Elucidating How Physical Activity and Sleep Relate to Optimal Cognitive Ageing

Increased longevity is one of the greatest success stories in public health. However, ageing is accompanied by cognitive decline which affects people's daily functioning and, if it develops to dementia, their ability to live independently. By 2050, the number of people who develop dementia will triple to 152 million. The aim of this project is to precisely examine how physical activity (PA) and sleep, both modifiable lifestyle factors, are related to cognitive function and which role they can play in optimal cognitive ageing. To do so, a longitudinal study will be conducted, with objective measures of PA, sleep and cognition in midlife and older adults. This project will meet the current need for longitudinal studies with objective PA and sleep data, as well as provide, for the first time, in-depth information on associations of type of PA (aerobic vs muscle strengthening), characteristics of sleep (quality vs quantity) with specific cognitive domains (executive function and memory). Furthermore, although PA and sleep are related, the behavioural dynamics of combinations of PA and sleep on cognition has never been studied before. To fill this gap, these relationships will be examined with an innovative statistical approach, looking at data across a 24-hour period. The resulting deeper understanding of the precise relationship between PA, sleep and cognitive function will contribute to the development of preventive interventions for maintaining cognitive health at older age.