Stiffness changes and fibre type transitions in rat soleus muscle produced by jumping training.
Rat soleus muscles were overloaded with intent to induce a relative increase in fast fibres and modifications in muscular stiffness. The overloading technique was a training period consisting of an 11-week vertical jump programme. The method of controlled releases was used to obtain tension/extension curves characterizing the elastic behaviour of the soleus. Fibre typing was made by myofibrillar adenosine 5'-triphosphatase staining. With regard to a control group, training resulted in a relative decrease in type I fibres for the benefit of type II fibres. Training also induced a decrease in muscle stiffness as attested notably by significant differences in maximal extension. These results are interpreted in terms of modifications occurring in the active fraction of the so-called series elastic component.
Pousson
M
M
Département de Génie Biologique, URA CNRS 858, Université de Technologie, Compiègne, France.
Pérot
C
C
Goubel
F
F
D000818:Animals; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D009132:Muscles / Q000033:anatomy & histology / Q000502:physiology*; D010805:Physical Conditioning, Animal; D051381:Rats; D011919:Rats, Inbred Strains