The Effect of 12 Weeks of Concurrent Training (Aerobic and Strength) on the Levels of miR-155 and C-reactive Protein in Obese Middle-Aged Men

Background: Some micro RNAs (miRNA) are secreted by adipose tissue and play a role in intercellular communication and are considered as a valuable target point in order to control obesity and its consequences. The aim of the present study is to determine the effect of two concurrent aerobic and strength training methods on the levels of miR-155 and C-reactive protein (CRP) in obese middle-aged men. Methods: Thirty middle-aged men with an average age of 44.57 ± 3.54 years and weight 103.79 ± 8.46 kg, randomly and based on fat percentage, aerobic capacity (V̇O2max) and one repetition maximum (1-RM) were assigned to three groups: 1) concurrent aerobic and strength training in one day (CAST1), 2) concurrent aerobic and strength training on separate days (CAST2) and 3) control group. Blood samples were collected from the subjects 48 hours before and after 12 weeks of concurrent training, in order to analyse of miR-155, CRP and glucose indices. One-way ANOVA with repeated measures and Bonferroni's post hoc test were used to analyze the data. Findings: After 12 weeks of training, CAST1 group experienced a significant decrease in miR-155, CRP and glucose indices compared to the control group. Also, in the CAST2 group, miR-155, CRP and glucose indices were significantly decreased compared to the control group. Conclusion: It seems that both CAST training methods reduce obesity-related inflammation by affecting miR-155, and middle-aged men may be able to use both training methods to prevent metabolic diseases.