AbstractPurposeThis small-scale, prospective cohort study nested within a randomized controlled trial aimed to investigate the possible associations between physical activity levels and clinical outcomes among hospitalized patients with severe COVID-19.MethodsHospitalized patients with severe COVID-19 were recruited from Clinical Hospital of the School of Medicine of the University of Sao Paulo (a quaternary referral teaching hospital), and from Ibirapuera Field Hospital, both located in Sao Paulo, Brazil. Physical activity levels were assessed by Baecke Questionnaire of Habitual Physical Activity. The primary outcome was hospital length of stay. The secondary outcomes were: mortality, admission to the intensive care unit (ICU), and mechanical ventilation requirement.ResultsMean hospital length of stay was 8.5 ± 7.1 days; 3.3% of patients died, 13.8% were admitted to ICU, and 8.6% required mechanical ventilation. Linear regression models showed that physical activity indexes were not associated with hospital length of stay (work index: β=-0.57 [95%CI: −1.80 to 0.65], p=0.355; sport index: β=0.43 [95%CI: −0.94 to 1.80], p=0.536; leisure-time index: β=1.18 [95%CI: −0.22 to 2.59], p=0.099; total activity index: β=0.20 [95%CI: −0.48 to 0.87], p=0.563. Physical activity indexes were not associated with mortality, admission to ICU and mechanical ventilation requirement (all p>0.05).ConclusionsAmong hospitalized patients with COVID-19, physical activity did not associate with hospital length of stay or any other clinically-relevant outcomes. These findings suggest that previous physical activity levels may not change the prognosis of severe COVID-19.