Neural and muscular mechanisms of age- and sex-related impairments in muscle function and fatigue in old and very old adults

Even in the absence of disease, ageing leads to impairments in muscle function, limiting the abilities of many older adults to perform daily activities, such as walking. These functional declines are due to ageing-related impairments in the brain, spinal cord, and muscles. However, these declines in function are poorly understood in adults over 80 years of age, which is especially true for older females, as these groups are typically omitted from human physiology research. To improve our understanding of ageing-related changes in muscle function, we will evaluate brain, spinal cord, and muscle function during force or power production and compare differences among young (18-30 years), old (60-69 years), and very old (over 80 years) females and males. The inclusion of very old adults is critical, as these individuals are most susceptible to impairments in muscle function. Furthermore, we are focusing our efforts on the thigh muscles, as they are vital for daily activities and mobility, and are greatly impacted by advancing age. This project will provide foundational knowledge to guide the development of interventions, such as age- and sex-specific exercise prescriptions, to restore muscle function and quality of life for older adults.