The participants, with an average age of 76, were asked to report their pre-pandemic “lifestyle factors,” including physical activity levels, and were split into three categories — “inactive,” “insufficiently active,” or “sufficiently active” — based on guidelines that recommend 150 to 300 minutes of “moderate intensity” exercise every week, according to the study.
The adults in the “sufficiently active” group had a 10 percent lower chance of contracting COVID-19 and were 27 percent less likely than inactive adults to be hospitalized from COVID-19, the study found.
“Those who adhered to the physical activity guidelines before the pandemic had lower odds or risk of developing or being hospitalized with COVID,” Muñoz-Vergara said.
The results align with other recent studies, including one in California and another led by Harvard-affiliated researchers, Muñoz-Vergara said. But this study has “contributed more because it expanded those results” in a large population of older adults, he said.
Muñoz-Vergara said 61,000 adults is “considered a large cohort” in self-reported studies Still, the authors and an expert who was not affiliated with the study acknowledged that the findings had limitations.
Its participants were predominantly college-educated women, which makes it hard to apply the results to the general public, said Sabrina Assoumou, an infectious disease physician at Boston Medical Center and an associate professor at Boston University Medical School.
“I would love to see this in a more diverse group of people,” Assoumou said. “A group from other racial-ethnic backgrounds to explore this, and also people from different socioeconomic backgrounds. When you’re reading research, you wonder how generalizable is this finding and so seeing this replicated in other groups would be helpful.”
Assoumou also noted that the data did not come from medical records but was self-reported. Muñoz-Vergara also pointed out that the number of reported COVID-19 cases could have been “underestimated.”
“There were people that were asymptomatic cases that we have no way to know if they had COVID,” he said. “We always have to think about those limitations.”
The definition of “severity” is “based on hospitalization alone,” Muñoz-Vergara said, and some individuals may have been very sick but did not go to a hospital.
Muñoz-Vergara and Assoumou also cited other reasons the “sufficiently active” group may have had less severe COVID-19 infections, such as being vaccinated and taking steps to avoid contracting the virus.
“Maybe the people who were more physically active in the beginning are the people who are more likely to wear masks and avoid crowds,” Assoumou said.
Still, Assoumou said the study builds on prior research about the benefits of exercise for the lungs and “neurologic status.” It’s “encouraging,” she said.
“It goes with what we know, exercise is great for you,” she said.
The study can also pave the way for further research, Assoumou said.
“Big picture, it’s a helpful data point that builds on what we already know related to physical activity,” she said. “Then, it brings up some intriguing questions, like can we now quantify how much physical activity do you actually need to have an impact on your risk of infection or hospitalization?”
Muñoz-Vergara said he wants to keep using this “rich dataset” to explore the association between pre-pandemic physical activity and the risk of depression during the first year of the pandemic, and is hoping to publish a new study in the coming months.
Ava Berger can be reached at ava.berger@globe.com. Follow her @Ava_Berger_.