Public health has preached a lot of things in the three years of the COVID-19 pandemic. It has promoted social distancing, masks, vaccines, and quarantine to help prevent the spread. And it has helped spread awareness about antivirals for people infected with COVID-19. 
But what about “social fitnessing”?
This is the premise that the more physically active a population is, the less chance of hospitalization and death from something like COVID-19. And promoting it population-wide as a public health strategy would seem to make sense. In fact, a pair of studies from Kaiser Permanente lends credibility to this idea.
Physical activity and COVID-19 severity
A 2021 study by Dr. Robert Sallis and colleagues of nearly 49,000 patients with COVID-19 showed a dramatic 2-fold increase in hospitalization (OR 2.26), ICU admission (OR 1.73) and death (OR 2.46) between those who were “consistently inactive” and those getting the recommended amount of daily exercise. The authors concluded, “We recommend efforts to promote physical activity be prioritized by public health agencies and incorporated into routine medical care.”
Does this relationship hold true for those with chronic health conditions and across age, sex, race and ethnic population subgroups? In the case of chronic conditions, it could be that exercise simply is not effective at mitigating risks. And given the significant sociodemographic inequities seen in the pandemic, it is important to know if the COVID-protective benefit of physical activity applies to all groups equally.
Would social fitnessing benefit everyone equally?
A second study published by Dr. Deborah Rohm Young and colleagues in 2022 examined nearly 195,000 Kaiser Permanente COVID-19 cases to answer both questions. Overall, the dose-response effects of physical activity were similar to the first study for hospitalization, deterioration and death.
For instance, when looking at the odds ratio for death, using “always active” as the control group, the odds ratio for death was as follows: consistently active (OR 1.55), some activity (OR 1.92), mostly inactive (OR 2.88), and always inactive (OR 3.91). The study controlled for age, sex, race, ethnicity, BMI, ever smoker, hospital utilization, HbA1c, comorbidities, Medicaid status, and vaccination status before COVID diagnosis.
Importantly, these dose-response effects held for those with cardiovascular disease and hypertension, and also extended across sex, race, ethnicity, age and BMI. The authors made a similar plea as the UK study: “Public health leaders should add physical activity to pandemic control strategies.”
Interpreting these data as a family physician
As a family physician who spends a lot of my time working to get people moving, the data affirms the importance of this work that even I had not fully appreciated. In fact, I may have provided more benefit during the pandemic through our Running Medicine program than I had through providing hospital or clinic-based care to treat and prevent COVID-19.
I believe that movement heals on many levels – mind, body, spirit, and social. As I work to break down barriers to physical activity, two pieces of data from the studies stand out.
First, 58% of all the patients were in the lowest two categories of physical activity (always or mostly inactive). Only 20% were in the highest two categories (consistently or always active). What might COVID-19 have looked like in the U.S. if these two numbers were reversed? And how can we work on a population level to make that happen?
Second, I’m struck by the differences in physical activity across racial categories. Whites were less likely be in the lowest two physical activity categories (54.4%) than either Hispanics (59.5%) or Blacks (61.5%). We know that access to physical activity is not evenly distributed across populations. The reasons are myriad, including time and expense involved, local infrastructure, and safety issues. In the context of COVID-19, the physical activity inequities likely contributed to the inequities in COVID-19 morbidity and mortality.
Move lots, every day, if you want to keep death away
We need to do more as health leaders to make physical activity accessible for all communities. With its Active People, Healthy Nation campaign, the Centers for Disease Control and Prevention offers proven strategies to increase community physical activity. These range, for example, from increasing activity-friendly routes to everyday destinations to using signage to prompt more physical activity.
In closing, I will invoke Michael Pollan who attempted to put all we know about food and health in a simple saying, “Eat food, mostly plants, not too much.” Perhaps the complement for social fitnessing and health (even, or especially, during a pandemic) would go as follows: “Move lots, every day, if you want to keep death away.”
