Muscle fibre types and enzyme activities after training with local leg ischaemia in man.
1993 (English)In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 148, no 3, 233-41 p.Article in journal (Refereed) Published
Eight healthy men performed supine one-legged training on a bicycle ergometer 45 min per leg four times per week for 4 week. The ergometer and lower body were inside a pressure chamber, the opening of which was sealed at the level of the crotch. One leg trained with impeded leg blood flow (I-leg), induced by an increased (50 mmHg) chamber pressure, at the highest tolerable intensity. The contralateral leg trained at the same power under normal pressure (N-leg). Before and after training biopsies were taken from the vastus lateralis of both legs and maximal one-legged exercise tests were executed with both legs. Biopsies were repeated when the subjects had been back to their habitual physical activity for 3 months. Training increased exercise time to exhaustion, but more in the I-leg than in the N-leg. After training, the I-leg had higher activity of citrate synthase (CS), a marker of oxidative capacity, and lower activity of the M-subunit of lactate dehydrogenase isoenzymes. It also had a higher percentage of type-I fibres and a lower percentage of IIB fibres, larger areas of all fibre types and a greater number of capillaries per fibre. It is concluded that ischaemic training changes the muscle metabolic profile in a direction facilitating aerobic metabolism. An altered fibre-type composition may contribute, but is not enough prerequisite for the change.
Place, publisher, year, edition, pages
1993. Vol. 148, no 3, 233-41 p.
capillaries, fast-twitch fibres, fibre cross-sectional areas, skeletal muscle, slow-twitch fibres
IdentifiersURN: urn:nbn:se:kth:diva-44620DOI: 10.1111/j.1748-1716.1993.tb09554.xISI: A1993LL65000001PubMedID: 8213179OAI: oai:DiVA.org:kth-44620DiVA: diva2:452038
QC 201111092011-10-272011-10-252011-11-09Bibliographically approved