Due to restricted and new rules for data protection, the use of an app could not be approved

The study is a controlled, randomized intervention trial. Patients are randomized into either an intervention group or a control group. The duration of the study is 10 weeks. Patients in the intervention group participate in a 10 weeks exercise program consisting of 150 minutes interval walking per week administered by an app on the patient's telephone. Patients in the control group live as usually, with a maximum of 30 minutes aerobic exercise per week.

Before and after the 10 weeks study period, patients (from both the intervention and the control group) participate in a 2 hours session of functional testing (e.g. walk tests, test of muscle strength ect.) at Rigshospitalet.

Inclusion Criteria:

• Able to provide signed informed consent.
• Able to read and understand Danish or English.
• Diagnosed with mild to moderate myasthenia gravis (I-IV on the Myasthenia Gravis Foundation of American Clinical Classification, MGFA).
• Documented history of acetylcholine receptor (AChR) or Muscle Specific Kinase (MuSK) antibody positive, or abnormal repetitive nerve stimulation testing (decrement > 10%) on EMG or abnormal single fiber EMG (conduction block or jitter) or based on their clinical history and symptom improvement with acethylcholinesterase inhibitors.
• If the patient is on oral corticosteroids, the dose must be stable for at least 1 month prior to inclusion.
• If the patient is on cholinesterase inhibitors the dose must be stable 2 weeks prior to inclusion.

Exclusion Criteria:

• MGFA grade V disease
• Other disorders that are not related to MG, or drugs, that interfere with muscle strength, balance and fatigue.
• Serious medical illness (e.g. uncontrolled insulin dependent diabetes mellitus, symptomatic coronary artery disease, and cancer).
• Dementia or pregnancy.
• Unspecified reasons judged by the investigator.