Active Voice: Exercise is Medicine for COVID-19
By: Robert Sallis, M.D., FACSM

The COVID-19 pandemic has dominated nearly every aspect of our lives during the past 18 months. Early on, studies showed the elderly and patients who suffer from non-communicable diseases (NCDs) were at greatest risk for severe COVID-19 outcomes, defined as being hospitalized, admitted to the intensive care unit and dying. Yet we know that regular exercise has been shown to significantly reduce the incidence and improve the management of NCDs and enhance immune function.

As a long-time family medicine physician, I have observed firsthand the benefits of exercise for 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.

Therefore, 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 was conducted at Kaiser Permanente in Southern California, which is an integrated health care system serving some 4.7 million residents at 15 medical centers. All Kaiser patients have their exercise habits assessed at every outpatient visit using an Exercise Vital Sign (EVS). The EVS is assessed by the medical assistant who asks each patient two questions about their exercise habits (frequency and duration) during the intake at each outpatient visit.

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 body mass index was 31.2 kg/m2 and almost half the patients had at least one co-morbidity. In terms of their COVID-19 outcomes, 8.6% were hospitalized, 2.4% were admitted to the intensive care unit and 1.6% died. 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.

After adjusting for the 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 patients who were consistently inactive. The only bigger risk factors were older age (> 60 yrs.) and a history of organ transplant. We also found that patients who were doing just “some activity” (>10 mins. but <150 mins. per week) were also at a lower risk of both hospitalization and dying than those who are consistently inactive. Interestingly, race and obesity (unless severe [body mass index >40 kg/m2]) were not found to be risks 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 they were diagnosed. 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, the EVS has been in use at Kaiser for more than 10 years and has been validated in previous studies.

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 a vaccination, regular PA is perhaps 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 reduce 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 it should be prescribed to treat!

About the author:
Robert Sallis, M.D., FACSM, is a family medicine and sports medicine physician at Kaiser Permanente Medical Center in Fontana, California. He is director of the Kaiser Sports Medicine Fellowship Training program and on the administrative faculty for the Family Medicine Residency. Dr. Sallis also serves as a clinical professor of Family Medicine at UC Riverside School of Medicine and serves at chief medical officer for the Los Angeles Football Club (Major League Soccer). He is a past president of ACSM and founded the Exercise is Medicine® global health initiative during his term as ACSM president.

Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily represent positions or policies of ACSM. Active Voice authors who have received financial or other considerations from a commercial entity associated with their topic must disclose such relationships at the time they accept an invitation to write for SMB.