The Effects Of Different Exercise Modes On Obesity-related Muscle Atrophy In Mice

Obesity has become a global health issue, often accompanied by complications such as obesity-related muscle atrophy. While exercise has been reported to improve various obesity-related diseases, there is limited research focused on exercise modes, and it remains unclear which exercise mode is more effective in ameliorating obesity-related muscle atrophy. PURPOSE: To compare the effects of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on obesity-related muscle atrophy in mice under the premise of the same exercise distance, providing a scientific basis for exercise interventions for obesity-related muscle atrophy. METHODS: Male C57BL/6 mice were divided into 6 groups (each n = 12): standard chow diet, standard chow diet + MICT, standard chow diet + HIIT, high-fat diet, high-fat diet + MICT, and high-fat diet + HIIT. The study evaluated the effects of 8 weeks of treadmill training with different exercise modes on muscle mass, muscle index, muscle fiber cross-sectional area, muscle lipid deposition, and the expression of muscle atrophy marker genes Murf-1 and Atrogin-1 in the gastrocnemius muscle of mice exposed to 20 weeks high-fat diet. RESULTS: Compared to high-fat diet group, both exercise modes improved the decrease in gastrocnemius muscle index (MICT+18.8% vs. HIIT+17.6%, not significant), muscle fiber atrophy (MICT+15.5% vs. HIIT+13.7%, not significant), and muscle lipid deposition (MICT-19.8% vs. HIIT-17.1%, not significant). No significant difference was observed between the two exercise modes. At the gene level, compared to high-fat diet group, both MICT and HIIT exercise modes could significantly down-regulate the expression of Murf-1 (MICT-62.4% vs. HIIT-52.6%, p < 0.01) and Atrogin-1 (MICT-43.3% vs. HIIT-29.8%,p < 0.01). The down-regulation caused by MICT was significantly greater. CONCLUSION: Considering exercise mode comfort and genetic evidence, MICT mode might be more suitable for exercise interventions in obesity-related muscle atrophy.