Patients who survive COVID-19 may experience manifestations after the acute phase of the disease. This condition is known as "long COVID syndrome" and can occur due to complications from hospitalization, sequelae from the acute phase, and other related mechanisms. Patients who are hospitalized, both active and sedentary, may experience loss of muscle mass, including the respiratory muscles. It is known that active individuals have values of Maximal Inspiratory Pressure (MIP) above the population average, which can minimize the damage of muscle loss during hospitalization.

To verify if the level of physical activity prior to hospitalization has an impact on the inspiratory muscle strength of patients with long-term COVID-19.

This is a retrospective study based on a database of a rehabilitation project for patients with long-term COVID-19. The sample consisted of adults from the Midwest region in Brazil diagnosed with COVID-19 who presented persistent symptoms for at least 4 weeks after the onset of symptoms. The patients considering the physical activity were classified as sedentary, irregularly active, and active. MIP was obtained through manovacuometry according to the protocols of the European Respiratory Society/American Thoracic Society. The values obtained were compared with those predicted by Pessoa et al. Normality was evaluated by the Shapiro-Wilk test. The Kruskal-Wallis test was used to assess the difference between the median of the physical activity level groups.

Data from 47 patients were evaluated, with 59.6% female (n=28), mean age of 54.3±10.9 years, weight of 82.2±14.9 kg, height of 163.8±9.3 cm, and 24.2±18.7 days of hospitalization. 63.8% (n=30) of patients were sedentary, 17.0% (n=8) were irregularly active, and 19.1% (n=9) were physically active. The mean MIP obtained was 76.7±25.6 (85.0±28.5% of predicted). There was no difference between the groups in the MIP obtained (p= 0.80) and in the percentage of predicted (p=0.90).

The level of physical activity prior to hospitalization did not impact the respiratory muscle strength of patients with long-term COVID-19. Other factors, such as the number of days hospitalized and physiotherapeutic intervention during hospitalization, have an impact on the maintenance or loss of respiratory muscle strength. As a limitation of the study, the number of days for evaluation after the initial infection is highlighted.

This analysis reinforces the need to prescribe respiratory muscle training in the hospital environment for all patients, regardless of ess of their prior physical activity history.