Effects of HIIT Intervention on PGC-1α and AdipoR1 Genes Expressions and Body Composition in Obese Individuals

Introduction : Lifestyle-related diseases are rapidly increasing, in part due to less physical activity. The health beneficial effects of regular physical activity include metabolic adaptations in skeletal muscle, which contributes greatly to improved overall metabolism. However, little is known about the effect of high-intensity interval training (HIIT) on the expression of key regulatory proteins that are linked to fatty acid oxidation and insulin sensitivity in obese individuals. This study investigated the effects of 12-week HIIT on the expression of PGC-1α and AdipoR1 and body composition in overweigh/obese individuals. Method : Fifty individuals were randomly assigned to either a control (n=25) or HIIT (n=25) group. Subjects assigned to HIIT underwent a 12-week HIIT intervention 3 days/week at an intensity of 65%-80% of the age-based maximum heart rate. Anthropometric measurements and gene expression analysis were conducted at baseline and post intervention. Data were analysed using mixed-designed ANOVA. Results: Significant time-by-group interactions (p<0.001) were found for weight, BMI, waist circumference and percentage of body fat. The HIIT group had significantly lower weight (-2.3%, p<0.001), BMI (-2.7%, p<0.001), waist circumference (-2.4%, p<0.001) and percentage of body fat (-4.3%, p<0.001) post intervention. HIIT also significantly increased the expression of PGC-1α and AdipoR1 by 2-fold and 3-fold respectively. Conclusion: Findings from current study suggest that HIIT modulates the PGC-1α and AdipoR1 gene expressions, in conjuction with modest improvements in body composition in overweight/obese individuals. This implies that manipulation of the expression of these genes could be a potential surrogate for exercise-mediated improvements of improved metabolism in overweight/obese individuals.