Now researchers say regular activity could help protect against severe Covid hospitalizations.
In a new study published in the British Journal of Sports Medicine, researchers and physicians at Kaiser Permanente Fontana Medical Center in Southern California, the University of California, San Diego, and other institutions found that Covid patients who regularly exercised before becoming sick were the least likely to be hospitalized, admitted to the ICU and die as a result of their illness.
The study looked at data from nearly 50,000 adult patients in California diagnosed with Covid-19 from January 2020 to the end of October 2020.
To measure activity levels, researchers asked each patient to self-report how many minutes they exercised each week. After analyzing their weekly physical activity with their Covid-19 response, researchers found that patients who were consistently inactive (less than 10 minutes a week) had a greater risk of hospitalization, admission to the ICU and death than those who worked out 150-plus minutes a week.
"Even after we controlled for variables such as obesity and smoking in the analysis, we still saw inactivity was strongly associated with much higher odds of hospitalization, ICU admission, and death compared with moderate physical activity or any activity at all," Dr. Robert E, Sallis, a family and sports medicine physician at the Kaiser Permanente Fontana Medical Center, who conducted the study, tells CNBC Make It.
As far as what kind of exercise, Sallis suggests following the U.S. Physical Activity Guidelines.
"Adults should do at least 150 minutes and up to 300 minutes a week of moderate-intensity physical activity, or 75 minutes to 150 minutes a week of vigorous-intensity aerobic physical activity," Sallis says.
But Sallis added that even a basic recommended level of exercise, "such as walking 30 minutes a day, five days a week is enough to help your body to fight off a variety of disease, including Covid-19."
Researchers of the study are recommending efforts to promote physical activity be prioritized by public health agencies and incorporated into routine medical care
Another study published by the National Institutes of Health in June linked regular exercise to a boost in immune-system response, which could serve as a tool in helping fight Covid-19, researchers said.
However the intensity of exercise could matter, according to another study published in March, which found that slow walkers were almost four times more likely to die from Covid than brisk walkers. The study looked at over 400,000 middle-aged adults in the U.K.
"We know already that obesity and frailty are key risk factors for COVID-19 outcomes. This is the first study to show that slow walkers have a much higher risk of contracting severe COVID-19 outcomes, irrespective of their weight," lead researcher and professor of physical activity and sedentary behaviour at the University of Leicester Tom Yates said in a press release.