Circulating microRNAs in response to exercise.

MicroRNAs (miRNAs, miRs) are a novel class of endogenous noncoding RNAs, which post-transcriptionally regulate gene expression via mRNA degradation or translational inhibition. miRNAs have become increasingly recognized as central players in the process of gene regulation and are responsible for a variety of essential biological processes including proliferation, differentiation and metabolism. miRNAs can be released into the circulation where they remain stable. Exercise is one of the most positive and effective means of achieving enhanced physique. This review highlights and summarizes recent progress in the field of circulating miRNAs in response to acute and chronic exercise and discusses future directions in studying circulating miRNAs in exercise-induced adaptation. A better understanding of how circulating miRNAs participate in the physiological response to exercise would eventually help develop circulating miRNAs as therapeutic targets for improving exercise capacity in patients with heart failure and other diseases.