Exercise reduces COVID-19 severity risk

By Pooja Toshniwal PahariaReviewed by Benedette Cuffari, M.Sc.Dec 19 2022

In a recent study published in the American Journal of Preventive Medicine, researchers investigate the association between physical activity and coronavirus disease 2019 (COVID-19) severity outcomes among demographically diverse individuals suffering or not suffering from chronic medical conditions in a dose-response manner.

Study: Associations of Physical Inactivity and COVID-19 Outcomes Among Subgroups. Image Credit: ViDl Studio / Shutterstock.com

Background

Physical activity prior to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection diagnosis has been associated with improved COVID-19 outcomes among individuals with chronic clinical conditions.

However, the amount of physical exercise required to protect against COVID-19 severity outcomes remains unclear. Moreover, data on the protective effects of physical activity against SARS-CoV-2 infection among individuals without any underlying chronic medical condition are limited.  

It is essential to characterize the benefit of physical exercise against COVID-19 severity by demographic parameters such as sex, race, age, and ethnicity to guide policy-making and tailor healthcare strategy development for effective COVID-19 mitigation.

About the study

In the present retrospective cohort study, researchers evaluate the dose-response association between physical activity and SARS-CoV-2 infection outcomes by patient demographics and the absence or presence of underlying chronic medical conditions.

The study comprised Kaiser Permanente Southern California (KPSC) adults diagnosed with COVID-19 between January 1, 2020, and May 31, 2021, whose electronic health record (EHR) data were analyzed. The study exposure was the median of three or more self-documented physical activity reports before the SARS-CoV-2 infection diagnosis among individuals who were continuously enrolled in the KPSC system for less than or equal to six months prior to the diagnosis.

The team excluded hospitalized SARS-CoV-2-positive pregnant women whose delivery was scheduled during the period of the study. The study outcomes included hospital admission, deteriorating events, or death after 90 days of SARS-CoV-2 infection diagnosis.

Data were analyzed in 2022. Physical exercise levels were evaluated based on the exercise vital sign (EVS) scores. In addition, patients were asked to document the number of days and duration of engagement in moderate or strenuous physical activity per week.

Based on the answers, the study participants were divided into the following groups:

• Consistently physically inactive (≥3.0 EVS assessments at ≤10.0 minutes weekly)
• Mostly physically inactive (≥1.0 EVS assessment for more than 19 minutes weekly, or a median of 60 or fewer minutes weekly)
• Some physical exercise with median EVS values between 60 and 150 minutes weekly
• Consistently physically active (≥1 EVS less than 150 minutes weekly or a median exceeding 150 minutes weekly)
• Always physically active (≥3 EVS assessments exceeding 150 minutes weekly)

COVID-19-associated hospital admissions included those reported within three weeks of diagnosis at KPSC hospitals. Deterioration events required intense respiratory care and/or intensive care unit (ICU) admission.

Chronic medical conditions included those related to adverse SARS-CoV-2 infection outcomes, according to the United States Centers for Disease Control and Prevention (CDC), and were present prior to the infection. These included hypertension, cardiovascular diseases, diabetes, prior organ transplantations, cancer, and chronic obstructive pulmonary disease (COPD).  

Logistic regression modeling was performed, and odds ratios (ORs) were calculated.

Study findings

Out of 194,191 adult COVID-19 patients, 6% were admitted to hospitals, 3% developed deterioration events, and 3% died within 90 days of COVID-19 diagnosis. Among the participants, 61%, 21%, 7%, and 7% were Hispanics, Whites, Blacks, Pacific Islanders, or Asians, respectively.

More than 50% of the participants had body mass index (BMI) values equal to or greater than 30 kg/m². In addition, about 22% and 9% of individuals were diagnosed with hypertension and cardiovascular diseases, respectively.

Among the study participants, 15%, 43%, 22%, 14%, and 6% were divided into the always inactive and mostly inactive, with some activity, consistently active, and always active groups, respectively. Consistently active and always active individuals were likelier to be younger males with lower BMI values and no smoking habits.

Consistently inactive and mostly inactive individuals were more likely to be Black or Hispanic, have BMI values equal to or greater than 30 kg/m², and suffer from hypertension or cardiovascular diseases.

Individuals engaged in some physical activity groups had 43% greater odds of hospitalization (OR=1.4), 83% higher odds of deterioration events (OR 1.8), and 92% greater odds of deaths (OR=1.9) as compared to individuals in the always active category. Conversely, consistently inactive individuals had 91% higher hospitalization odds (OR 1.9), 139% higher deterioration event odds (OR=2.4), and 291%  higher death odds (OR=3.9) as compared to always active individuals.

The odds of hospitalization for individuals engaged in some physical activities were 31% greater for males (OR=1.3) and 84% greater for females (OR=1.8) than always active individuals, with an interaction indicating greater odds for women than for men across physical activity groups. In addition, even with some physical activity, hypertensive individuals had greater odds of death than always-active individuals (OR 1.9).

When comparing mostly physically inactive individuals with always active individuals, significant ORs were noted for cardiovascular disease patients, including those with congestive cardiac failure, myocardial infarction, cerebrovascular diseases, and peripheral vascular diseases (OR 2.4).

Strong dose-response effects were observed. These findings were usually consistent across age, BMI, sex, ethnicity, and race for hypertensive individuals and those with cardiovascular diseases.

The findings indicate that physical inactivity was associated with worse COVID-19 outcomes across clinical and demographic characteristics. Thus, public health authorities must incorporate physical activity into COVID-19 mitigation strategies.