The assessment of functional capacity in volunteers with post-covid syndrome has become an important issue to estimate functional consequences, disability and physiological responses to exercise. Our hypothesis is that patients show different cardiorespiratory responses to the 1-minute sit and stand test (1STS) according to the ventilatory support received in the acute phase of the disease.

To compare the initial cardiorespiratory responses by 1STS of patients from the "Post-covid life" study according to the ventilatory support received in the acute phase of the disease.

Cross-sectional observational study with post-covid volunteers with different severities of both sexes, adults, recruited between June 2020 to October 2022 to a Physiology Laboratory of UnB. For comparison the volunteers were divided into 3 groups according to the respiratory support received in the acute phase, being: no respiratory support (SSR), oxygen therapy (O2) and mechanical ventilation (MV). They were evaluated by 1STS according to the pre-established protocol, including recording heart rate, perception of effort before and after the test and number of repetitions performed. Statistical analyses were performed using the Statistical Package For The Social Sciences (SPSS), version 20. The Kolmogorov Smirnov test was used to evaluate the normality of the variables. The ANOVA test for unrepeated measures and the Kruskal Wallis test were used for intergroup comparisons, considering p<0.05 statistically significant. Registration number: NCT04595097.

We included 75 participants, 56% female, mean age 53.3±11.6 years, BMI 31.2±6.1 kg/m², hospitalization 20.1±17.8 days, 74% sedentary and 18% previously active. The number of repetitions was 21.3±9.4, 19.5±5.9 and 21.6±7.4 for SSR, O2 and MV groups respectively. The volunteers had a mean HR pre of 79.5± 11.0, 83.3± 12.6 and post of 85.6± 14.6, 92.2± 16.0, 101.3± 16.4 and 105.2± 18.7 beats for the SSR, O2 and MV groups. The pre-BORG of the SSR, O2, and MV groups were 9.1± 2.8, 9.7± 2.8, and 8.3± 8.0, and post 12.1± 3.3, 14.2± 2.6, and 13.0± 2.7. Although the number of repetitions showed no difference between groups (p>0.05), HR and BORG were higher in the MV group compared to the others (p<0.005).

Although the number of repetitions obtained by 1STS did not vary according to the ventilatory support received in the acute phase of COVID 19, the cardiorespiratory adjustments were greater in the volunteers submitted to MV compared to those who used O2 and SSR, suggesting greater deconditioning.

The results suggest that 1STS with HR monitoring and BORG is a functional test capable of assessing cardiorespiratory adjustments in post-covid patients.