Approved Research

Associations of physical activity and physical function with the risk of COVID-19 infection, hospitalisation, and death.

Lay summary

Physical inactivity is associated with lowered immune function, higher levels of inflammation and poorer cardiovascular and metabolic health. Collectively, this may increase an individual's susceptibility to COVID-19 and their risk of developing severe and/or fatal health complications during the course of infection. Despite this, there is limited research exploring a protective role of physical activity against COVID-19 infection, particularly in at risk populations such as older adults and individuals with obesity.

Old age and obesity are linked with greater risk of COVID-19 hospitalisation and death. This may be partly due to the negative effects of aging and fat accumulation on inflammation and cardiovascular and metabolic health. However, increasing levels of physical activity may lessen these effects, as older adults and individuals with obesity who are physically active have been shown to have lower levels of inflammation and improved cardiovascular and metabolic health compared to their less active counterparts. Importantly, this suggests the potential for regular physical activity to reduce the burden of COVID-19 typically observed in such populations.

Therefore, this study aims to investigate the relationship between physical activity level and COVID-19 infection risk, hospitalisation and death, firstly independent of age and fatness, and then across different age groups and obesity categories. Moreover, as the health benefits of physical activity may occur largely through improving fitness and muscular strength, we also aim to provide insight into whether measures of physical function, such as walking speed and hand grip strength, may also be linked with COVID-19 outcomes. Further analysis will be undertaken to determine whether any protective associations of physical activity and/or physical function may be explained by certain health markers.

The findings from this project will provide evidence to support increased public health efforts to promote physical activity as a feasible and achievable lifestyle habit to reduce the national burden of COVID-19. The proposed research will also inform future management and prevention strategies for other common respiratory infections and/or subsequent coronavirus outbreaks. The project is estimated to last 12 months.

Scope extension:

Current scope

1) Identify the association of physical activity level and markers of physical function (walking speed and handgrip strength) with various COVID-19 outcomes (overall incidence, hospitalisation and death), independent of age and adiposity.

2) Investigate the association of physical activity level and physical function with COVID-19 outcomes across different age and adiposity groups. This will determine whether higher levels of physical activity and/or physical function are associated with lower COVID-19 burden in at risk groups (older adults and individuals with overweight/obesity).

3) Explore the potential cardiometabolic mechanisms through which any observed protective effects of physical activity and/or physical function on COVID-19 outcomes may be mediated.

4) Perform a series of sub-analyses where possible using DXA/MRI scan data, objective physical activity and cardiorespiratory fitness.

New scope (in addition to the above)

1) Identify the association of sedentary behaviour with various COVID-19 outcomes (overall incidence, hospitalisation and death), independent of age and adiposity.

2) Investigate the association of sedentary behaviour across different age and adiposity groups.

3) Explore the potential cardiometabolic mechanisms through which any observed effects sedentary behaviour on COVID-19 outcomes may be mediated.

Current scope

1) Identify the association of physical activity level and markers of physical function (walking speed and handgrip strength) with various COVID-19 outcomes (overall incidence, hospitalisation and death), independent of age and adiposity.

2) Investigate the association of physical activity level and physical function with COVID-19 outcomes across different age and adiposity groups. This will determine whether higher levels of physical activity and/or physical function are associated with lower COVID-19 burden in at risk groups (older adults and individuals with overweight/obesity).

3) Explore the potential cardiometabolic mechanisms through which any observed protective effects of physical activity and/or physical function on COVID-19 outcomes may be mediated

4) Perform a series of sub-analyses where possible using DXA/MRI scan data, objective physical activity and cardiorespiratory fitness.

(First) New scope (in addition to the above)

1) Identify the association of sedentary behaviour with various COVID-19 outcomes (overall incidence, hospitalisation and death), independent of age and adiposity.

2) Investigate the association of sedentary behaviour across different age and adiposity groups.

3) Explore the potential cardiometabolic mechanisms through which any observed effects sedentary behaviour on COVID-19 outcomes may be mediated.

(Second) New scope

1) Assess whether sleep health traits (i.e., sleep duration) modify the association of physical activity/sedentary behaviour with COVID-19 outcomes.