April 13 (UPI) -- Lack of physical activity may increase a person's risk for more severe COVID-19, as well as death from the disease, according to a study published Tuesday by the British Journal of Sports Medicine.
People with the virus who exercised little during the two years before becoming infected were about twice as likely to be admitted to the hospital, the data showed.
In addition, they had a 2 1/2 times higher risk for death compared with infected people who consistently met physical activity guidelines before the pandemic, the researchers said.
"We have known for a long time that people who are inactive are at higher risk of many diseases such as high blood pressure, diabetes and [heart] disease," study co-author Dr. Robert Sallis told UPI in an email.
"In relation to COVID-19, our study found that physical inactivity was the strongest ... [among other] commonly cited modifiable risk factors," said Sallis, co-director of sports medicine at Kaiser Permanente Medical Center in Fontana, Calif.
Several common, chronic health problems put people at higher risk for serious illness from the virus, including diabetes, obesity and heart disease, according to the Centers for Disease Control and Prevention.
In many cases, risk for these health problems also increases with lack of physical activity, Sallis and his colleagues said.
For this study, the researchers compared outcomes -- hospitalizations, deaths or recoveries -- in 48,440 adults diagnosed with COVID-19 between January and October 2020.
The study participants' average age was 47 and, on average, they had a body weight that met the criteria for obesity, the researchers said.
About 40% of all adults in the United States are obese, according to the CDC.
Around half of the participants had no underlying health conditions, while 18% had one and 32% had two or more, Sallis and his colleagues said.
All study participants reported their levels of regular physical activity to Kaiser Permanente outpatient clinics at least three times between March 2018 and March 2020.
About 7% were consistently meeting physical activity guidelines established by the CDC, which urge 150 or more minutes per week of vigorous exercise, according to the researchers.
However, 15% were consistently inactive, while the remainder reported some activity.
Of the study participants, 9% were admitted to the hospital due to COVID-19 and about 3% required treatment in the intensive care unit, the data showed.
Two percent of the study participants died from the virus.
After researchers took race, age and overall health into account, they determined that adults with COVID-19 who were consistently physically inactive were more than twice as likely to be admitted to the hospital compared to those who met CDC exercise recommendations.
They also were 73% more likely to require intensive care and 2 1/2 times more likely to die of the infection compared to those with a healthy exercise routine.
In addition, COVID-19 patients who were consistently inactive before infection also were 20% more likely to be hospitalized, 10% more likely to need intensive care unit treatment and 32% more likely to die from the virus than those who were doing at least some physical activity regularly.
Among study participants, physical inactivity was surpassed only by advanced age and a history of organ transplant as a risk factor for severe COVID-19, the researchers said.
"Regular physical activity is associated with improvements in lung capacity and cardiovascular and muscular functioning that may serve to lessen the negative impacts of COVID-19 if it is contracted," Sallis said.
"Also, it is well known that immune function improves with regular physical activity, and those who are regularly active have a lower incidence, intensity of symptoms and death from viral infections."