ABSTRACT
BACKGROUND: The best exercise program for individuals with effort intolerance or hypoxia at rest and/or during exercise post-COVID-19 treatment who have already had in-hospital rehabilitation remains unknown. OBJECTIVE: We evaluated the efficacy of a home-based rehabilitation exercise program intervention that included teleconsultations with a specialist nurse. METHODS: This was a multicenter randomized controlled trial for individuals who had been diagnosed with, and treated for, COVID-19. Despite inpatient rehabilitation they still had effort intolerance; this was defined as being a) only able to walk <70 % of the predicted distance during the six-minute walking test (6MWT) and/or b) oxygen desaturation all day long/during effort. The primary outcome was effort tolerance, as evaluated by the 6MWT. Secondary outcomes were dyspnea, fatigue, spirometry, respiratory muscle evaluations, and oxygenation. The Intervention group performed 4 weeks of a self-directed exercise program with bi-weekly physiotherapist video calls; the Control group participated in physical activity howsoever they wished. Exercises were divided into 4 intensity levels according to disability and oxygen desaturation. The program progressively increased from low (walking, free-body exercise, sit-to-stand, and balance exercises) to high (speed walking with a pedometer, cycle ergometer, and strengthening exercises). RESULTS: We included 79 participants: 40 in the Intervention and 39 in the Control group. Mean (SD) age was 67.1 (10.3) years; 72 % (n = 57) were male. No intergroup differences in effort tolerance were found [Intervention 77.6 (75.4)m vs Control 49.5 (73.3)m (p = 0.109)]. Participants with 6MWT distance results < lower limit of normality values showed best improvements in mean (SD) effort tolerance: Intervention, 120.1 (75.8)m vs Control, 59.1 (75.6)m (p = 0.035). After 2 months, mean (SD) 6MWT distances in the 2 groups were similar: Intervention, 475.9 (82.4)m vs Control, 469.2 (118.9)m (p = 0.807). CONCLUSIONS: In individuals with residual disability post-COVID-19 and after inpatient rehabilitation, a home-based exercise program with teleconsultation significantly improves effort tolerance but only for people who had severe effort intolerance at baseline. DATABASE REGISTRATION: ClinicalTrials.gov number, NCT04821934.
