Rationale and Design of RECOVER-ENERGIZE: A Platform Clinical Trial of Interventions for Exercise Intolerance With and Without Post-exertional Malaise in Long COVID

Introduction: A prominent symptom of post-acute sequelae of SARS-CoV-2 infection (i.e., Long COVID) is exercise intolerance with or without post-exertional malaise (PEM). PEM is characterized by the worsening of both symptoms and function following even minor physical or mental exertion, with symptoms typically worsening 12 to 48 hours after activity and lasting for days or even weeks. Individualized, supervised cardiopulmonary rehabilitation is considered a safe and effective intervention for many cardiac and pulmonary conditions, and has been effective in gradually improving function in previously hospitalized and nonhospitalized patients with severe COVID-19. While traditional cardiopulmonary rehabilitation approaches appear helpful in some situations, the exercise intolerance symptoms experienced by many individuals with Long COVID may require a different approach, especially when attempts to increase physical activity result in PEM. No clear consensus exists on the optimal treatment of PEM, and no major studies have evaluated the efficacy in individuals with Long COVID of either carefully supervised, individualized cardiopulmonary rehabilitation programs for exercise intolerance without significant PEM or activity pacing interventions designed to treat or prevent PEM. Methods and Analysis: The Researching COVID to Enhance Recovery Clinical Trials (RECOVER-CT) initiative funded by the National Institutes of Health (NIH) included a prospective, multicenter, randomized controlled platform trial (RECOVER-ENERGIZE) designed to assess two interventions in patients with Long COVID and exercise intolerance: (1) cardiopulmonary rehabilitation for patients without significant PEM and (2) structured activity pacing to prevent or reduce PEM in participants who experience the symptom. The intervention duration will be 12 weeks. The primary endpoints for the trial include the Endurance Shuttle Walk Test as a measure of endurance capacity for the cardiopulmonary rehabilitation intervention and a modified version of the DePaul Symptom Questionnaire - Post-Exertional Malaise for the pacing intervention. Assessments will be completed at baseline, middle of intervention, end of intervention, and 12 weeks after completion of the intervention, and include physical performance measures and patient-reported surveys. Ethics and Dissemination: The RECOVER-ENERGIZE trial protocol has been approved by an institutional review board (Advarra), and written informed consent will be obtained from all participants prior to enrollment. The trial is registered on ClinicalTrials.gov (NCT06404047). Formally assessing PEM and developing a structured activity pacing intervention delivered by local pacing coaches are novel features of this trial. Results will be disseminated through peer-reviewed publications, presentations at scientific conferences, and communication with participants, patient advocacy organizations, and the broader Long COVID community. De-identified participant data will be made available through the NIH RECOVER data repository in accordance with NIH data-sharing policies. If successful, this protocol will provide accessible tools that clinicians can use to address exercise intolerance and PEM in patients with Long COVID.