A lot of the talk about preexisting conditions as they relate to COVID-19 has centered on diseases like obesity, diabetes, hypertension, cardiovascular disease and cancer, as well as on poor habits like smoking. Largely absent from this conversation has been physical inactivity.
Recent research published in the British Journal of Sports Medicine investigated the role that physical inactivity plays in severe COVID-19 outcomes, including death, and found that being consistently inactive was a stronger risk factor than any of the aforementioned medical conditions and behaviors. In fact, the only risk factors with a stronger association with severe outcomes were advanced age and a history of organ transplant.
Notably, while meeting the Physical Activity Guidelines for Americans and WHO Guidelines on Physical Activity and Sedentary Behavior recommendation of performing 150 minutes or more of cardiorespiratory activity was associated with the most substantial benefits, those individuals performing physical activity below that threshold still had a lower risk for severe COVID-19 outcomes than those who were consistently inactive. As is typically the case, more exercise is best, but some exercise is better than none.
A Deeper Look
The research team wanted to explore the potential impact of physical inactivity on the severity of infection among those who contracted COVID-19, including hospital admission rates, the need for intensive care, and death. They compared these outcomes in more than 48,000 adults who caught COVID-19 between January 2020 and October 2020.
All of these individuals had reported their level of regular physical activity on multiple occasions at outpatient clinics between March 2018 and March 2020 and were classified into three categories:
- Consistently inactive (0–10 minutes/week) – 15% of individuals
- Some activity (11–149 minutes/week) – 78% of individuals
- Consistently meeting physical activity guidelines (150+ minutes/week) – 7% of individuals
The average age of these individuals was 47 years old and 62% were women. Their average body mass index of 31 kg/m2 classified them as obese. About half had no underlying conditions (e.g., diabetes, chronic obstructive pulmonary disease, cardiovascular disease, kidney disease and cancer); nearly one in five had one underlying condition; and almost a third had two or more.
Approximately 9% of the more than 48,000 individuals were admitted to the hospital, around 3% required intensive care and tragically 2% died from COVID-19.
After taking into account potentially influential factors like race, age and underlying conditions, the researchers found that individuals who were consistently physically inactive were more than twice as likely to be admitted to a hospital, 73% more likely to require intensive care and 2.5 times more likely to die than those individuals who met physical activity guidelines.
Importantly, those in the “some activity” category—the vast majority of individuals—were far better off than those who were consistently inactive. When compare to this group, consistently inactive individuals were 20% more likely to be admitted to the hospital, 10% more likely to require intensive care and 32% more likely to die of the disease.
Notably, this is an observational study and therefore cannot establish cause. In addition, the researchers were relying on patients’ own assessments of their physical activity levels, and there was no measure of intensity beyond the threshold of “moderate to strenuous exercise,” such as a brisk walk.
That said, this was a large and ethnically diverse population of people, and the finding that being consistently inactive was a stronger risk factor for severe outcomes than any of the commonly cited medical conditions and risk factors is vital to our understanding of the disease, not to mention our ability to prepare for, and respond to, future pandemics.
The research team recommended that efforts to promote physical activity be prioritized by public health agencies and incorporated into routine medical care. Physical activity should also be included in public health safety guidelines alongside getting vaccinated, practicing social distancing, and wearing masks. By combining these behaviors, individuals will be best positioned to not only avoid catching COVID-19, but also prevent severe outcomes, including death, should they contract the disease.