Introduction: microRNAare a new class of biological indicators that are involved in the structural and functional changes of the heart at the cellular level and signaling pathway. The aim of the present study was to compare a period of intense intermittent exercise with continuous endurance on the expression of mir-1 gene in cardiomyocytes of male rats. Method: For this purpose, 14 male rats were randomly divided into two control and experimental groups after familiarization with the training protocol. The experimental group performed a program (12 weeks) of aerobic exercises on a treadmill. In the following 48 hours after the end of the last training session, they were anesthetized and dissected, then their hearts and left ventricles were removed and the expression level of -1 miR in their hearts was measured using real-time PCR method. Results: The result of the study showed that the mir-1 expression of the training group was significantly lower than the control group. Conclusion: In fact can said that Aerobic exercises increase heart efficiency by reducing Mir-1 expression.
