Feasibility and Safety of Early Post-COVID-19 High-Intensity Gait Training: A Pilot Study

Background: The feasibility and safety of rehabilitation interventions for individuals recovering from COVID-19 after the acute stage is not well understood. This pilot study aims to provide a preliminary investigation of the feasibility and safety of providing high-intensity gait training (HIT) with a targeted cardiovascular intensity of 70-85% of the age-predicted maximum heart rate (HRmax) for individuals undergoing rehabilitation post-COVID-19. Methods: Consecutive patients who were medically cleared for HIT were invited to participate in the study. Participants practiced walking in varied contexts (treadmill, overground, and stairs), aiming to spend as much time as possible within their target cardiovascular intensity zone during scheduled physical therapy (PT) sessions. Training characteristics and adverse events were collected to determine the feasibility and safety of HIT. The severity of adverse events was graded on a 1-5 scale according to the Common Terminology Criteria for Adverse Events. Results: The participants (n = 20) took a mean of 2093 (+/- 619) steps per PT session. The average peak heart rate during PT sessions was 81.1% (+/- 9.4) of HRmax, and 30.1% (+/- 21.0) of the session time was spent at heart rates >= 70% HRmax. Mild adverse events (grade 1) occurred in <5% of the sessions, and no intervention-requiring or life-threatening adverse events (grade 2-5) occurred. Conclusion: This pilot study provides preliminary evidence that HIT may be feasible and safe during inpatient rehabilitation for patients post-COVID-19 following medical clearance.