Objective To study the influence of acute exercise on rat myocardial microRNA-30a and autophagyrelatedgene expression, and investigate the possible mechanism through which microRNA-30a regulates myocardial autophagyduring different recovery periods after exercise. Methods SD rats were randomly divided into a control group (Con), a 0 hafter exercise group (E0), a 3 h after exercise group (E3), and a 12 h after exercise group (E12). Real-time fluorescencequantitative polymerase chain reaction was used to detect the expression of ACE mRNA, microRNA-30a, Beclin-1 mRNA,and LC3 mRNA in the left ventricular myocardium. Results Compared with the control group, in the E0 group, ACE mRNAand microRNA-30a gene expression in the left ventricular muscle was significantly increased ( P <0. 05), and Beclin-1 mRNAand LC3 mRNA expression also significantly increased ( P <0. 05). This was recovered to resting state approximately 3 h afterexercise. Conclusions Acute exercise can significantly improve myocardial ACE mRNA, microRNA-30a, Beclin-1 mRNA and LC3 mRNA expression. This transient increase may be caused by exercise-induced stress.