Stay Fit & Your COVID Shot May Work Even Better

TUESDAY, Oct. 25, 2022 (HealthDay News) -- The more often you work out, the more effective your COVID-19 vaccination will be, a new study suggests.

Fully vaccinated folks who clocked high weekly levels of physical activity were nearly three times less likely to land in the hospital with COVID, compared to those who got the jab but didn't exercise often, researchers found.

"The findings suggest a possible dose response, where high levels of physical activity were associated with higher vaccine effectiveness," said the researchers led by Dr. Jon Patricios, from Wits Sport and Health (WiSH) and School of Clinical Medicine at the University of the Witwatersrand in Johannesburg-Braamfontein, South Africa. The study was published Oct. 24 in the British Journal of Sports Medicine.

"Public health messaging should encourage physical activity as a simple, cost-effective way of enhancing vaccine effectiveness to mitigate the risk of severe COVID-19 illness requiring hospital admission," the researchers added in a journal news release.

For the study, researchers analyzed medical records for nearly 200,000 health care workers belonging to a medical insurance plan with benefits or promotions that required them to wear an activity tracker.

Participants were placed in three different physical activity categories -- high, medium or low -- based on the average weekly amount they worked out during the two years prior to the start of the study.

The research team then tracked the outcomes of those who contracted COVID.

High-level exercisers who got more than 150 minutes of physical activity every week were 86% less likely to have a case of COVID contracted following their vaccination land them in the hospital, researchers found.

Likewise, people who averaged 60 to 149 minutes of physical activity weekly -- the medium category -- had a 72% reduced risk of hospitalization from COVID.

But the vaccine was only 60% effective in those with the lowest levels of exercise, under 60 minutes a week, researchers found.

It's not clear why physical activity might enhance COVID vaccination, the researchers wrote.

Exercise might cause the body to produce more antibodies in response to the vaccine, or prompt the immune system to be sharper in detecting and attacking the coronavirus, they said.

More information

The U.S. Centers for Disease Control and Prevention has more about COVID-19 vaccination.

SOURCE: British Journal of Sports Medicine, news release, Oct. 24, 2022