The aim of this study was to determine the effectiveness of physical exercise, respiratory muscle training and the self-management WHO recommendations leaflet on the recovery of physical fitness, quality of life and symptom status in people with post COVID-19 conditions. Eighty non-hospitalized adults with a post-COVID-19 condition were randomly assigned to one of four 8-week parallel intervention groups: multicomponent exercise program based on concurrent training- CT (n= 20; 3 resistance and endurance supervised sessions per week at low-moderate intensity); b) inspiratory muscle training- RM (n= 17; 2 standardized daily sessions); c) a combination of both of the above- CTRM (n= 23); d) control group- CON (n= 20; following the WHO guidelines for post-COVID-19 related illness rehabilitation). No significant differences between groups were detected at baseline. While no significant differences between interventions were detected in the VO2max, significant individual improvements were identified in the CT (7.5%; ES=0.38) and CTRM (7.8%; ES=0.28) groups. Lower body muscle strength significantly improved in the CT and CTRM (14.5-32.6%; ES=0.27-1.13) groups compared to RM and CON (-0.3-11.3%; ES=0.19-0.00). The CT and CTRM groups improved significantly for dyspnea and fatigue, as did the health status. In addition, significant differences between interventions were described in fatigue and depression scales favouring CT and CTRM interventions. An individualized and supervised concurrent training with or without respiratory muscle training was safer and more effective than self-care recommendations and inspiratory muscle training alone, to regain cardiovascular and muscular fitness, improve symptom severity and health status in outpatients with post-COVID-19 conditions.