The potential for fiber-type composition adaptation in athletes in response to training represents one of the most pressing issues in sports science. The purpose of the study is an analytical review of documentary sources on the potential for changes in skeletal muscle fiber-type composition in athletes in response to training. Research methods: analysis of scientific publications in the PubMed, Medline, and Google Scholar databases. Research results and conclusions. The classification of muscle fibers based on the assessment of myosin ATPase activity indicates that strength training does not change the ratio of type I to type II muscle fibers, but it increases the percentage of type IIA fibers. Analysis of single fibers using SDS-PAGE does not provide a clear answer regarding fiber-type transformation in response to resistance training. Studies on the effects of training on endurance and fiber-type composition, based on the assessment of myosin ATPase activity, are contradictory. Some data support a genetic predisposition in the ratio of type I to type II fibers, while others suggest the possibility of changes. Analysis of single fibers via SDS-PAGE reveals that fiber-type composition may shift toward an increased proportion of slow-twitch MHCI fibers, primarily through a reduction in hybrid muscle fibers.
Samsonova et al. (Wed,) studied this question.