Dissociation Between Peripheral Muscle Strength and Exercise Capacity in Symptomatic Post-COVID-19 Individuals:...

Infection with SARS-CoV-2 may result in persistent functional impairment after the acute phase of the disease. Emerging evidence suggests that the presence and intensity of COVID-19-related symptoms may be associated with deficits in muscle strength and physical performance during the post-infection period. Our objective was to compare physical performance after the acute phase of COVID-19 between symptomatic and asymptomatic individuals, focusing on exercise capacity and peripheral muscle strength.

This cross-sectional, prospective study included 76 adults aged 18-77 years, registered in the Brazilian Unified Health System. Participants were classified as symptomatic or asymptomatic based on clinical records. Physical activity level was assessed using the International Physical Activity Questionnaire (IPAQ). Physical performance was evaluated through handgrip strength and exercise capacity measured by the Incremental Shuttle Walking Test (ISWT). Multivariate analysis of covariance (MANOVA) and univariate analyses (ANCOVA) were performed, adjusted for age, sex, and physical activity level.

The presence of COVID-19-related symptoms was independently associated with lower handgrip strength (p = 0.0099) after adjustment for covariates. No significant differences were observed in exercise capacity between the symptomatic and asymptomatic groups (p = 0.497). Effect size analysis demonstrated a moderate association between symptom presence and peripheral muscle strength, whereas the association with exercise capacity was small.

Symptomatic individuals after COVID-19 exhibited reduced peripheral muscle strength despite no significant differences in exercise capacity between the groups. These findings underscore the relevance of handgrip strength assessment as a simple and sensitive tool for identifying residual functional impairment in post-COVID-19 follow-up.