Introduction and Background: Symptoms persist for a long time, and there is a significant decrease in exercise capacity even in mild cases of post-COVID-19 syndrome. 

Objective: The study aimed to evaluate exercise capacity and functional balance in patients with post-COVID-19 syndrome compared to healthy controls and to determine the factors associated with these parameters.

Methods: The study included 20 patients with COVID-19 infection (mild-moderate) (mean age: 28.80±8.26 years, 17 F/3 M) and 20 age-gender-matched healthy controls with no COVID-19 infection. Functional limitation due to COVID-19 was determined using the Post-COVID Functional Status Scale (PCFS). The modified Charlson Comorbidity Index (CCI) scores were recorded. The dyspnea level and fatigue severity in daily life were evaluated with the modified Medical Research Council (mMRC) dyspnea scale and Fatigue Severity Scale (FSS), respectively. Quadriceps muscle strength (QMS) was measured, and exercise capacity was evaluated using the incremental shuttle walk test (ISWT). Functional balance was determined using timed up and go test (TUG).

Results: The mean time after infection was 37.50±12.33 weeks. The ISWT distance was significantly correlated with the CCI score (r=-0.554), mMRC score (r=-0.537), QMS (r=0.537), and TUG time (r=-0.564, p<0.05). The TUG time was also related to the CCI score (r=0.613), mMRC score (r=0.598), QMS (r=-0.558), and %QMS (r=-0.582, p<0.05) in patients with post-COVID-19 syndrome

Conclusion: Decrease in exercise capacity of individuals with post-COVID-19 syndrome is associated with increased perception of dyspnea, comorbidity level, muscle weakness, and balance in the long term.