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

2000 ◽  
Vol 3 (4) ◽  
pp. 217-218
Keyword(s):  
Resistance Training ◽  
Muscle Fiber ◽  
Contractile Function ◽  
Older Men ◽  
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.

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

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

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

Reduction in single muscle fiber rate of force development with aging is not attenuated in world class older masters athletes

2016 ◽  
Vol 310 (4) ◽  
pp. C318-C327 ◽  
Author(s):  
Geoffrey A. Power ◽  
Fábio C. Minozzo ◽  
Sally Spendiff ◽  
Marie-Eve Filion ◽  
Yana Konokhova ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Contractile Function ◽  
Vastus Lateralis ◽  
Cellular Aging ◽  
Single Muscle ◽  
Single Muscle Fiber ◽  
Cross Bridge ◽  
Masters Athletes ◽  
Slow Type ◽  
World Class

Normal adult aging is associated with impaired muscle contractile function; however, to what extent cross-bridge kinetics are altered in aging muscle is not clear. We used a slacken restretch maneuver on single muscle fiber segments biopsied from the vastus lateralis of young adults (∼23 yr), older nonathlete (NA) adults (∼80 yr), and age-matched world class masters athletes (MA; ∼80 yr) to assess the rate of force redevelopment ( ktr) and cross-bridge kinetics. A post hoc analysis was performed, and only the mechanical properties of “slow type” fibers based on unloaded shortening velocity ( Vo) measurements are reported. The MA and NA were ∼54 and 43% weaker, respectively, for specific force compared with young. Similarly, when force was normalized to cross-sectional area determined via the fiber shape angularity data, both old groups did not differ, and the MA and NA were ∼43 and 48% weaker, respectively, compared with young ( P < 0.05). Vo for both MA and NA old groups was 62 and 46% slower, respectively, compared with young. Both MA and NA adults had approximately two times slower values for ktr compared with young. The slower Vo in both old groups relative to young, coupled with a similarly reduced ktr, suggests impaired cross-bridge kinetics are responsible for impaired single fiber contractile properties with aging. These results challenge the widely accepted resilience of slow type fibers to cellular aging.

Resistance training improves single muscle fiber contractile function in older women

2001 ◽  
Vol 281 (2) ◽  
pp. C398-C406 ◽  
Author(s):  
Scott Trappe ◽  
Michael Godard ◽  
Philip Gallagher ◽  
Chad Carroll ◽  
Greg Rowden ◽  
...  
Keyword(s):  
Resistance Training ◽  
Single Cell ◽  
Older Women ◽  
Muscle Fiber ◽  
Peak Power ◽  
Older Men ◽  
Single Muscle ◽  
Mhc I ◽  
Before And After ◽  
Mhc Iia

The purpose of this study was to 1) examine single cell contractile mechanics of skeletal muscle before and after 12 wk of progressive resistance training (PRT) in older women ( n = 7; 74 ± 2 yr) and 2) to compare these results to our previously completed single cell PRT work with older men ( n = 7; 74 ± 2 yr) (Trappe S, Williamson D, Godard M, Porter D, Rowden G, and Costill D. J Applied Physiol 89:143–152, 2000). Knee extensor PRT was performed 3 days/wk at 80% of one-repetition maximum. Muscle biopsies were obtained from the vastus lateralis before and after the PRT. Chemically skinned single muscle fibers ( n = 313) were studied at 15°C for peak tension (Po), unloaded shortening velocity ( V o), and power. Due to the low number of hybrid fibers identified post-PRT, direct comparisons were limited to MHC I and IIa fibers. Muscle fiber diameter increased 24% (90 ± 2 to 112 ± 6 μm; P < 0.05) in MHC I fibers with no change in MHC IIa fibers. Po increased ( P< 0.05) 33% in MHC I (0.76 ± 0.04 to 1.01 ± 0.09 mN) and 14% in MHC IIa (0.73 ± 0.04 to 0.83 ± 0.05 mN) fibers. Muscle fiber V o was unaltered in both fiber types with PRT. MHC I and IIa fiber power increased ( P< 0.05) 50% [11 ± 2 to 17 ± 2 μN · fiber length (FL) · s−1] and 25% (40 ± 8 to 51 ± 6 μN · FL · s−1), respectively. However, when peak power was normalized to cell size, no pre- to postimprovements were observed. These data indicate that PRT in elderly women increases muscle cell size, strength, and peak power in both slow and fast muscle fibers, which was similar to the older men. However, in contrast to the older men, no change in fiber V o or normalized power was observed in the older women. These data suggest that older men and women respond differently at the muscle cell level to the same resistance-training stimulus.

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