Grant: Operating Grant: Understanding the Health Impact of Inactivity

Physical activity has multiple benefits for our health, including cognitive and brain health. Unfortunately, many adults become physical inactive with age. Studies repeatedly show that physical inactivity is associated with numerous negative health outcomes, including cognitive impairment and increased dementia risk. Older adults become physically inactive for many reasons, secondary to chronic conditions such as arthritis or lung disease, or acutely, due to bed rest as a result of injury, surgery, or hospitalization. It is important to note that bed rest is a reality for many older adults and often is a "tipping point" for subsequent decline in function and independence. Whether implementing bouts of physical exercise during periods of physical inactivity, such as bed rest due to injury or illness, may effectively mitigate the negative consequences of physical inactivity is not well established. Moreover, the exact mechanisms by which physical exercise may protect older adults' cognitive and brain health during periods of physical inactivity is not well understood. However, a better understanding will advance the development of novel interventions and rehabilitation strategies to counter the adverse effects of physical inactivity on cognitive health in older adults. Thus, maximizing on an opportunity provided by CIHR and the Canadian Space Agency, we will determine: 1) the effects of 14 days of bed rest on cognitive and brain outcomes in adults aged 55 to 65 years old; 2) the impact of daily bouts of moderate to vigorous physical exercise in mitigating the effects of bed rest on cognitive function; and 3) the mechanisms (i.e., how) by which bed rest and impacts cognitive and brain function. Given the immense health and financial burden imposed by cognitive impairment, and majority of older adults are physically inactive, our results will guide future strategies to positively shape the path of cognitive aging in health and during transitions in care.