Assessment of exertional capacity and quality of life in COVID-19 survivors

<bold>Objective:</bold> Many COVID-19 survivors maintain symptoms, impaired exercise capacity, and quality of life. We aimed to analyze exertional capacity using the six-minute step test (6MST) and quality of life in COVID-19 survivors. <bold>Methods:</bold> A prospective observational study with COVID-19 survivors 6 months post-hospitalization at an infectious diseases center in Paraiba, Brazil, between April and December of 2020. Participants underwent face-to-face interviews, medical examinations, mMRC and SF-12 questionnaires, spirometry, 6MST, and chest computed tomography. <bold>Results:</bold> 100 patients were eligible, responded to the SF-12 questionnaire, and 88 performed the 6MST. The mean number of steps climbed during the test was 132.8 ± 30.9, and the mean heart rate predicted was 84.6% ± 13.5. Lower exertion capacity was observed in 37.8% of survivors compared to the normative values of the Brazilian healthy population. The SF-12 revealed a reduction in physical health (PCS median 44.03), but normal mental health (MCS median 52.8). In the final linear multi variable model, sex (p<0.001), dyspnea mMRC post-COVID (p 0.02), MCS-12 (p 0.002), and age (p<0.001) remained as associated predictors with the number of steps climbed on the 6MST. After logistic regression, female sex (p 0.002) was the only predictor associated with PCS and MCS scores. <bold>Conclusions:</bold> The 6MST was feasible and often revealed submaximal exercise capacity in assessing COVID-19 survivors. This sample exhibited lower exertion performance than the healthy population, representing the most compromised component of their quality of life. Notably, this decrease in health quality was more pronounced in females, aligning with findings from other post-COVID studies.