Feature: Physical activity reduces risks of severe COVID-19 outcomes, study shows

Activity-BANNER.pngby Max Martin, MMJC'19

Moderate physical activity in adults is associated with significant protective effects from severe COVID-19 outcomes, a new international study shows.

The study, led by the University of the Witwatersrand in Johannesburg, South Africa, along with researchers at Western University, found adults with high and moderate physical activity levels had significantly better outcomes than those with low activity levels when contracting COVID-19.

“Findings from this study – from a low-resource setting, such as South Africa – reiterate the public health importance of healthy lifestyles, including regular physical activity, to mitigate the negative health impact of the current pandemic,” said Dr. Saverio Stranges, professor and chair of epidemiology and biostatistics at Western’s Schulich School of Medicine & Dentistry.

Researchers measured physical activity data from more than 65,000 adult patients with COVID-19 from March 19, 2020 to June 30, 2021.

Participants were grouped by activity level – low, moderate and high – with low representing fewer than 60 minutes per week; moderate, which included those who were active 60 to 149 minutes per week; and high, which reflected more than 150 minutes of activity.

Adults with high and moderate physical activity levels were associated with lower rates of hospitalization, ICU admission, ventilation and death, compared to those with lower physical activity.

The study, published in the British Journal of Sports Medicine, also showed the apparent protective effects of physical activity extend to those with chronic medical conditions.

“Regular physical activity, even of low to moderate intensity, may reduce the risk of morbidity and mortality from COVID-19 infection, even among people with chronic medical conditions which may typically worsen the prognosis,” Stranges explained.

This study is unique in that the researchers accessed participants’ physical activity records captured by smart devices, clocked gym attendance, and mass event participation as part of a health promotion program linked to private medical insurer Discovery Health.

"This was a great example of international collaboration coming together to answer a critical question: Is physical activity associated with protection against severe outcomes of COVID-19?” said Dr. Jane Thornton, assistant professor of family medicine and epidemiology and biostatistics at Schulich Medicine & Dentistry. “This was the first study to show this positive association using objectively measured physical activity, for example, using data from a smart device versus survey questions.”

Thornton said the paper is aptly titled, “Small steps, strong shield,” as the research shows the level of physical activity needed to have protective effect against severe COVID-19 outcomes is actually lower than the generally recommended activity levels for adults – which is about 150 minutes of moderative to vigorous physical activity per week.

"The data reinforce the need to make access to physical activity easier during pandemics, as part of government policy in fact, and promote its beneficial effects in health care more broadly,” Thornton said.

She said the study is also significant as the data is taken from a country where SARS-CoV-2 variants were prevalent.

Yun-Hee Choi, professor of epidemiology and biostatistics at Schulich Medicine & Dentistry, was also involved in the study and provided guidance on data analyses.

“This was an excellent example of synergistic international collaboration,” said Dr. Jon Patricios, professor, Wits University, and senior author on the study. “The input of biostatistical and physical activity experts from Western University proved invaluable in analysing this unique data set.”