Exercise is Medicine for COVID-19

A retrospective observational study from Kaiser Permanente shows that those who consistently met physical activity guidelines before their COVID-19 diagnosis were about 2.5 times less likely to die.

Disclaimer: Since writing, the Centers for Disease Control and Prevention (CDC) has added physical inactivity to its list of underlying medical conditions that put people ages 18 years and older at higher risk for severe illness from the virus that causes COVID-19.

The COVID-19 pandemic has dominated nearly every aspect of our lives during the past year and a half. Early on, studies showed the elderly and patients who suffer from non-communicable diseases (NCDs) were at the highest risk for severe COVID-19 outcomes, defined as being hospitalized, admitted to the intensive care unit (ICU), and dying.

Yet, we know that regular exercise can significantly reduce the incidence and improve the management of NCDs and enhanced immune function.

As a long-time family medicine physician, I have observed firsthand the benefits of exercise to the health and well-being of my patients. In fact, with virtually every disease I encounter in my practice, I have found that exercise is the most powerful medication I can prescribe. For that reason, I felt it was likely that regular exercise would dramatically reduce the risk of severe COVID-19 outcomes.

Testing the Theory: Exercise Reduces Risk of Severe COVID

I led a group of colleagues in a study to test the hypothesis that consistently meeting physical activity (PA) guidelines (>150 minutes per week of moderate to vigorous PA) prior to a diagnosis of COVID-19 would lead to more favorable outcomes among adults. The study, published in the April issue of the British Journal of Sports Medicine, was conducted at Kaiser Permanente in Southern California, an integrated healthcare system serving some 4.7 million residents at 15 medical centers.

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The exercise habits for all Kaiser patients are assessed at every outpatient visit using an Exercise Vital Sign (EVS). The medical assistant assesses the EVS by asking each patient two questions about their exercise habits during the intake at each outpatient visit:

  1. On average, how many days a week do you engage in moderate to vigorous exercise like a brisk walk?

  2. On average, how many minutes per day do you exercise at this level?

The electronic medical record then multiplies the responses to find the total minutes per week of self-reported moderate or more intense exercise.

Our analytic cohort consisted of 48,440 COVID-19 patients with a mean age of 47.5 years—62% were female, and 65% were Hispanic. Mean BMI was 31.2 kg/m2, and almost half the patients had at least one comorbidity. In terms of COVID-19 outcomes, 8.6% of patients were hospitalized, 2.4% were admitted to the ICU, and 1.6% died.

Physically Active People Reduce Severe COVID Risk

With unadjusted data, we found that patients who were consistently meeting PA guidelines prior to their COVID-19 diagnosis were about 70% less likely to be hospitalized and about 80% less likely to die than those who lacked physically active lifestyles.

After adjusting for the Centers for Disease Control and Prevention (CDC)-defined risk factors for severe COVID-19, those who were consistently meeting PA guidelines prior to their COVID-19 diagnosis were 2.26 times less likely to be admitted to the hospital and almost 2.5 times less likely to die compared to inactive patients. The only more significant risk factors were older age (>60) and a history of organ transplant.

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We also found that patients who were doing just “some activity” (>10 min but <150 minutes per week) were also at a lower risk of both hospitalization and death than those who were consistently inactive. Interestingly, race and obesity—unless severe (BMI >40 kg/m2)—did not change the risk for severe COVID-19 after controlling for PA and other COVID-19 risk factors.

The strengths of our study were the large sample of COVID-19 patients who had a measure of their PA habits before diagnosis. Also, the COVID-19 risk factors and outcomes in our study population were objectively measured, having been taken directly from each patient’s electronic medical record. Limitations of the study included the fact that PA was self-reported using the EVS. However, Kaiser has used the EVS for over 10 years, and previous studies have validated its accuracy.

Public Health Officials Should Prioritize Exercise as Medicine

In my opinion, the evidence for the benefit of regular PA in terms of COVID-19 outcomes shown in our study dramatically contrasts with public health efforts to promote PA during the pandemic. We should be informing the public that short of vaccination, regular PA activity is likely the most important thing one can do to reduce their risk for severe COVID-19.

The results of this study define a clear and actionable guideline to decrease the risk for severe COVID-19 outcomes and suggest that PA should be prioritized by public health officials and incorporated into routine medical care. We all know that exercise is medicine, and we can now add COVID-19 to the long list of conditions an exercise prescription can treat!

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Robert Sallis

Robert Sallis, M.D., FAAFP, FACSM, is a Family Medicine and Sports Medicine physician at Kaiser Permanente Medical Center in Fontana, CA. He is Director of the Kaiser Sports Medicine Fellowship Training program and on the Administrative Faculty for the Family Medicine Residency. He is a Clinical Professor of Family Medicine at UC Riverside School of Medicine and serves as Chief Medical Officer for the Los Angeles Football Club. He is a former President of the American College of Sports Medicine and founded the “Exercise is Medicine” global health initiative during his term.