The Role of miRNAs and Extracellular Vesicles in Adaptation After Resistance Exercise: A Review.

Resistance exercise can enhance or preserve muscle mass and/or strength. Modifying factors are secreted following resistance exercise. Biomarkers like cytokines and extracellular vesicles, especially small extracellular vesicles, are released into the circulation and play an important role in cell-to-cell and inter-tissue communications. There is increasing evidence that physical activity itself promotes the release of extracellular vesicles into the bloodstream, suggesting the importance of vesicles in mediating systemic adaptations following exercise. Extracellular vesicles contain proteins, nucleic acids like miRNAs, and other molecules targeting different cell types and tissues of distant organs. Therefore, extracellular vesicles and encapsulated miRNAs are fine tuners of protein synthesis and are important in the adaptation after resistance training. However, there is a lack of strong data supporting the precise mechanisms of these processes. In this literature review, we collected publications related to miRNA and extracellular vesicle profile changes induced by resistance exercise. To the best of our knowledge, the changes in human extracellular vesicle and microRNA profiles following resistance exercise have not been reviewed yet. We aimed to assess the shortcomings and difficulties characterizing this research area, to summarize the existing results to date, and to propose possible solutions that could help standardize the implementation of future investigations.