Abstract: Original research Robert Sallis ‍ ‍,1 Deborah Rohm Young,2 Sara Y Tartof,2 James F Sallis,3 Jeevan Sall,1 Qiaowu Li,2 Gary N Smith,4 Deborah A Cohen2 ►► Additional supplemental material is published online only. To view, please visit the journal online (http://d​ x.​doi.​ org/1​ 0.​1136/b​ jsports-​2021-​ 104080). 1 Department of Family and Sports Medicine, Kaiser Permanente Medical Center, Fontana, California, USA 2 Research and Evaluation, Southern California Permanente Medical Group, Pasadena, California, USA 3 University of California San Diego, La Jolla, California, USA 4 Economics Department, Pomona College, Claremont, California, USA Correspondence to Dr Robert Sallis, Department of Family and Sports Medicine, Kaiser Permanente Medical Center, Fontana, CA 92335, USA; R​ obert.​E.S​ allis@​kp.​org Accepted 30 March 2021 Published Online First 13 April 2021 ABSTRACT Objectives To compare hospitalisation rates, intensive care unit (ICU) admissions and mortality for patients with COVID-19 who were consistently inactive, doing some activity or consistently meeting physical activity guidelines. Methods We identified 48 440 adult patients with a COVID-19 diagnosis from 1 January 2020 to 21 October 2020, with at least three exercise vital sign measurements from 19 March 2018 to 18 March 2020. We linked each patient’s self-­reported physical activity category (consistently inactive=0–10 min/ week, some activity=11–149 min/week, consistently meeting guidelines=150+ min/week) to the risk of hospitalisation, ICU admission and death after COVID-19 diagnosis. We conducted multivariable logistic regression controlling for demographics and known risk factors to assess whether inactivity was associated with COVID-19 outcomes. Results Patients with COVID-19 who were consistently inactive had a greater risk of hospitalisation (OR 2.26; 95% CI 1.81 to 2.83), admission to the ICU (OR 1.73; 95% CI 1.18 to 2.55) and death (OR 2.49; 95% CI 1.33 to 4.67) due to COVID-19 than patients who were consistently meeting physical activity guidelines. Patients who were consistently inactive also had a greater risk of hospitalisation (OR 1.20; 95% CI 1.10 to 1.32), admission to the ICU (OR 1.10; 95% CI 0.93 to 1.29) and death (OR 1.32; 95% CI 1.09 to 1.60) due to COVID-19 than patients who were doing some physical activity. Conclusions Consistently meeting physical activity guidelines was strongly associated with a reduced risk for severe COVID-19 outcomes among infected adults. We recommend efforts to promote physical activity be prioritised by public health agencies and incorporated into routine medical care.