Comparison of the effects of eight weeks of high intensity interval training and low intensity endurance training on expression of Hig2 and intrahepatic Lipid content in rats with non-alcoholic fatty liver diseases

Non-alcoholic fatty liver disease is a major liver disease that is associated with malnutrition and overweight habits. The purpose of this study was to compare the effects of eight weeks of high intensity interval training (HIIT) and low intensity endurance training (LIET) on expression of Hig2 and intrahepatic Lipid content (IHL) in rats with non-alcoholic fatty liver diseases (NAFLD). Forty Wistar rats were randomly divided into four groups. The control, HIIT and LIRT groups that consumed high-fat foods to create fatty liver, and the scheme group that used a normal diet, for 16 weeks. The protocol of HIIT group consisted of intensity running which was separated with light running and the protocol of LIET group was matched with the whole passing distance of HIIT group with lower intensity. After 8 weeks, the expression of Hig2 and IHL level was measured. The data showed that there is a significant difference between groups in the expression of Hig2 (K2 =12/43, P=0.006) and IHL (K2 =32.84, 0.001) was observed. Significant differences in gene expression of Hig2 between control group and HIIT group (P=0.031) and control group with LIET group (P= 0.012) was observed. There was no significant difference in Hig2 expression between HIIT group and ET group (P=0.453). There was a significant difference in the content of IHL in different groups (K2 = 2.84, P=0.001). There were significant differences in IHL between the control group and the HIIT group (P= 0.001), and control group with LIET group was observed (P=0.001). The results showed that both HIIT and LIET reduce the content of liver fat and improve NAFLD through the reducing the expression of Hig2 gene. Decreasing the fatty liver in HIIT group occurs independently of weight loss.