Evaluation of Exercise Rehabilitation Programs to Improve Cardiac and Respiratory Health in COVID-19 Patients: A Systematic Review of Randomized Controlled Trials

Introduction: Coronavirus disease 2019 (COVID-19) survivors have suffered from long-term impacts of the disease. Many survivors are experiencing persistent cardiac and respiratory complications. Some studies have shown that exercise-based rehabilitation plays a critical role in the recovery of post-COVID-19 patients in order to minimize complications such as dyspnea, breathlessness, and heart failure. Objective: The objective of this study was to evaluate the effectiveness of exercise-based rehabilitation programs to improve cardiac and respiratory functions in COVID-19 patients. Methodology: An extensive search of literature was conducted on PubMed, Cochrane Central Register of Controlled Trials, and TRIP databases using the following keywords and Boolean operators: High intensity interval training (HIIT) OR rehabilitation OR COVID-19 OR exercise AND long COVID. Randomized controlled trials (RCTs) published in the English language from 2020 to 2024 were included in the study. Full-text articles were reviewed and Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines were implemented during this systematic review. Patients who had pre-existing cardiac and respiratory complications were excluded from the study. Results: This systematic review included 5 RCTs involving 291 participants. The rehabilitation (intervention) groups showed notable improvements in VO2 peak with pooled data (ES = 0.765, SE = 0.193, 95% confidence interval CI 0.391, 1.139). The mean difference (MD) for VO2 peak was 2.42, maximum, heart rate (HR max) increased (MD = 5.33), and the left ventricular mass increased by MD = 6.8 (95% CI: 0.8; 12.8 g; P = 0.029) indicating enhanced cardiovascular conditioning and function. Maximum voluntary ventilation (MD = 5.3) improved respiratory endurance along with an increased stability in FEV1 and FVC. In addition, a drastic improvement in the ventilatory efficiency and breathing patterns was noted, thus reducing perceived dyspnea. HIIT intervention: Two participants showed a reduction in their predicted residual volume % (8%) and total lung capacity. In comparison, the control group showed no significant improvement. Conclusion: Exercise-based rehabilitation programs have shown improvement in cardiac and respiratory functions by decreasing symptoms such as dyspnea, palpitations, and failure. By integrating such rehabilitation programs into post-COVID care, long-term recovery can be significantly improved.