Grant: Discovery Grants Program - Individual

Sedentarism is any waking activity done in a seated, reclined, or lying position that requires low energy expenditure. Most Canadians are spending over 10 hours per day engaging in sedentary activities like driving their car, sitting at a desk, or laying on the couch watching television. Research clearly shows that engaging in high volumes of sedentary time is associated with a high risk of disease and disability. Experimental studies show that sitting for as little as 2 hours can lead to impairments in the function of our vasculature and can create metabolic disruptions. Studies also show that interrupting long sitting sessions with some movement can diminish these negative effects. Research from my lab shows that simply sitting for 4 hours can lead to an increase in pro-inflammatory biomarkers, and that interrupting a 4-hour session of sitting with light or high intensity walking or cycling can limit this response. My research has also identified new markers that can be used to understand sedentary physiology. A promising new area is the microbiome. The microbiome is the collection of all microbes (e.g. bacteria, fungi, viruses, and their genes) that naturally live inside the human body. It has been associated with a range of physiological outcomes, but has never been investigated in the context of sedentary physiology. My Discovery Grant research program is aimed at understanding how different markers will respond to different amounts of sedentarism, and how much movement is needed to overcome that negative response. I will be conducting experimental studies where participants will provide saliva and blood samples, perform exercise tests, and wear an activity monitor so that we can understand how different people (males vs. females; fit vs. unfit) respond to different amounts of sedentarism, and how much movement these people need to prevent this response. I will also be using saliva to look at changes in the oral microbiome by having people increase their sedentary time for 1-2 weeks. Finally, I will create a database to answer a number of research questions related to factors that affect the response to sedentary sessions. For example, age or diet might make some people more responsive and thus more susceptible to the negative effects of sitting. Sedentarism costs our healthcare system billions of dollars in direct and indirect costs each year. Understanding sedentary physiology, and the sex differences in this response, may provide us with new therapeutic targets in the future and inform the development of novel, evidence-based interventions. This work will also lead to methodological developments that can be used in other fields to advance our understanding of the impact of physiological stressors such as space travel, prolonged endurance exercise, or infectious disease.