comparative effects of moderate intensity continuous training and high intensity interval training on serum levels of myonectin in rats

Background: myonectin (ctrp15), a recently identified myokine, plays a crucial role in regulating glucose metabolism.objectives: this study aimed to compare the effects of high-intensity interval training (hiit) and moderate-intensity continuous training (mict) on serum myonectin levels, using matched training volumes for both interventions. methods: twenty-four male wistar rats, aged 18 to 20 weeks, were randomly assigned to three groups of eight: control, mict, and hiit. the training groups participated in hiit and mict programs (three days per week) on a treadmill for eight weeks. measurements included serum glucose, insulin, myonectin, and the homeostasis model assessment of insulin resistance (homa-ir). additionally, the weight of the flexor hallucis longus (fhl), gastrocnemius muscles, and epididymal and retroperitoneal fat pads was recorded. results: both hiit and mict significantly reduced weight gain and fat mass (epididymal and retroperitoneal) compared to the control group (p < 0.05). eight weeks of hiit significantly decreased serum insulin levels and homa-ir compared to both the control and mict groups (p < 0.05). no significant differences in serum myonectin levels were observed between the groups. conclusions: this study suggests that hiit is more effective than mict in improving metabolic status in rats, though it does not significantly affect serum myonectin levels.