The impacts of vitamin D status and HIIT on physical performance and frailty during aging

维生素D状态和HIIT对衰老过程中身体机能和虚弱的影响 虚弱是一种与年龄相关的渐进性疾病，会增加对残疾的易感性， 住院和死亡，并可能影响多达10%的5000万人目前超过 65岁的人，以及近70%的85岁以上的人。缺乏活动和维生素D不足也是 在老年人群中非常普遍，两者都与虚弱有关。高强度间歇 训练（HIIT）可能是一种新的治疗策略，因为HIIT安全地提供了大量的力量， 耐力的好处与较低的时间承诺。该项目的目标是描述 补充维生素D在与年龄相关的虚弱中的作用，以及维生素D状态是否可以 介导对HIIT的反应。此外，该项目将研究肌肉干细胞的作用， 以及介导这种反应的潜在microRNA（miRNA）信号。维生素D不足 从6到18个月大的老鼠导致身体表现下降。此外，HIIT 增强24至28个月大的运动小鼠的身体表现并减少虚弱 （相当于65-80岁的人）。该提案的假设是，维生素D 充足是必要的，以优化干细胞的功能，身体的表现，和反应， 锻炼，以及减少衰老过程中的虚弱。为了验证这一假设，维生素D充足的小鼠将 与那些在身体表现和虚弱方面维生素D不足的人相比 在老化和HIIT反应中。这项研究将解决维生素D领域的关键空白， 关于维生素D在调节身体机能方面的作用， 表现、虚弱和对运动的反应。在本研究中使用小鼠模型将允许 了解HIIT和维生素D对人体等效的纵向影响， 十年，否则很难在临床研究中确定，由于长度以及 混淆生活方式和遗传混杂因素的贡献。我们的研究结果将 为成功实施运动和维生素D提供临床试验蓝图 补充，从而提高我们老龄化人口的护理质量。

The impacts of vitamin D status and HIIT on physical performance and frailty during aging Frailty is a progressive age-associated condition that raises susceptibility to disability, hospitalization, and death and may affect as many as 10% of the 50 million individuals currently over the age of 65, and nearly 70% of those over the age 85. Inactivity and vitamin D insufficiency are also highly prevalent in older populations, and both are correlated with frailty. High intensity interval training (HIIT) may be a novel therapeutic strategy as HIIT safely provides substantial strength and endurance benefits with lower time commitments. The goals of this project are to characterize the role of vitamin D supplementation in age-related frailty, and whether vitamin D status can mediate the response to HIIT. Additionally, this project will investigate the role of muscle stem cells and underlying microRNA (miRNA) signaling in mediating this response. Vitamin D insufficiency from 6 to 18 months of age in mice leads to declines in physical performance. Additionally, HIIT enhances physical performance and reduces frailty in mice exercised from 24 to 28 months of age (equivalent to a 65-80 year old human). The hypothesis of this proposal is that vitamin D sufficiency is necessary to optimize stem cell function, physical performance, and the response to exercise, as well as reduce frailty during aging. To test this hypothesis, vitamin D sufficient mice will be compared to those that are vitamin D insufficient in terms of physical performance and frailty during aging and in the response to HIIT. This study will address critical gaps in the vitamin D field, which is stymied by conflicting studies regarding the role of vitamin D in regulating physical performance, frailty, and the response to exercise. The use of a mouse model in this study will allow an understanding of the longitudinal impacts of HIIT and vitamin D over the human equivalent of decades, which are otherwise difficult to determine in clinical studies due to length as well as the obfuscating contributions of lifestyle and genetic confounders. Findings from our proposed study will provide a clinical trial blueprint for successful implementation of exercise and vitamin D supplementation, thus improving the quality of care for our aging population.