Grant: Master's Award: Canada Graduate Research Scholarships - Master's program

How we allocate time to sleep, sedentary behaviour (sitting), standing, and physical activity over a 24-hour day—collectively called movement behaviours—has major health implications. Historically, research examined these movement behaviours in isolation, overlooking their codependence. Newer research has studied how movement behaviours interact to affect health, but key limitations and knowledge gaps remain. Existing studies have mostly used cross-sectional designs. Most focus on disease outcomes like dementia and depression, leaving the positive side of mental health—like high well-being—unexplored. Furthermore, the devices used to measure movement behaviours in past studies are prone to measurement error. My research will examine whether the mixture of movement behaviours across the 24-hour day is linked to changes in mental well-being over time. I will use data from a cohort of 5,000 middle-aged adults. Movement behaviours were measured at age 46 using the activPAL device, which participants wore for 7 days to provide accurate estimates of time spent sleeping, sitting, standing, and being active. Changes in mental well-being were assessed using participants’ responses on the validated Warwick-Edinburgh Mental Well-Being Scale at ages 46 and 51. To capture the fact that movement behaviours are codependent parts of a 24-hour composition, I will use compositional data analysis methods tailored to this type of constrained data. Understanding how daily movement patterns relate to well-being may reveal simple, low-cost ways to support positive mental health and inform public health recommendations. Higher well-being is linked to stronger immune functioning, better pain tolerance, and increased longevity, as well as broader societal benefits such as lower healthcare costs.