The impact of aerobic training intensity on skeletal muscle PGC-1α, interferon regulatory factor 4, and atherogenic index in obese male Wistar rats

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) is the main regulator in energy metabolism. Training stimulates many processes like mitochondrial biogenesis, glucose metabolism, and fatty acids metabolism. It also increases the capacity of fat oxidation. The purpose of this study was to investigate the effects of eight-week aerobic training of different intensities on PGC-1α, interferon regulatory factor 4 (IRF4), and atherogenic index in obese male Wistar rats. Twenty-four obese male rats induced by a high-fat diet (weight: 250 to 300 gr, BMI >30g/cm2) were divided into three groups: aerobic training of moderate intensity (MI), aerobic training of high intensity (HI), and the control group (C). The MI and HI training groups carried out exercise training by eight weeks of walking on a treadmill for five sessions/week, 60 min per session, and at a speed of 28 m/min and 34 m/min, respectively. The levels of PGC-1a in the MI and HI groups significantly increased compared to the C group (p < 0.05). Moreover, there was no significant differences between IRF4 levels of MI and HI groups (p > 0.05). The serum HDL-C levels increased only in the MI group compared to the C group (p  < 0.05). The LDL-C, TG, TC, and atherogenic index levels reduced more significantly in MI and HI groups than in the C group (p  < 0.05). The results show that eight-week aerobic training of two moderate and high intensities may be the signaling pathways to the activation of the PGC-1a protein (i.e., a key regulator of energy metabolism and mitochondrial biogenesis) in skeletal muscle.