Acute and chronic effect of two different intensity interval training on hypertrophic and atrophic factors in healthy male wistar rats

Background In recent years, several peptides that have significant effects on the body's homeostasis and metabolism, particularly in skeletal muscles, have been discovered. These peptides include Myostatin, Follistatin, and Atrogin-1, which influence the growth of skeletal muscles and fat tissue, thus impacting overall body health. In the past years, few researches have compared the acute and chronic effects of exercise training on these factors. Also, the effect of exercise intensity on these factors is unclear. Therefore, the aim of this research is to compare the acute and chronic effect of intermittent exercise with different intensity on myostatin, follistatin and atrogin-1. Method The current research involves an experimental study in which healthy rats were divided into 6 groups. The rats underwent a chronic training period of 6 weeks, training 3 days per week with varying intensities. The high-intensity interval training (HIIT) was conducted at 100% of maximal capacity, while the moderate-intensity interval training (MIIT) was conducted at 70% of maximal capacity. Notably, rats from the acute groups were sacrificed immediately after one training session. Data were analyzed using one-way ANOVA and LSD method at p ≤ 0.05. Result The results of the study on gene expression in response to exercise show significant findings. In the chronic high-intensity interval training (HIIT) group, there is a significant decrease in myostatin gene expression, while no significant change is observed in the acute training groups. Additionally, follistatin gene expression increases significantly in the exercise groups, with no significant change reported in the acute exercise groups. Furthermore, the study reveals a significant decrease in the expression of the atrogin-1 gene in both acute and chronic training groups compared to the control. Conclusion The present research suggests that more time is required for exercise to impact muscle hypertrophy, and acute exercise does not significantly affect myostatin and follistatin changes. However, both acute and chronic training lead to a notable decrease in the expression of the atrogin-1 gene, indicating that it is more sensitive to exercise than the myostatin and follistatin genes.