Grant: CIHR Fellowship

Physical inactivity is associated with many negative health outcomes, including impaired thinking abilities and increased dementia risk. Older adults become inactive for many reasons. They may become inactive over time due to chronic conditions (e.g., arthritis, lung disease), or acutely due to bed rest resulting from injury, surgery, or hospitalization. Bed rest is a reality for many older adults and often is a "tipping point" for functional and cognitive decline and loss of independence. Exercise is beneficial for both cognitive and brain health. But it is currently unknown whether exercise training during periods of bed rest can reduce the negative impact of inactivity on older adults' cognitive and brain health during physical inactivity periods. Thus, maximizing on an opportunity provided by CIHR and the Canadian Space Agency, we will determine: 1) effects of daily physical exercise sessions in counteracting the effects of experimental bed rest on cognitive function (i.e., thinking abilities); 2) how both bed rest and sessions of exercise impact cognitive function in adults aged 55 to 65 years old; and 3) factors that moderate the effects of bed rest and exercise on cognitive function. Twenty to 24 healthy male and female middle-aged and older adults aged 55 to 65 will be randomized to 14 days of bed rest with three physical exercise daily sessions (60 minutes total) or a control group (bed rest only). The protocol also includes five days of adaptation and seven days of recovery. Results will help to understand how to prevent the acceleration of cognitive decline due to bed rest. A better understanding of how both physical inactivity and exercise impacts cognitive function will guide future strategies to shape cognitive aging during transitions in care positively. Also, it will provide us more evidence to prescribe individualized physical activity recommendations for healthy cognitive aging.