Background: A sedentary lifestyle is associated with cardiometabolic risk factors and obesity. This study aims to investigate the effects of regular exercise training, acute exercise, and a sedentary lifestyle on levels of miRNA-33, miRNA-335, miRNA-370, miRNA-758, which play a regulatory role in lipid metabolism and contribute to the elucidation of the molecular mechanisms involved in the exercise.

Methods: The study included 30 elite taekwondo female athletes and 30 sedentary women who didn’t exercise regularly. Plasma miRNA-33, miRNA-335, miRNA-370, miRNA-758 levels were evaluated by using real-time quantitative PCR (RT-PCR) analysis. The levels of selected biochemical parameters were measured by a colorimetric method with an automated Architect C 8000 System (Abbott Laboratories, Abbott Park, IL, USA).

Results: Plasma miRNA-33 levels were found to be significantly higher in the pre-exercise [5.96 (1.48- 23.92), p<0.001] and post-exercise groups [6.82 (0.72-96.34), p<0.001] compared to the sedentary group [2.67 (0.12-8.88)]. miRNA-758 levels were lower in the post-exercise [0.0016 (0.0010-0.02)] group compared to the pre-exercise [0.0099 (0.0009-0.04), p<0.001] and sedentary groups [0.0123 (0.0011-0.04), p<0.001]. miRNA-370 levels were lower in the pre-exercise [3.11 (0.70-17.15)] group compared to the post-exercise [7.41 (2.81-56.89), p<0.001] and sedentary [8.17 (0.32-26.35), p<0.001] groups. There was no statistically significant difference between miRNA-335 levels (p>0.05).

Conclusions: Our findings suggest that regular exercise has a significant impact on lipid metabolism at the molecular level and miRNA-33, miRNA-370 and miRNA-758 play a key role in regulating the metabolic response to exercise.