Inclusion Criteria:  Age ≥ 40 year Written informed consent Diagnosed with idiopathic Parkinson's disease Hoehn & Yahr ≤ 3 Taking dopaminergic medication Able to complete a maximal aerobic test on a bicycle  Exclusion Criteria:  Dementia Alcohol abuse Pacemaker Serious cardiovascular, respiratory, orthopedic or other comorbidities excluding maximal exercise participation. Pregnancy