Changes in skeletal muscle in males and females following endurance training

2001 ◽  
Vol 79 (5) ◽  
pp. 386-392 ◽  
Author(s):  
S L Carter ◽  
C D Rennie ◽  
S J Hamilton ◽  
M A Tarnopolsky

Gender differences in substrate selection have been reported during endurance exercise. To date, no studies have looked at muscle enzyme adaptations following endurance exercise training in both genders. We investigated the effect of a 7-week endurance exercise training program on the activity of β-oxidation, tricarboxylic acid cycle and electron transport chain enzymes, and fiber type distribution in males and females. Training resulted in an increase in [Formula: see text]O2peak for both males and females of 17% and 22%, respectively (P < 0.001). The following muscle enzyme activities increased similarly in both genders: 3-β-hydroxyacyl CoA dehydrogenase (38%), citrate synthase (41%), succinate-cytochrome c oxidoreductase (41%), and cytochrome c oxidase (COX; 26%). The increase in COX activity was correlated (R2 = 0.52, P < 0.05) with the increase in [Formula: see text]O2peak/ fat free mass. Fiber area, size, and % area were not affected by training for either gender, however, males had larger Type II fibers (P < 0.05) and females had a greater Type I fiber % area (P < 0.05). Endurance training resulted in similar increases in skeletal muscle oxidative potential for both males and females. Training did not affect fiber type distribution or size in either gender.Key words: endurance training, oxidative potential, gender.

2016 ◽  
Vol 35 (6) ◽  
pp. 1359-1365 ◽  
Author(s):  
Michael J. Toth ◽  
Damien M. Callahan ◽  
Mark S. Miller ◽  
Timothy W. Tourville ◽  
Sarah B. Hackett ◽  
...  

2000 ◽  
Vol 279 (4) ◽  
pp. E744-E751 ◽  
Author(s):  
Agneta Andersson ◽  
Anders Sjödin ◽  
Anu Hedman ◽  
Roger Olsson ◽  
Bengt Vessby

Endurance trained ( n = 14) and untrained young men ( n = 15) were compared regarding the fatty acid profile of the vastus lateralis muscle after 8 wk on diets with a similar fatty acid composition. The skeletal muscle phospholipids in the trained group contained lower proportions of palmitic acid (16:0) (−12.4%, P < 0.001) and di-homo-γ-linolenic acid [20:3(n-6)] (−15.3%, P = 0.018), a lower n-6-to-n-3 ratio (−42.0%, P = 0.015), higher proportions of stearic acid (18:0) (+9.8%, P = 0.004) and sum of n-3 polyunsaturated fatty acids (+33.8%, P = 0.009), and a higher ratio between 20:4(n-6) to 20:3(n-6) (+18.4%, P = 0.006) compared with those in the untrained group. The group differences in 16:0, 20:3(n-6), 18:0/16:0, and 20:4(n-6)/20:3(n-6) were independent of fiber-type distribution. The trained group also showed a lower proportion of 16:0 (−7.9%, P < 0.001) in skeletal muscle triglycerides irrespective of fiber type. In conclusion, the fatty acid profile of the skeletal muscle differed between trained and untrained individuals, although the dietary fatty acid composition was similar. This difference was not explained by different fiber-type distribution alone but appears to be a direct consequence of changes in fatty acid metabolism due to the higher level of physical activity.


1986 ◽  
Vol 64 (9) ◽  
pp. 1245-1251 ◽  
Author(s):  
C. Bouchard ◽  
J. A. Simoneau ◽  
G. Lortie ◽  
M. R. Boulay ◽  
M. Marcotte ◽  
...  

The purpose of the study was to estimate the genetic effect for skeletal muscle characteristics using pairs of nontwin brothers (n = 32), dizygotic (DZ) twins (n = 26), and monozygotic (MZ) twins (n = 35). They were submitted to a needle biopsy of the vastus lateralis for the determination of fiber type distribution (I, IIa, IIb) and the following enzymes were assayed for maximal activity: creatine kinase, hexokinase, phosphofructokinase (PFK), lactate dehydrogenase, malate dehydrogenase, 3-hydroxyacyl CoA dehydrogenase, and oxoglutarate dehydrogenase (OGDH). For the percentage of type I fibers, intraclass correlations were 0.33 (p < 0.05), 0.52 (p < 0.01), and 0.55 (p < 0.01) in brothers and DZ and MZ twins, respectively. MZ twins exhibited significant within-pair resemblance for all enzyme activities (0.30 ≤ r ≤ 0.68). In spite of these correlations, genetic analyses performed with the twin data alone indicated that there was no significant genetic effect for muscle fiber type I, IIa, and IIb distribution and fiber areas. Although there were significant correlations in MZ twins for all muscle enzyme activities, the often nonsignificant intraclass coefficients found in brothers and DZ twins suggest that variations in enzyme activities are highly related to common environmental conditions and nongenetic factors. However, genetic factors appear to be involved in the variation of regulatory enzymes of the glycolytic (PFK) and citric acid cycle (OGDH) pathways and in the variation of the oxidative to glycolytic activity ratio (PFK/OGDH ratio). Data show that these genetic effects reach only about 25–50% of the total phenotypic variation when data are adjusted for age and sex differences.


2021 ◽  
Author(s):  
Nikolay Oskolkov ◽  
Malgorzata Santel ◽  
Ola Ekström ◽  
Gray J. Camp ◽  
Eri Miyamoto-Mikami ◽  
...  

Abstract BACKGROUND: Skeletal muscle fiber type distribution has implications for human health, muscle function and performance. This knowledge has been gathered using labor-intensive and costly methodology that limited these studies. Here we present a method based on muscle tissue RNA sequencing data (totRNAseq) to estimate the distribution of skeletal muscle fiber types from frozen human samples, allowing for a larger number of individuals to be tested.METHODS: By using single-nuclei RNA sequencing (snRNAseq) data as a reference, cluster expression signatures were produced by averaging gene expression of cluster gene markers and then applying these to totRNAseq data and inferring muscle fiber nuclei type via linear matrix decomposition. This estimate was then compared with fiber type distribution measured by ATPase staining or myosin heavy chain protein isoform distribution of 62 muscle samples in two independent cohorts (n = 39 and 22).RESULTS: The correlation between the sequencing-based method and the other two were rATPas = 0.65 [0.46 – 0.84], [95% CI] and rmyosin = 0.80 [0.71 – 0.89], with p = 7.96 x 10-6 and 8.06 x 10-6 respectively. The deconvolution inference of fiber type composition was accurate even for very low totRNAseq sequencing depths, i.e., down to an average of ~5.000 paired-end reads.CONCLUSIONS: This new method (https://github.com/OlaHanssonLab/PredictFiberType) consequently allows for measurement of fiber type distribution of a larger number of samples using totRNAseq in a cost and labor-efficient way. For the first time, it is now feasible to study the association between fiber type distribution and e.g. health outcomes in large well-powered studies.


2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Jian Shou ◽  
Peijie Chen ◽  
Weihua Xiao

Objective Explore the relationship between exercise adaptation of skeletal muscle fibers and microRNAs. Methods Research related papers. Results endurance training can switch muscle fiber type by promoting microRNAs (miR-208b, miR-499). For example, the conversion from fast Type IIb muscle fibers to slower Type IIx/d muscle fibers, or from Type IIx muscle fibers to Type IIa muscle fibers. Endurance training can also promote the expression of Peroxisome Proliferator Receptor Gamma Coactivator-1α (PGC-1α) and enhance the oxidative potential for slow muscle fibers by inhibiting some microRNAs such as miR-23a. Resistance training can activate insulin-like growth factor-1/phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin/P70 ribosomal protein S6 kinase (IGF-1/PI3K/Akt/mTOR/P70S6K) pathways and promote fast muscle fibers hypertrophy by inhibiting negative microRNAs (miR-1,miR-133,miR-128a) and promoting positive microRNAs (miR-27,miR-29,miR-486). Conclusions MicroRNAs play an important role in the exercise adaptation of skeletal muscle fibers.


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