Physical Activity and the Risk of COVID-19 Infection and Mortality: A Nationwide Population-Based Case-Control Study

Abstract

Regular physical activity (PA) is known to reduce the risk of serious community-acquired infections. We examined the association of PA with the morbidity and mortality resulting from coronavirus disease (COVID-19) infection in the South Korean population. Patients who tested positive for severe acute respiratory coronavirus 2 and who underwent public health screening between 2014 and 2017 (n = 6288) were included. Age- and sex-matched controls (n = 125,772) were randomly selected from the Korean National Health Insurance Service database. Leisure-time PA was assessed using a self-reported questionnaire. The mean PA levels were lower in the patient than in the control group (558.2 ± 516.3 vs. 580.2 ± 525.7 metabolic equivalent of task (MET)-min/week, p = 0.001). Patients with moderate to vigorous PA (MVPA) were associated with a lower risk of COVID-19 morbidity (odds ratio (OR), 0.90; 95% confidence interval (CI), 0.86–0.95). In addition, a standard deviation (SD) increment in MET/week (525.3 MET-min/week) was associated with a 4% decrease in the risk of COVID-19 morbidity (OR, 0.96; 95% CI, 0.93–0.99). MVPA and an SD increment in MET/week were associated with lower mortality (MVPA: OR, 0.47; 95% CI, 0.26–0.87; per SD increment: OR, 0.65; 95% CI, 0.48–0.88). Higher levels of regular PA were associated with a lower risk of COVID-19 infection and mortality, highlighting the importance of maintaining appropriate levels of PA along with social distancing amid the COVID-19 pandemic.

Metabolically unhealthy individuals, either with obesity or not, have a higher risk of critical coronavirus disease 2019 outcomes than metabolically healthy individuals without obesity

“…All patients were followed up until 4 months after the diagnosis of COVID-19 or until death. A more detailed protocol has been previously published [ 17 ]. We presented the STORBE checklist in Supplementary Table S1.…”

Moderate exercise may prevent the development of severe forms of COVID-19, whereas high-intensity exercise may result in the opposite

“…A higher percentage (50%) of the decrease of the risk of hospitalization in case of SARS-CoV-2 infection was found by Sallis et al (2021) - [20] , the association being valid for a moderate to strenuous effort intensity and for physical activity performed by the patient in the last 2 years before illness [20] . For the same intensity of effort (established by a questionnaire method in patients infected with the virus), Korean researchers found a 10% decrease in the risk of infection and a 53% decrease in mortality, independent of confounding factors [21] . The online completion of a questionnaire about the level of physical activity and severity of COVID-19 by participants previously infected with SARS-CoV-2 revealed that the possibility of hospitalization decreases by 64% in those able to maintain a brisk walk (thus moderate effort) [22] .…”

“…Yet, there is no upper limit on the intensity of effort for exercises used to prevent severe forms of COVID-19. There may be a temptation to increase the body's stress, given that a standard deviation increment in MET/week (525.3 MET-min/week) was associated with a 4% decrease in the risk of COVID-19 morbidity [21] .…”

Kinesiology in the 4th Industrial Revolution and Pandemic Era

“…The higher the physical activity and the better the cardiopulmonary function, the lower the possibility of infection with COVID-19 and the lower the mortality rate [4]. Therefore, the importance of regular physical activity and exercise programs for improving physical fitness based on sport science and Kinesiology is being emphasized.…”