Inclusion Criteria:  laboratory-confirmed infection with SARS-CoV-2 via PCR a minimum of 12 weeks ago presence of at least one or more of persistent symptoms that can be attributed to Post-COVID/Long-COVID or a manifestation of reduced physical performance capacity since the infection with SARS-CoV-2  Exclusion Criteria:  previous or current hospitalization due to the COVID-19 disease regular engagement in endurance or strength training (more than once per week) in the six months prior to enrollment contraindications for physical endurance and resistance exercise according to the guidelines of the American College of Sports Medicine (ACSM) clinical diagnosis of depression clinical diagnosis of anxiety clinical diagnosis of a sleep disorder clinical diagnosis of a cognitive deficit disorder a grade of 3 or higher on the Post-COVID-19 Functional Status Scale (PCFS) presence of post exertional malaise (PEM)