Why could High-intensity Interval Training be Inappropriate in Pulmonary Rehabilitation of COVID-19 Recovered Patients? Opinion Article

Abstract

Pulmonary rehabilitation is a multidisciplinary intervention recommended by international guidelines in the management of COVID-19 patients and/or post-COVID-19 conditions with mid- and long-term complications of the initial illness. Physiotherapy-based pulmonary rehabilitation has been receiving considerable attention since the COVID-19 pandemic, with supervised exercise training being probably the most important component. Current guidelines clearly encourage low- to moderate-intensity exercises to begin with for COVID-19 recovered patients, and discourage high-intensity/vigorous exercises. However, the ongoing interests in high-intensity interval training (HIIT) have extended to post-COVID-19 rehabilitation, based on its efficacy and safety in other patient populations. In this perspective, several reasons behind the possibility of the inappropriateness of the HIIT in post-COVID-19 conditions will be discussed, supported by evidence. In addition, the key points for safe exercise after COVID-19 illness will be listed.