Coronavirus Disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has resulted in millions of infections globally, with a significant proportion of survivors experiencing long-term pulmonary sequelae (1,2). Although the acute phase of COVID-19 primarily affects the respiratory system, emerging evidence highlights that even after clinical recovery, many patients continue to suffer from persistent respiratory dysfunction characterized by dyspnea, reduced lung volumes, and impaired exercise capacity (3,4). These post-acute sequelae, often termed "long COVID" or "post-COVID syndrome," pose a substantial burden on individuals’ physical, emotional, and social well-being (5).

Pulmonary rehabilitation (PR) is a comprehensive intervention based on individualized exercise training, education, and behavior change, designed to improve the physical and psychological condition of people with chronic respiratory disease and to promote long-term adherence to health-enhancing behaviors (6). PR has been extensively validated in patients with chronic obstructive pulmonary disease (COPD), interstitial lung disease, and other respiratory disorders, demonstrating significant benefits in improving dyspnea, exercise tolerance, and quality of life (7,8).

Given the similarities between the residual pulmonary impairments observed in COVID-19 survivors and other chronic respiratory conditions, PR has been proposed as a vital component of post-COVID-19 care strategies (9). However, prospective studies evaluating the structured implementation of PR programs specifically in post-COVID-19 patients are still limited. Early evidence suggests that targeted rehabilitation interventions may enhance pulmonary function, physical endurance, and overall quality of life, yet systematic evaluations are necessary to establish its efficacy conclusively (10).

This study was therefore designed as a prospective observational investigation to evaluate the impact of an 8-week structured pulmonary rehabilitation program on pulmonary function, exercise capacity, and health-related quality of life in patients recovering from COVID-19 who continue to experience respiratory dysfunction.

Study Design and Participants

Patients aged between 25 and 70 years, previously diagnosed with COVID-19 through RT-PCR, who continued to experience respiratory symptoms (such as dyspnea, reduced exercise tolerance, or abnormal pulmonary function tests) 12 weeks after recovery, were enrolled. Exclusion criteria included pre-existing chronic respiratory diseases (e.g., COPD, asthma), unstable cardiovascular conditions, psychiatric illnesses, or inability to participate in physical activity due to musculoskeletal limitations.

Pulmonary Rehabilitation Program

Participants underwent an 8-week structured pulmonary rehabilitation (PR) program. Sessions were conducted three times a week and included:

• Aerobic Exercise Training: Patients performed treadmill walking or stationary cycling at 60–80% of their maximum heart rate, gradually increasing exercise duration from 15 to 30 minutes per session.
• Breathing Retraining: Techniques such as diaphragmatic breathing and pursed-lip breathing were practiced to enhance ventilatory efficiency.
• Strength Training: Light resistance exercises focusing on major muscle groups were incorporated twice weekly.
• Education Sessions: Focused on energy conservation, respiratory hygiene, and management of breathlessness.
• Psychosocial Support: Group counseling and relaxation techniques were offered to address anxiety and depression related to post-COVID conditions.

All sessions were supervised by a multidisciplinary team comprising pulmonologists, physiotherapists, and psychologists.

Outcome Measures

Primary outcomes included changes in pulmonary function tests (PFTs), six-minute walk distance (6MWD), and health-related quality of life as assessed by the St. George’s Respiratory Questionnaire (SGRQ).

• Pulmonary Function Tests: Forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were measured using standardized spirometry equipment following ATS/ERS guidelines.
• Exercise Capacity: The 6MWD was conducted according to American Thoracic Society guidelines, with distance covered in meters recorded.
• Quality of Life: The validated SGRQ was administered to evaluate symptoms, activity limitations, and psychosocial impacts.

Assessments were performed at baseline and at the end of the 8-week rehabilitation program.

Statistical Analysis

Data were analyzed using SPSS version 26. Continuous variables were expressed as mean ± standard deviation (SD). Paired t-tests were used to compare pre- and post-rehabilitation outcomes. A p-value of less than 0.05 was considered statistically significant.

A total of 60 post-COVID-19 patients were enrolled in the study, out of which 55 (91.7%) completed the pulmonary rehabilitation (PR) program. The mean age of the participants was 52.3 ± 11.4 years, with 32 (58.2%) males and 23 (41.8%) females. Baseline characteristics of the study population are summarized in Table 1.

Pulmonary function showed significant improvement following the rehabilitation program. The mean forced vital capacity (FVC) increased from 62.5 ± 9.8% predicted at baseline to 74.3 ± 8.7% post-rehabilitation (p < 0.001), and forced expiratory volume in 1 second (FEV1) improved from 64.2 ± 10.1% to 76.5 ± 9.3% predicted (p < 0.001) (Table 2).

Exercise capacity also showed notable enhancement, with the mean six-minute walk distance (6MWD) increasing from 320.6 ± 54.2 meters at baseline to 405.7 ± 48.9 meters post-program (p < 0.001) (Table 3).

Health-related quality of life, as assessed by the St. George’s Respiratory Questionnaire (SGRQ), demonstrated substantial improvement. The total SGRQ score decreased from 58.2 ± 10.1 at baseline to 41.6 ± 9.5 after completing the PR program (p < 0.001), with significant reductions observed in symptom, activity, and impact domains (Table 4).

No adverse events or major complications were reported during the course of the rehabilitation sessions.

Table 1: Baseline Characteristics of the Study Population (n=55)

Table 2: Pulmonary Function Tests Before and After Pulmonary Rehabilitation

Table 3: Six-Minute Walk Distance (6MWD) Before and After Pulmonary Rehabilitation

Table 4: St. George’s Respiratory Questionnaire (SGRQ) Scores Before and After Pulmonary Rehabilitation

The findings of this prospective study demonstrate that an 8-week structured pulmonary rehabilitation (PR) program significantly improves pulmonary function, exercise capacity, and quality of life in post-COVID-19 patients with persistent respiratory dysfunction. Our results align with prior evidence suggesting that targeted rehabilitation interventions can substantially aid recovery from post-viral syndromes and respiratory impairments (1,2).

Pulmonary function improvements, particularly in FVC and FEV1, were statistically significant in our cohort. Similar enhancements have been observed in earlier studies evaluating the impact of PR in COVID-19 survivors (3,4). Huang et al. reported persistent reduction in lung function parameters at 6 months following acute infection, highlighting the need for long-term management strategies (5). PR addresses not only alveolar-capillary damage but also mitigates respiratory muscle weakness, deconditioning, and systemic inflammation, all of which contribute to post-COVID morbidity (6).

Exercise capacity, measured by the six-minute walk distance (6MWD), significantly increased post-rehabilitation, consistent with observations by Liu et al., who found that a 6-week PR intervention improved functional status in COVID-19 patients (7). Physical inactivity due to prolonged hospitalization and isolation often leads to sarcopenia and impaired cardiopulmonary fitness, which structured exercise programs can reverse (8). Moreover, improvements in 6MWD are directly associated with better survival rates and reduced hospital readmissions in patients with respiratory disease (9).

Quality of life, as assessed by the SGRQ, also showed substantial enhancement. Psychological distress, fatigue, and dyspnea are key components of post-COVID syndrome that significantly impact daily living (10). Pulmonary rehabilitation, by integrating educational and psychosocial support components, helps in restoring psychological resilience and functional independence (11). Previous studies in chronic obstructive pulmonary disease (COPD) and interstitial lung disease populations have demonstrated that PR programs lead to a clinically meaningful reduction in SGRQ scores (12,13), a finding mirrored in our study population.

Interestingly, no major adverse events were recorded during rehabilitation, emphasizing the safety and feasibility of implementing PR in post-COVID care even among patients with moderate respiratory compromise. This observation corroborates findings from a multicenter cohort where PR was safely administered without significant complications in post-COVID patients (14).

However, certain limitations must be acknowledged. The study was observational and lacked a control group, which limits causal inference. Additionally, the sample size was relatively small and from a single center, potentially affecting generalizability. Future randomized controlled trials with larger cohorts are needed to validate our findings and optimize PR protocols specifically tailored for COVID-19 survivors (15).

In conclusion, this study provides robust evidence that pulmonary rehabilitation should be considered an integral component of multidisciplinary management for post-COVID-19 patients with persistent respiratory dysfunction. Early initiation of PR programs may accelerate recovery, improve physical performance, and enhance overall quality of life.

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