Comparison of High-Intensity Interval Training to Moderate-Intensity Continuous Training for Functioning and Quality of Life in Survivors of COVID-19 (COVIDEX): Protocol for a Randomized Controlled Trial.

OBJECTIVE: The purpose of this study was to compare high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) for feasibility, safety, adherence, and short- and long-term efficacy in improving functioning and health-related quality of life in survivors of coronavirus disease 2019 (COVID-19). METHODS: COVIDEX is a two-pronged, parallel-group, randomized controlled trial with an 8-week training intervention. The study participants will be 94 patients aged >18 years, admitted to a specialized post-COVID center. Participants will be randomized to HIIT (4 × 4 minutes of high-intensity work periods at 85% to 90% of peak heart rate) and MICT (47 minutes at 70% to 75% peak heart rate) groups for biweekly sessions for 8 weeks. The participants will undergo 2 phases of supervised training (phases 1 and 2) of 4 weeks each, in a public, specialized, post-COVID center. In phase 1, we will assess and compare the feasibility, acceptability, and short-term efficacy of HIIT and MICT intervention. In phase 2, the long-term efficacy of HIIT and MICT will be assessed and compared regarding function and health-related quality of life. To prevent any expectation bias, all study participants and assessors will be blinded to the study hypotheses. Group allocation will be masked during the analysis. All statistical analyses will be conducted following intention-to-treat principles. IMPACT: This study is the first randomized controlled trial that will compare the feasibility, safety, adherence, and efficacy of the HIIT and MICT intervention programs in this population. The findings will potentially provide important information and assist in clinical decision making on exercise to optimize the benefits of clinical health care in survivors of COVID-19.

A systematic review on physical function, activities of daily living and health-related quality of life in COVID-19 survivors.

OBJECTIVE: To analyze the published studies that investigated the physical function, activities of daily living and health-related quality of life in COVID-19 survivors. DESIGN: Systematic review. METHODS: We searched MEDLINE/PubMed, Scopus, SciELO, and Cochrane Library for studies that evaluated the physical function, activities of daily living and health-related quality of life after COVID-19 from the earliest date available to July 2021. Two independent reviewers screened and selected the studies. The Newcastle Ottawa Scale was used to evaluate methodological quality. RESULTS: We included 35 studies in this systematic review. Of the 35 studies included, 28 were cohort, and 7 cross-sectional studies The studies demonstrated that COVID-19 survivors had reduced levels of physical function, activities of daily living, and health-related quality of life. Furthermore, incomplete recovery of physical function, and performance in activities of daily living were observed 1 to 6 months post-infection. DISCUSSION: Physical disability and reduction in health-related quality of life is a common condition in post-COVID-19 and impairments may persist up to 1 to 6 months. Researchers and clinicians can use these findings to understand the potential disabilities and rehabilitation needs of people recovering from the COVID-19.