Study Finds Inactivity a Key Risk Factor for Severe COVID-19

Physical activity has beneficial effects on several physiological systems associated with COVID-19 and can also benefit immune health, metabolic health, and mental health. Evidence over the past year has found associations between physical inactivity and other lifestyle factors and odds of severe COVID-19.

Specifically, there’s a link between physical activity and COVID-19 outcomes. Early in the pandemic, researchers in the U.K. found unhealthy lifestyles, including physical inactivity, elevated the risk of COVID-19 hospitalization. Another study at the Henry Ford Health System found that odds of hospitalization from COVID-19 were over three times higher among people with the lowest compared to the highest peak exercise capacity.

Today, a new study was announced by The BMJ, finding that physical inactivity is a key risk factor for severe COVID-19 outcomes, including:

• hospitalization,
• intensive care unit (ICU) admission, and
• death.

The study analyzed data on 48,440 adult patients at Kaiser Permanente who had COVID-19 between January 1, 2020, and October 21, 2020, and had at least two or more Exercise Vital Sign measurements in their health records between March 2018 - March 2020.

Exercise Vital Sign is a measurement of physical activity included in patient health records at Kaiser Permanente Southern California since 2009. The vital sign consists of a patient's weekly frequency and duration of moderate to strenuous exercise and are included in patient health records. Based on vital sign measurements, 6.4% of patients in the study were consistently active, 14.4% were consistently inactive, and the remaining 79.2% were inconsistently active.

Key Findings

1. Physical inactivity is strongly associated with COVID-19 outcomes, and physical activity provides significant protection from severe outcomes including hospitalization, ICU admission, and death.
2. Being consistently inactive more than doubled odds of hospitalization compared to being consistently active. Odds of ICU admission were 1.73 times higher and odds of death 2.49 times higher for the consistently inactive.
3. Aside from being over age 60 and a history of solid organ transplant, consistent physical inactivity was the most significant risk factor for COVID-19 death.
4. While meeting the U.S. Physical Activity Guidelines was associated with the most significant benefits, even those doing some physical activity were at lower risk for severe COVID-19 outcomes, including death, than people who remained consistently inactive.

One of the study’s lead researchers and IHRSA Medical, Science, and Health Advisory Council member, Robert Sallis, M.D., said, “This is a wake-up call for the importance of healthy lifestyles and especially physical activity. Kaiser Permanente’s motivation is to keep people healthy, and this study truly shows how important that is during this pandemic and beyond. People who regularly exercise had the best chance of beating COVID-19, while people who were inactive did much worse.”

See the full press release from Kaiser Permanente.

Implications for the Fitness Industry

This study’s findings would appear to point to physical inactivity as the most significant modifiable risk factor for COVID-19 severity. Furthermore, physical inactivity is a risk factor that can be improved on a shorter timeline and can be more accessible than other risk factors, such as losing weight or reversing chronic health conditions.

Given the importance of physical activity for physical and mental health and the risk posed by physical inactivity for severe COVID-19, policymakers should prioritize physical activity in the ensuing months of recovery and reopening.

In their 2020 Guidelines on Physical Activity and Sedentary Behavior, the World Health Organization (WHO) recommends a “whole system” approach of “policies and multiple actions that can, through engagement of a wide range of stakeholders, support more people to be physically active across multiple sectors and settings. Using a ‘systems’ approach that is aligned with a sustained communication strategy ensures that increased demand for physical activity, generated through effective communication, is matched by the provision of environments and opportunities for people to be physically active.”

Governments and communities should also invest more in disability inclusion initiatives to create more opportunities for participating in exercise and sport, especially among groups who have been disproportionately affected by COVID-19 or COVID-19-related restrictions. A more collaborative relationship between the medical and allied health communities and physical activity and fitness providers would help make physical activity more accessible and achievable for more people with chronic disease and disabilities.