Summary
The worldwide pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has impacted all healthcare systems. One potential sequela experienced by hospitalized coronavirus disease 2019 (COVID-19) survivors includes muscle weakness with a reduction in strength and, consequently, a possible increase in frailty. The aim of this clinical trial was to evaluate the efficacy of adding an online therapeutic exercise program for 8 weeks to the medical prescriptions on functional variables in patients hospitalized due to COVID-19. A randomized controlled trial including 70 previously hospitalized COVID-19 survivors was conducted. Patients were randomly allocated to an experimental (n = 35) or control (n = 35) group. Both groups received regular prescriptions provided by their medical doctors. The experimental group also received a live online therapeutic exercise program for 8 weeks (3 sessions/week). Handgrip strength, gait speed, lower-extremity strength, balance, and frailty were assessed at baseline, at the end of the program, and one month after the end of the intervention. The repeated measures analysis of variance revealed significant Group*Time interactions for all the outcomes: (handgrip dominant: F = 17.395, p < 0.001, η2 = 0.24; handgrip non-dominant: F = 33.197, p < 0.001, η2 = 0.33; 4 m walk test (4WT): F = 13.039, p = 0.001, η2 = 0.16; short physical performance battery (SPPB): F = 26.421, p < 0.001, η2 = 0.28; the five chair-raise test (5CRT): F = 5.628, p = 0.004, η2 = 0.08; FRAIL scale: F = 11.249, p = 0.001, η2 = 0.14): patients in the experimental group experienced greater improvements in all outcomes than those assigned to the control group. This study revealed that the addition of an online exercise program for 8 weeks obtained greater improvements in handgrip strength, gait speed, lower-extremity strength, balance, and frailty in a sample of previously hospitalized COVID-19 survivors than application of just usual medical prescription.

Relevance
An online exercise program combined with medical prescriptions for 8 weeks exerted greater improvements in handgrip, 4MW, SPPB, 5CRT, and FRAIL scale in individuals who had been hospitalized by COVID-19 compared to usual medical prescription. Tele-rehabilitation programs could help to manage people at risk after COVID-19 hospitalization.