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

维生素D状态和低氧血症对衰老过程中体能和体质的影响 虚弱是一种与年龄相关的进行性疾病，会增加残疾的易感性， 住院和死亡，并可能影响目前5000万人中多达10%的人 65岁，以及近70%的85岁以上的人。缺乏运动和维生素D不足也是 在老年人群中非常普遍，两者都与虚弱相关。高强度间隔 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和 耐力受益于较低的时间承诺。这个项目的目标是描述 补充维生素D在年龄相关性脆弱中的作用，以及维生素D状态是否可以 调停对HIIT的反应。此外，该项目还将研究肌肉干细胞的作用。 以及介导这一反应的潜在microRNA(MiRNA)信号。维生素D缺乏 从6个月到18个月大的老鼠会导致体能下降。此外，HIIT 增强24至28个月龄小鼠的运动能力和降低虚弱程度 (相当于一个65-80岁的人)。这项提议的假设是维生素D 充足是优化干细胞功能、身体性能和对 运动，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 在身体表现和虚弱方面与维生素D不足的人相比 在老化过程中和在对HIIT的反应中。这项研究将解决维生素D领域的关键空白， 关于维生素D在调节生理机能中的作用的相互矛盾的研究阻碍了这一点 表现、虚弱和对运动的反应。在这项研究中使用小鼠模型将允许 了解HIIT和维生素D对人体等量的纵向影响 几十年，否则很难在临床研究中确定，因为长度以及 混淆了生活方式和基因混杂因素的贡献。我们建议的研究结果将 为运动和维生素D的成功实施提供临床试验蓝图 补充，从而提高对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.