Impact of Post‐COVID Syndrome on Cardiorespiratory Fitness, Psychological Well‐Being, and Quality of Life in Adolescents: A Cross‐Sectional Study

BACKGROUND: Post-COVID syndrome (PCS) in adolescents, marked by persistent symptoms such as dyspnea and fatigue, remains poorly understood, particularly in those referred for exercise intolerance. OBJECTIVE: The objective of this study is to describe the clinical presentation and cardiorespiratory fitness (CRF) of adolescents with PCS and identify factors distinguishing those with normal versus reduced CRF. STUDY DESIGN: In this cross-sectional study, 31 adolescents (90% female) with PCS underwent cardiopulmonary exercise testing (CPET), pulmonary function tests, and completed validated questionnaires assessing fatigue, depression, hyperventilation, physical activity, and quality of life (QoL). Patients were grouped by CRF status and compared. RESULTS: Symptoms were more prevalent than in general PCS literature, likely due to referral bias. Moderate depression risk was present in 35%, and 75% reported QoL impairment comparable with chronic conditions. Nearly half (48%) had reduced CRF. CRF was not associated with acute infection severity but correlated with orthostatism, reduced O₂ pulse, and increased static air trapping (p < 0.05). Preinfection physical activity was positively associated with CRF (p = 0.014), whereas postinfection activity levels were similar across groups. CONCLUSION: PCS significantly impacts CRF, QoL, and psychological well-being in adolescents with exercise intolerance. Reduced CRF appears multifactorial, involving autonomic dysfunction, pulmonary limitations, and deconditioning. These findings underscore the need for comprehensive evaluation and targeted management strategies in this vulnerable population.