Study finds regular physical activity linked to lower risk for COVID-19, mortality

Key Takeaways:

• Adults who regularly participated in moderate to vigorous physical activity had an 11% lower risk for COVID-19, in addition to lower risks for hospitalization, severe disease and mortality.
• The systemic review and meta-analysis build upon existing evidence of a correlation between physical activity and COVID-19 as well as other respiratory and chronic illnesses.
• Study limitations include the lack of data with participants who had contracted the omicron variant of SARS-CoV-2.

Regular physical activity was associated with a lower risk for developing COVID-19 and experiencing adverse outcomes of COVID-19, including severe disease and mortality, a study published in the British Journal of Sports Medicine found.

Researchers said at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity per week, equivalent to 500 metabolic equivalents of task, was needed to achieve the greatest protection.

According to Yasmin Ezzatvar MD, of the University of Valencia in Spain, and colleagues, the connection between physical activity and COVID-19 likely involves metabolic and environmental factors.

“A growing body of evidence from several studies has suggested that increased physical activity may modulate the disease course and reduce the development of negative outcomes in confirmed cases of COVID-19,” Ezzatvar and colleagues wrote. “The aim of the present study was to quantify the association between physical activity and risk of SARS-CoV-2 infection, COVID-19-associated hospitalization, severe illness and death due to COVID-19 in adults.”

The researchers analyzed 16 studies with a total of 1,853,610 adult participants. Among them, 53% were women, and the median age of participants was 53 years.

Compared with inactive adults, the researchers reported that those who took part in regular physical activity possessed an 11% lower risk for developing COVID-19 (RR = 0.89; 95% CI, 0.84-0.95), a 36% lower risk for hospitalization (RR = 0.64; 95% CI, 0.54-0.76), 44% lower risk for COVID-19 severity (RR = 0.66; 95% CI, 0.58-0.77), and 43% lower risk for death from COVID-19 (RR = 0.57; 95% CI, 0.46-0.71).

Current evidence suggests that regular moderate intensity physical activity enhances anti-inflammatory responses in the body, helping to revert lymphocytopenia in patients with COVID-19, according to the researchers. Greater strength of cardiorespiratory and muscular fitness are also possibilities.

Ezzatvar and colleagues noted several limitations to the study, the main of which involved the risk that the pooled estimates are subjected to confounding due to contrasting variables and uncontrolled confounding over the dozens of studies.

Additionally, participants of the 16 studies were mainly exposed to the beta and delta variants of SARS-CoV-2, not the omicron variant that developed afterwards and made up 88.9% of total U.S. COVID-19 cases in the week ending Aug. 20, per the CDC.

While further research is not only warranted due to the presence of new variants but also from “heterogeneity and risk of publication bias,” Ezzatvar and colleagues said the results could help to develop further public action and treatment for COVID-19.

“These findings may help guide physicians and healthcare policymakers in making recommendations and developing guidelines with respect to the degree of physical activity that can help reduce the risk of infectivity, hospitalization, severity and mortality of COVID-19 at both the individual and the population level, especially in high-risk patients,” they wrote.

References:

• COVID Data Tracker. https://covid.cdc.gov/covid-data-tracker. Accessed Aug. 24, 2022.
• Ezzatvar Y, et al. Br J Sports Med. 2022;doi:10.1136/bjsports-2022-105733.
• Regular physical activity linked to lower risk of COVID-19 infection and severity. https://www.eurekalert.org/news-releases/962275. Published Aug. 22, 2022. Accessed Aug. 24, 2022.