I1. Subjective muscular fatigue after confirmed COVID-19, and either/or: o Proximal weakness on examination (MRC score) o I1.1 6 min walk test <80% of expected or signs of proximal weakness at physical examination o I1.2 Abnormal decrement on repetitive nerve stimulation in medical history I2. Disease duration of ≥ 3 months I3. Residual symptoms with a FAS I4. Age <65 years I5. Ability to understand the requirements of the trial and provide written, informed consent

I1. Subjective muscular fatigue after confirmed COVID-19, and either/or: o Proximal weakness on examination (MRC score) o I1.1 6 min walk test <80% of expected or signs of proximal weakness at physical examination o I1.2 Abnormal decrement on repetitive nerve stimulation in medical history I2. Disease duration of ≥ 3 months I3. Residual symptoms with a FAS I4. Age <65 years I5. Ability to understand the requirements of the trial and provide written, informed consent