Exercise-Based Rehabilitation in Severe COVID-19 Survivors with Long COVID: A Randomized Controlled Pilot Study

Introduction: Post-hospital rehabilitation is essential for survivors of severe COVID-19, as prolonged immobility and clinical severity often lead to muscle weakness, reduced cardiovascular capacity, and impaired respiratory function. Physical exercise during and after hospitalization may mitigate these effects and support functional recovery. This study aimed to evaluate the effectiveness of a physical exercise-based rehabilitation program in survivors of severe COVID-19. Methodology: A randomized clinical trial was conducted with 30 survivors allocated to two groups: multicomponent exercise (GEm) and multicomponent exercise combined with inspiratory muscle training (GEmTMI). The interventions were performed three times per week for 40–60 min. Quality of life, physical activity level, functional status, and physical capacity were assessed before and after six weeks. Results: Comparisons between GEm and GEmTMI showed significant differences in the 6 min walk test (6MWT) at baseline (p = 0.043) and in the Physical Activity Index (IPAQ) after the intervention (p = 0.002). When the total sample was analyzed, significant improvements were observed across all outcomes after rehabilitation, including quality of life (SF-36), functional capacity (PCFS), physical activity level (IPAQ), respiratory muscle strength, and additional functional tests. Notable improvements included SF-36 Physical Functioning (p = 0.006) and Social Functioning (p = 0.009), PCFS (p = 0.011), IPAQ (p = 0.012), and performance in the 6MWT, STS, STS-1min, TUG, handgrip strength, PEmax, and PImax (all p < 0.001). Discussion: Multicomponent physical rehabilitation, with or without inspiratory muscle training, produced significant gains in physical activity level, functional capacity, dynamic balance, neuromuscular fitness, respiratory muscle strength, and quality of life. These findings underscore the importance of structured post-ICU rehabilitation to support comprehensive physical and psychosocial recovery in survivors of severe COVID-19.