Terence Dwyer
Over an average week, adults in the United Kingdom living with chronic disease spend 61 minutes (9%) less on moderate activity — such as gardening, brisk walking and housework — and 3 minutes (11%) less on vigorous activity — such as running and aerobics — than their healthy peers.
Perhaps this comes as a surprise. After all, few of us would question the health benefits of keeping moving and getting our heart rate racing. Physical activity guidelines, such as those developed by the UK’s National Institute for Health and Clinical Excellence, specifically refer to the importance of increasing physical activity for chronic disease management.
So why have we observed a gap in activity levels between those living with chronic disease and those without?
Our research, recently published in the International Journal of Epidemiology, canvassed more than 96,000 adults aged 40 years or older from the UK Biobank, of whom 44% had at least one chronic disease. Among the people with chronic disease, the average age was 63.5 years for women and 65.5 years for men.
We measured physical activity levels of both groups using accelerometers (devices that record ‘bodily movement’ and are worn like a watch on participants’ wrists) over 7 days, then categorised their activity by degree of intensity.
Unlike many previous studies that have relied on self-reporting of activity, which is inevitably subjective and often fails to capture routine or brief movements such as climbing the stairs, our objective measure offers a more accurate and complete picture.
One explanation for the difference is that those with chronic disease have been ‘habitually’ inactive, often long before their condition first manifested. After all, physical inactivity is associated with an increased risk of major chronic disease and, once risk becomes reality, it can be difficult for individuals to change their activity levels.
Indeed, some chronic diseases, such as respiratory or cardiovascular disorders, can limit people’s capacity for exercise, owing to a reduced supply of oxygen, while musculoskeletal disorders can affect their ability to engage in everyday activities. Mental health disorders might affect motivation to be active and, across the entire study population, we found that those with mental health disorders had the lowest levels of moderate activity, spending 2.4 hours less per week on this type of activity than those without any chronic disease (their healthy peers were moderately active for an average of 11.8 hours per week).
However, not all chronic conditions directly affect capacity for exercise. Therefore, we must consider other factors, such as the possible impact of the ‘sick role’. The very fact of having a chronic disease seems to influence people to be less physically active. So functional and behavioural limitations may both be at the root of this difference in activity.
It is therefore crucial that those with chronic conditions receive appropriate clinical guidance and targeted programs to ensure they accrue the health benefits of adequate physical activity — recommended to be at least 150 minutes of moderate intensity activity per week for adults — and stem the onset of progressive and multiple disease profiles.
Read more:
Barker J, Smith-Byrne K, Doherty A, et al. Physical activity of UK adults with chronic disease: cross-sectional analysis of accelerometer measured physical activity in 96,706 UK Biobank participants. Int J Epidemiol 2019; Feb 5. https://doi.org/10.1093/ije/dyy294.
Terry Dwyer is a Professor of Epidemiology and James Martin Senior Fellow at The George Institute for Global Health at the University of Oxford.
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