Regular physical activity reduces the risk of severe Covid-19, suggests a new study published in the British Journal of Sports Medicine.¹

This retrospective observational study analyzed electronic health records (EHRs) of 48,440 individuals, aged ≥18 years, who tested positive for Covid-19 between 1^st January 2020 and 21^st October 2020. The selected participants had at least three self-reported exercise measurements (exercise vital sign) documented from 19th March 2018 to 18th March 2020 i.e. 2 years prior to the pandemic lockdown in California in March 2020. “This study was conducted at Kaiser Permanente Southern California (KPSC), which is an integrated healthcare system that serves approximately 4.7 million residents in Southern California at 15 medical centres.” The objective of the study was to decipher any association of physical activity with hospitalization rates, intensive care unit (ICU) admissions and mortality.

Based on the US Physical Activity Guidelines, the study participants were categorized into three groups: consistently inactive (0-10 min/week), some activity but below guidelines (11 - 149 min/week) and consistently meeting guidelines (≥150 min/week). The US Physical Activity Guidelines recommend moderate to vigorous physical activity for at least 150 minutes in a week.

Analysis of data show that 6.4% participants were consistently meeting PA guidelines, 14.4% were consistently inactive, while the remaining pursued some activity.

The risk of hospitalization was increased 2.26 times in patients who were consistently inactive. They also had a higher risk of being admitted to the ICU (OR 1.73) and dying (OR 2.49) due to COVID-19 compared to patients who consistently met physical activity guidelines.

Similarly, when compared to persons doing some physical activity, those who were consistently inactive continued to be at a greater risk of hospitalisation (OR 1.20), admission to the ICU (OR 1.10) and death (OR 1.32) due to COVID-19.

Other than age, pregnancy and a history of organ transplant, the risk of hospitalization and severe Covid-19 outcomes was highest for consistently inactivity.

“Covid-19 has been described as a syndemic of COVID-19 and chronic diseases.”² Obese persons and those with underlying comorbid conditions such as heart disease, diabetes are known to be more likely to develop severe Covid-19. A sedentary lifestyle is a major risk factor for these lifestyle disorders. It is hypothesized that exercise can reduce the inflammation in Covid-19 by reducing visceral adiposity, a source for proinflammatory cytokines.  

This study has for the first time shown physical activity as a modifiable risk factor for severe Covid since patients who consistently met the recommended physical activity guidelines had more favorable outcomes. Even some levels of physical activity was associated with reduced risk of hospitalization, ICU admissions and mortality. Hence regular physical activity should also be suggested as a measure to reduce disease severity in addition to other protective behaviors such as masking, hand washing, and physical distancing. The message that regular activity is a must, but some activity is better than nothing, should percolate down to the masses.

Based on their findings, the study authors also “recommend efforts to promote physical activity be prioritised by public health agencies and incorporated into routine medical care”.

References

1. Sallis R, et al. Physical inactivity is associated with a higher risk for severe COVID-19 outcomes: a study in 48 440 adult patients. Br J Sports Med. 2021 Oct;55(19):1099-1105. doi: 10.1136/bjsports-2021-104080
2. Jean-Pierre Després. Severe COVID-19 outcomes - the role of physical activity. Nat Rev Endocrinol. 2021 Aug;17(8):451-452. doi: 10.1038/s41574-021-00521-1.