ISSN:
1439-6327
Keywords:
Human
;
Endurance exercise
;
Muscles
;
Fibre types
;
Histocytochemistry
;
Ultrastructure
;
Morphometry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The main fibre types ofM. vastus lateralis of 10 trained or untrained male individuals (25–35 years) were quantitatively determined by morphological techniques; the fibre types being defined according to the M-band appearance. The volume density of mitochondria (Vmit) was higher in endurance-trained muscles.Vmit was higher in Type 1 than in Type 2 fibres, there being no difference between subtypes of Type 2 fibres. The volume density of lipid droplets (Vli) showed a wide range of values both with respect to degree of training and between fibre types. Z-band width was not influenced by endurance training, but was considerably larger in Type 1 than in Type 2 fibres. Discriminant analysis showed that 46% of the fibres, preclassified according to the M-band appearance, would have been correctly allocated on basis of theVmit. The corresponding value for lipid droplets was 42% and for the Z-band width, 62%. It is concluded thatVmit is not a satisfactory criterion for discriminating between fibre types, especially between Type 2A and Type 2B in trained subjects. The study also shows that endurance training reduces the relative importance of individual-dependent factors in comparison with muscle fibre properties when concerningVmit.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01015207
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