MHC type II and MHC type I isoforms, respectively, were observed. In conclusion, detraining subsequent to resistance training increases maximal unloaded movement speed and power in previously untrained subjects. A phenotypic shift toward faster muscle MHC isoforms (I → IIA → IIX) and faster electrically evoked muscle contractile properties in response to detraining may explain the present results.

UPPER BODY RESISTANCE TRAINING IN WOMEN INCREASES ARM MUSCLE CROSS-SECTIONAL AREA BY A 20% AVERAGE

1999 ◽  
Vol 31 (Supplement) ◽  
pp. S325
Author(s):  
L. A. Gotshalk ◽  
B. C. Nindl ◽  
R. U. Newton ◽  
S. J. Fleck ◽  
K. H??kkinen ◽  
...  
Keyword(s):  
Resistance Training ◽  
Cross Sectional Area ◽  
Upper Body ◽  
Sectional Area ◽  
Cross Sectional ◽  
Body Resistance ◽  
Muscle Cross Sectional Area

Sex-based differences in skeletal muscle function and morphology with short-term limb immobilization

2005 ◽  
Vol 99 (3) ◽  
pp. 1085-1092 ◽  
Author(s):  
Nobuo Yasuda ◽  
Elisa I. Glover ◽  
Stuart M. Phillips ◽  
Robert J. Isfort ◽  
Mark A. Tarnopolsky
Keyword(s):  
Muscle Strength ◽  
Lean Mass ◽  
Muscle Function ◽  
Knee Extensor ◽  
Quadriceps Femoris ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Short Term ◽  
Cross Sectional ◽  
Time Points

The purpose of this study was to determine the effects of short-term (14-day) unilateral leg immobilization using a simple knee brace (60° flexion)- or crutch-mediated model on muscle function and morphology in men (M, n = 13) and women (W, n = 14). Isometric and isokinetic (concentric-slow, 0.52 rad/s and fast, 5.24 rad/s) knee extensor peak torque was determined at three time points (Pre, Day-2, and Day-14). At the same time points, magnetic resonance imaging was used to measure the cross-sectional area of the quadriceps femoris and dual-energy X-ray absorptiometry scanning was used to calculate leg lean mass. Muscle biopsies were taken from vastus lateralis at Pre and Day-14 for myosin ATPase and myosin heavy chain analysis. Women showed greater decreases (Pre vs. Day-14) compared with men in specific strength (N/cm2) for isometric [M = 3.1 ± 13.3, W = 17.1 ± 15.9%; P = 0.055 (mean ± SD)] and concentric-slow (M = 4.7 ± 11.3, W = 16.6 ± 18.4%; P < 0.05) contractions. There were no immobilization-induced sex-specific differences in the decrease in quadriceps femoris cross-sectional area (M = 5.7 ± 5.0, W = 5.9 ± 5.2%) or leg lean mass (M = 3.7 ± 4.2, W = 2.7 ± 2.8%). There were no fiber-type transformations, and the decreases in type I (M = 4.8 ± 5.0, W = 5.9 ± 3.4%), IIa (M = 7.9 ± 9.9, W = 8.8 ± 8.0%), and IIx (M = 10.7 ± 10.8, W = 10.8 ± 12.1%) fiber areas were similar between sexes. These findings indicate that immobilization-induced loss of knee extensor muscle strength is greater in women compared with men despite a similar extent of atrophy at the myofiber and whole muscle levels after 14 days of unilateral leg immobilization. Furthermore, we have described an effective and safe knee immobilization method that results in reductions in quadriceps muscle strength and size.

scholarly journals Genetic and environmental influences on skeletal muscle phenotypes as a function of age and sex in large, multigenerational families of African heritage

2007 ◽  
Vol 103 (4) ◽  
pp. 1121-1127 ◽  
Author(s):  
Steven J. Prior ◽  
Stephen M. Roth ◽  
Xiaojing Wang ◽  
Candace Kammerer ◽  
Iva Miljkovic-Gacic ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Lean Mass ◽  
Genetic Correlations ◽  
Cross Sectional Area ◽  
Calf Muscle ◽  
Sectional Area ◽  
Cross Sectional ◽  
African Heritage ◽  
Genetic Components ◽  
Muscle Cross Sectional Area

The aim of this study was to estimate the heritability of and environmental contributions to skeletal muscle phenotypes (appendicular lean mass and calf muscle cross-sectional area) in subjects of African descent and to determine whether heritability estimates are impacted by sex or age. Body composition was measured by dual-energy X-ray absorptiometry and computed tomography in 444 men and women aged 18 yr and older (mean: 43 yr) from eight large, multigenerational Afro-Caribbean families (family size range: 21–112). Using quantitative genetic methods, we estimated heritability and the association of anthropometric, lifestyle, and medical variables with skeletal muscle phenotypes. In the overall group, we estimated the heritability of lean mass and calf muscle cross-sectional area (h2 = 0.18–0.23, P < 0.01) and contribution of environmental factors to these phenotypes ( r2 = 0.27–0.55, P < 0.05). In our age-specific analysis, the heritability of leg lean mass was lower in older vs. younger individuals (h2 = 0.05 vs. 0.23, respectively, P = 0.1). Sex was a significant covariate in our models ( P < 0.001), although sex-specific differences in heritability varied depending on the lean mass phenotype analyzed. High genetic correlations (ρG = 0.69–0.81; P < 0.01) between different lean mass measures suggest these traits share a large proportion of genetic components. Our results demonstrate the heritability of skeletal muscle traits in individuals of African heritage and that heritability may differ as a function of sex and age. As the loss of skeletal muscle mass is related to metabolic abnormalities, disability, and mortality in older individuals, further research is warranted to identify specific genetic loci that contribute to these traits in general and in a sex- and age-specific manner.

Effects of Blood Flow Restriction Combined With Resistance Training or Neuromuscular Electrostimulation on Muscle Cross-Sectional Area

2021 ◽  
pp. 1-6
Author(s):  
João Guilherme Almeida Bergamasco ◽  
Ieda Fernanda Alvarez ◽  
Thais Marina Pires de Campos Biazon ◽  
Carlos Ugrinowitsch ◽  
Cleiton Augusto Libardi
Keyword(s):  
Blood Flow ◽  
Resistance Training ◽  
Muscle Hypertrophy ◽  
Vastus Lateralis ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Flow Restriction ◽  
Neuromuscular Electrostimulation ◽  
Muscle Cross Sectional Area

Context: Low-load resistance training (LL) and neuromuscular electrostimulation (NES), both combined with blood flow restriction (BFR), emerge as effective strategies to maintain or increase muscle mass. It is well established that LL-BFR promotes similar increases in muscle cross-sectional area (CSA) and lower rating of perceived exertion (RPE) and pain compared with traditional resistance training protocols. On the other hand, only 2 studies with conflicting results have investigated the effects of NES-BFR on CSA, RPE, and pain. In addition, no study directly compared LL-BFR and NES-BFR. Objective: The aim of the study was to compare the effects of LL-BFR and NES-BFR on vastus lateralis CSA, RPE, and pain. Individual response for muscle hypertrophy was also compared between protocols. Design: Intrasubject longitudinal study. Setting: University research laboratory. Intervention: Fifteen healthy young males (age = 23 [5] y; weight = 77.6 [11.3] kg; height = 1.76 [0.08] m). Main Outcome Measures: Vastus lateralis CSA was measured through ultrasound at baseline (pre) and after 20 training sessions (post). The RPE and pain responses were obtained through modified 10-point scales, handled during all training sessions. Results: Both protocols demonstrated significant increases in muscle CSA (P < .0001). However, the LL-BFR demonstrated significantly greater CSA changes compared with NES-BFR (LL-BFR = 11.2%, NES-BFR = 4.6%; P < .0001). Comparing individual increases in CSA, 12 subjects (85.7% of the sample) presented greater muscle hypertrophy for LL-BFR than for the NES-BFR protocol. In addition, LL-BFR produced significantly lower RPE and pain responses (P < .0001). Conclusions: The LL-BFR produced significantly greater increases in CSA with significant less RPE and pain than NES-BFR. In addition, LL-BFR resulted in greater individual muscle hypertrophy responses for most subjects compared with NES-BFR.

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