کیوان حجازی - Department of Sport Sciences, Faculty of Sport Sciences, Hakim Sabzevari University, Sabzevar, Iran.
محمد مسافری ضیاالدینی - Department of Sport Sciences, Faculty of Physical Education and Sport Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.
سید رضا عطارزاد ه حسینی - Department of exercise physiology, Faculty of Sport Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
مهرداد فتحی - Department of exercise physiology, Faculty of Sport Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.

Peroxisome proliferator-activated receptor gamma coactivator ۱-alpha (PGC-۱α) 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-۱α, interferon regulatory factor ۴ (IRF۴), and atherogenic index in obese male Wistar rats. Twenty-four obese male rats induced by a high-fat diet (weight: ۲۵۰ to ۳۰۰ gr, BMI >۳۰g/cm۲) 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, ۶۰ min per session, and at a speed of ۲۸ m/min and ۳۴ m/min, respectively. The levels of PGC-۱a in the MI and HI groups significantly increased compared to the C group (p < ۰.۰۵). Moreover, there was no significant differences between IRF۴ levels of MI and HI groups (p > ۰.۰۵). The serum HDL-C levels increased only in the MI group compared to the C group (p  < ۰.۰۵). The LDL-C, TG, TC, and atherogenic index levels reduced more significantly in MI and HI groups than in the C group (p  < ۰.۰۵). 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-۱a protein (i.e., a key regulator of energy metabolism and mitochondrial biogenesis) in skeletal muscle.

Aerobic training, PGC-۱α, IRF۴, atherogenic index