The purpose of the study is to explore the biomarker Fast Troponins response to exercise in patients with Becker muscular dystrophy, Limb-girdle muscular dystrophy and McArdle disease

Inclusion Criteria:

• The ability to cycle
• No concurrent medical condition that could interfere with interpretation of the results
• Molecular diagnosis of the specific condition in specified patient groups or healthy control
• No active muscle injury on the test day (caused by recent exercise, seizures, trauma, etc.)

Exclusion Criteria:

• Competing conditions at risk of compromising the results of the study
• Cardiac or pulmonary disease contraindicating peak exercise testing or strenuous exercise
• Veins that are too difficult to puncture for blood sampling, evaluated by the investigator
• Severe muscle weakness, that prevents the subject completing the exercise test, evaluated by the investigator

Patients with McArdle disease and patients with two sub-typesof Limb-girdle and Becker muscular dystrophies will be included as well as healthy controls.