More Active, Less Risk for Severe COVID-19?

Does staying active reduce the risk of severe outcomes with COVID-19? A new study suggests this possibility. In fact, the authors of this study found that being inactive was a top risk factor for landing in the hospital or dying from COVID-19. Only advanced age or an organ transplant had higher risks.

This makes sense. But a bit of perspective would be wise. Some news reports are exaggerating the potential benefit. When they describe exercise as “shielding” COVID-19 patients from death, they are simply wrong. For that kind of protection, people need a vaccine. Not wellness mythology.

An Observational Study

The key thing to know is that this was a big observational study. With data from Kaiser Permanente, researchers analyzed risk factors for 48,440 patients with COVID-19. The analysis was solid and the link between physical activity and COVID outcomes was strong. In fact, for someone who was consistently inactive, the risk of landing in the hospital doubled. The risk of death was two and a half times higher. These are big increases in risk. They demand our attention.

However, confounding factors also demand our attention. The authors know this and explain it in their paper:

“Importantly, because this is an observational study, it is not possible to definitively conclude PA is causally related to less severe COVID-19 outcomes. These associations could potentially be in reverse; that is, those who have more significant underlying illness may be less likely to include PA in their daily routine or lack the capacity to do so. There is also the potential issue of residual confounding due to unmeasured confounders or measurement error.”

Wellness Magic

The magical powers of wellness are quite appealing here. Everyone likes to feel they have control over their destiny. Tell us we can work out to prevent having a bad case of COVID and we want to believe it. Plus, what’s the harm? Physical activity is indeed good for us. One year into this pandemic, it’s clear that getting outside for some physical activity is safe as well as beneficial.

But it’s no substitute for getting a vaccine. At best, this research suggests that staying active might cut your risk of a bad COVID-19 outcome in half. A vaccine cuts it to almost nothing. That’s about as close to a miracle as you will ever find.

Click here for the study and here for further perspective. For perspective on reporting about COVID-19, click here.

Walk Along the Banks of the Seine Near Asnieres, painting by Vincent van Gogh / WikiArt

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April 19, 2021