Abstract: Journal of Clinical Medicine Article Physical Activity and the Risk of COVID-19 Infection and Mortality: A Nationwide Population-Based Case-Control Study Dong-Hyuk Cho 1,† , Sun Ju Lee 2,† , Sae Young Jae 3 , Woo Joo Kim 4 , Seong Jun Ha 2 , Jun Gyo Gwon 5 , Jimi Choi 6 , Dong Wook Kim 2, * and Jang Young Kim 1, * 1 2 3 4 5 6 * †



 Citation: Cho, D.-H.; Lee, S.J.; Jae, S.Y.; Kim, W.J.; Ha, S.J.; Gwon, J.G.; Choi, J.; Kim, D.W.; Kim, J.Y. Physical Activity and the Risk of COVID-19 Infection and Mortality: A Nationwide Population-Based Case-Control Study. J. Clin. Med. 2021, 10, 1539. https://doi.org/ 10.3390/jcm10071539 Academic Editor: Jose-Manuel Ramos-Rincon Received: 23 February 2021 Accepted: 2 April 2021 Published: 6 April 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in Division of Cardiology, Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju 26426, Korea; why012@yonsei.ac.kr Department of Big Data Strategy, National Health Insurance Service, Wonju 26464, Korea; ju6801@nhis.or.kr (S.J.L.); haagoon@nhis.or.kr (S.J.H.) Department of Sport Science, University of Seoul, Seoul 02504, Korea; syjae@uos.ac.kr Division of Infectious Disease, Department of Internal Medicine, Korea University College of Medicine, Seoul 02841, Korea; wjkim@korea.ac.kr Division of Transplantation and Vascular Surgery, Department of Surgery, Korea University College of Medicine, Seoul 02841, Korea; doctorgjg@gmail.com Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul 02841, Korea; jjimchoi@gmail.com Correspondence: kimdw2269@gmail.com (D.W.K.); kimjang713@gmail.com (J.Y.K.); Tel.: +82-33-741-0916 (J.Y.K.) D.-H.C. and S.J.L. contributed equally to this work. 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. Keywords: severe acute respiratory coronavirus 2; COVID-19; physical activity; mortality published maps and institutional affiliations. 1...