Skeletal muscle adapts to different exercise training modalities with age; however, the impact of both variables at the systemic and tissue levels is not fully understood. Here, adult and old C57BL/6 male mice were assigned to one of three groups: sedentary, daily high-intensity intermittent training (HIIT), or moderate intensity continuous training (MICT) for 4 weeks, compatible with the older group’s exercise capacity. Improvements in body composition, fasting blood glucose, and muscle strength were mostly observed in the MICT old group, while effects of HIIT training in adult and old animals was less clear. Skeletal muscle exhibited structural and functional adaptations to exercise training, as revealed by electron microscopy, OXPHOS assays, respirometry, and muscle protein biomarkers. Transcriptomics analysis of gastrocnemius muscle combined with liver and serum metabolomics unveiled an age-dependent metabolic remodeling in response to exercise training. These results support a tailored exercise prescription approach aimed at improving health and ameliorating age-associated loss of muscle strength and function in the elderly.

骨骼肌随着年龄的增长适应不同的运动训练方式；然而，这两个变量在全身和组织水平上的影响尚不完全清楚。在这里，成年和老年 C57BL/6 雄性小鼠被分配到三组之一：久坐、每日高强度间歇训练 (HIIT) 或 4 周的中等强度连续训练 (MICT)，与老年组的运动能力相适应。MICT 老年组主要观察到身体成分、空腹血糖和肌肉力量的改善，而成年和老年动物 HIIT 训练的效果不太明显。电子显微镜、OXPHOS 测定、呼吸测量和肌肉蛋白生物标志物显示，骨骼肌对运动训练表现出结构和功能适应性。腓肠肌的转录组学分析与肝脏和血清代谢组学相结合，揭示了运动训练引起的年龄依赖性代谢重塑。这些结果支持一种量身定制的运动处方方法，旨在改善老年人的健康状况并改善与年龄相关的肌肉力量和功能损失。