scholarly journals Single muscle fiber adaptations to resistance training in old (>80 yr) men: evidence for limited skeletal muscle plasticity

2008 ◽  
Vol 295 (1) ◽  
pp. R273-R280 ◽  
Author(s):  
Dustin Slivka ◽  
Ulrika Raue ◽  
Chris Hollon ◽  
Kiril Minchev ◽  
Scott Trappe
Keyword(s):  
Resistance Training ◽  
Muscle Fiber ◽  
Single Muscle ◽  
Very Old ◽  
Repetition Maximum ◽  
Muscle Plasticity ◽  
Single Muscle Fiber ◽  
Before And After ◽  
Old Men ◽  
Whole Muscle

The purpose of this study was to investigate whole muscle and single muscle fiber adaptations in very old men in response to progressive resistance training (PRT). Six healthy independently living old men (82 ± 1 yr; range 80–86 yr, 74 ± 4 kg) resistance-trained the knee extensors (3 sets, 10 repetitions) at ∼70% one repetition maximum 3 days/wk for 12 wk. Whole thigh muscle cross-sectional area (CSA) was assessed before and after PRT using computed tomography (CT). Muscle biopsies were obtained from the vastus lateralis before and after the PRT program. Isolated myosin heavy chain (MHC) I and IIa single muscle fibers ( n = 267; 142 pre; 125 post) were studied for diameter, peak tension, shortening velocity, and power. An additional set of isolated single muscle fibers ( n = 2,215; 1,202 pre; 1,013 post) was used to identify MHC distribution. One repetition maximum knee extensor strength increased ( P < 0.05) 23 ± 4 kg (56 ± 4 to 79 ± 7 kg; 41%). Muscle CSA increased ( P < 0.05) 3 ± 1 cm2 (120 ± 7 to 123 ± 7 cm2; 2.5%). Single muscle fiber contractile function and MHC distribution were unaltered with PRT. These data indicate limited muscle plasticity at the single-muscle fiber level with a resistance-training program among the very old. The minor increases in whole muscle CSA coupled with the static nature of the myocellular profile indicate that the strength gains were primarily neurological. These data contrast typical muscle responses to resistance training in young (∼20 yr) and old (∼70 yr) humans and indicate that the physiological regulation of muscle remodeling is adversely modified in the oldest old.

Effects of Short-Term Concentric vs. Eccentric Resistance Training on Single Muscle Fiber MHC Distribution in Humans

2005 ◽  
Vol 26 (5) ◽  
pp. 339-343 ◽  
Author(s):  
U. Raue ◽  
B. Terpstra ◽  
D. L. Williamson ◽  
P. M. Gallagher ◽  
S. W. Trappe
Keyword(s):  
Resistance Training ◽  
Muscle Fiber ◽  
Single Muscle ◽  
Short Term ◽  
Single Muscle Fiber

scholarly journals Contractile Properties of Single Muscle Fiber and Their Relations to Whole Muscle Strength in Korean Young Male

2018 ◽  
Vol 27 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Yu-Nah Jeon ◽  
Hee-Jaeng Kim ◽  
So-Young Yang ◽  
So-Hyun Lee ◽  
Dae-Young Kim ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Muscle Fiber ◽  
Young Male ◽  
Contractile Properties ◽  
Single Muscle ◽  
Single Muscle Fiber ◽  
Whole Muscle

Single Muscle Fiber Adaptations to Resistance training in the Oldest-Old Women

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S276
Author(s):  
Dustin Slivka ◽  
Ulrika Raue ◽  
Kiril Minchev ◽  
Scott Trappe
Keyword(s):  
Resistance Training ◽  
Muscle Fiber ◽  
Oldest Old ◽  
Single Muscle ◽  
Single Muscle Fiber

Effect of resistance training on single muscle fiber contractile function in older men

2000 ◽  
Vol 89 (1) ◽  
pp. 143-152 ◽  
Author(s):  
Scott Trappe ◽  
David Williamson ◽  
Michael Godard ◽  
David Porter ◽  
Greg Rowden ◽  
...  
Keyword(s):  
Resistance Training ◽  
Muscle Fiber ◽  
Contractile Function ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Older Men ◽  
Single Muscle ◽  
Mhc I ◽  
Before And After ◽  
Mhc Iia

The purpose of this study was to examine single cell contractile mechanics of skeletal muscle before and after 12 wk of progressive resistance training (PRT) in older men ( n = 7; age = 74 ± 2 yr and weight = 75 ± 5 kg). Knee extensor PRT was performed 3 days/wk at 80% of one-repetition maximum. Muscle biopsy samples were obtained from the vastus lateralis before and after PRT (pre- and post-PRT, respectively). For analysis, chemically skinned single muscle fibers were studied at 15°C for peak tension [the maximal isometric force (Po)], unloaded shortening velocity ( V o), and force-velocity parameters. In this study, a total of 199 (89 pre- and 110 post-PRT) myosin heavy chain (MHC) I and 99 (55 pre- and 44 post-PRT) MHC IIa fibers were reported. Because of the minimal number of hybrid fibers identified post-PRT, direct comparisons were limited to MHC I and IIa fibers. Muscle fiber diameter increased 20% (83 ± 1 to 100 ± 1 μm) and 13% (86 ± 1 to 97 ± 2 μm) in MHC I and IIa fibers, respectively ( P < 0.05). Po was higher ( P < 0.05) in MHC I (0.58 ± 0.02 to 0.90 ± 0.02 mN) and IIa (0.68 ± 0.02 to 0.85 ± 0.03 mN) fibers. Muscle fiber V o was elevated 75% (MHC I) and 45% (MHC IIa) after PRT ( P < 0.05). MHC I and IIa fiber power increased ( P < 0.05) from 7.7 ± 0.5 to 17.6 ± 0.9 μN · fiber lengths · s−1 and from 25.5 to 41.1 μN · fiber lengths · s−1, respectively. These data indicate that PRT in elderly men increases muscle cell size, strength, contractile velocity, and power in both slow- and fast-twitch muscle fibers. However, it appears that these changes are more pronounced in the MHC I muscle fibers.

scholarly journals Single muscle fiber gene expression with resistance training in young women

2008 ◽  
Vol 22 (S1) ◽  
Author(s):  
Ulrika Raue ◽  
Travis Conley ◽  
Emily Louis ◽  
Kiril Minchev ◽  
Bozena Jemiolo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Resistance Training ◽  
Young Women ◽  
Muscle Fiber ◽  
Single Muscle ◽  
Single Muscle Fiber ◽  
Fiber Gene

scholarly journals Reduction in hybrid single muscle fiber proportions with resistance training in humans

2001 ◽  
Vol 91 (5) ◽  
pp. 1955-1961 ◽  
Author(s):  
D. L. Williamson ◽  
P. M. Gallagher ◽  
C. C. Carroll ◽  
U. Raue ◽  
S. W. Trappe
Keyword(s):  
Resistance Training ◽  
Muscle Fiber ◽  
Vastus Lateralis ◽  
Electrophoretic Analysis ◽  
Training Data ◽  
Single Muscle ◽  
Hybrid Fibers ◽  
Mhc I ◽  
Single Muscle Fiber ◽  
Mhc Iia

The purpose of this investigation was to examine the effects of 12 wk of progressive resistance training (PRT) on single muscle fiber myosin heavy chain (MHC; I, I/IIa, I/IIa/IIx, IIa, IIa/IIx, IIx) isoform proportions in young individuals. Young, untrained men (YM; n = 6) and women (YW; n = 6) (age = 22 ± 1 and 25 ± 2 yr for YW and YM, respectively) received pre- and post-PRT muscle biopsies from the right vastus lateralis for single muscle fiber MHC distribution by electrophoretic analysis (192 ± 5 pre- and 183 ± 6 post-fibers/subject analyzed; 4,495 fibers total). Data are presented as percentages of the total fibers analyzed per subject. The PRT protocol elicited an increase in the pure MHC IIa (Δ = + 24 and + 27; YW and YM, respectively; P < 0.05) with no change in the pure MHC I distribution. The hybrid MHC distributions decreased I/IIa/IIx (Δ = −2; YM and YW; P < 0.05), IIa/IIx (Δ = −13 and −19 for YM and YW, respectively; P < 0.05), and total hybrid fiber proportion (I/IIa + I/IIa/IIx + IIa/IIx) decreased (Δ = −19 and −30 for YM and YW, respectively; P < 0.05) with the training, as did the MHC IIx distribution (Δ = −2; YW only; P < 0.05). Alterations in the predominance of MHC isoforms within hybrid fibers (decrease in MHC I-dominant I/IIa and nondominant MHC IIa/IIx, increase in MHC IIa-dominant IIa/IIx; P < 0.05) appeared to contribute to the increase in the MHC IIa proportion. Electrophoresis of muscle cross sections revealed an ∼7% increase ( P< 0.05) in MHC IIa proportion in both groups, whereas the MHC IIx decrease by 7.5 and 11.6% post-PRT in YW and YM, respectively. MHC I proportions increase in YM by 4.8% ( P < 0.05) post-PRT. These findings further support previous resistance training data in young adults with respect to the increase in the MHC IIa proportions but demonstrate that a majority of the change can be attributed to the decrease in single-fiber hybrid proportions.

EFFECTS OF CONCENTRIC VS. ECCENTRIC RESISTANCE TRAINING ON SINGLE MUSCLE FIBER MHC DISTRIBUTION IN YOUNG MEN

2002 ◽  
Vol 34 (5) ◽  
pp. S121
Author(s):  
U Raue ◽  
B Terpstra ◽  
D L. Williamson ◽  
P M. Gallagher ◽  
S W. Trappe
Keyword(s):  
Resistance Training ◽  
Muscle Fiber ◽  
Young Men ◽  
Single Muscle ◽  
Single Muscle Fiber

scholarly journals Muscle fiber size and function in elderly humans: a longitudinal study

2008 ◽  
Vol 105 (2) ◽  
pp. 637-642 ◽  
Author(s):  
Walter R. Frontera ◽  
Kieran F. Reid ◽  
Edward M. Phillips ◽  
Lisa S. Krivickas ◽  
Virginia A. Hughes ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Muscle Strength ◽  
Muscle Fiber ◽  
Type I ◽  
Single Muscle ◽  
Cross Sectional ◽  
Single Muscle Fiber ◽  
Fiber Size ◽  
Whole Muscle

Cross-sectional studies are likely to underestimate age-related changes in skeletal muscle strength and mass. The purpose of this longitudinal study was to assess whole muscle and single muscle fiber alterations in the same cohort of 12 older (mean age: start of study 71.1 ± 5.4 yr and end of study 80 ± 5.3 yr) volunteers (5 men) evaluated 8.9 yr apart. No significant changes were noted at follow-up in body weight, body mass index, and physical activity. Muscle strength, evaluated using isokinetic dynamometry, and whole muscle specific force of the knee extensors were significantly lower at follow-up. This was accompanied by a significant reduction (5.7%) in cross-sectional area of the total anterior muscle compartment of the thigh as evaluated by computed tomography. Muscle histochemistry showed no significant changes in fiber type distribution or fiber area. Experiments with chemically skinned single muscle fibers ( n = 411) demonstrated no change in type I fiber size but an increase in IIA fiber diameter. A trend toward an increase in maximal force in both fiber types was observed. Maximum unloaded shortening velocity did not change. In conclusion, single muscle fiber contractile function may be preserved in older humans in the presence of significant alterations at the whole muscle level. This suggests that surviving fibers compensate to partially correct muscle size deficits in an attempt to maintain optimal force-generating capacity.

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