SARS-CoV2 mainly affects the airways, and the effects of this virus on the respiratory system are described in different evaluation methods. Among them, there is Impulse Oscillometry (IOS), which can identify changes even when spirometry, a most common used method of evaluation, does not indicate them in post-COVID19 patients (Lopez et al.,2021).

To analyse the mechanical properties of the airways by Impulse Oscillometry (IOS) before and after submaximal exercise in individuals affected by the mild and severe form of COVID-19.

Descriptive observational study of post-COVID-19 patients with mild and severe, stable form. The airway evaluation was measured by Jaeger IOS (Jaeger, Wurzburg, Germany, software Launch SentrySuiteTM version 2.11) before and after submaximal exercise. Variables analysed: R5 and 20Hz (R5, R20 and R5-R20) resistance , 5Hz (X5) reactance, reactance area (AX) and resonance frequency (Fres), absolute values (kPa/L/s) and % of predicted.

36 individuals were included, age 46.92(12.23)years, height 176(8.43)cm, weight 90.4 (22.56)kg and BMI 30.09(6.97)kg/m2. When compared, the pre vs. post-exercise values showed no difference for the whole group [(R5% 128(0.35) x 121(0.30)] and mild group [(R5% 129(0.32) x 124(0.18)], for all variables. However, for the severe group, physical exercise induced a significant difference for R5%: 127(0.38) x 118(0.37), R20: 0.32(0.07) x 0.30(0.07), X5: -0.13(0.02) x -0.11(0.05) e AX: 0.72(0.20) x 0.59(0.51) (p<0.05).

Submaximal exercise leads to a decrease in total and central resistance, in addition to the improvement of elastic capacitance in patients with the severe form of COVID-19.