 MS is a complex disease with heterogenous symptoms, and by combining the disciplines of exercise physiology, neurology and radiology this study can be the first long-term and large-scale exercise study to investigate the possible neuroprotective and disease-modifying effects of exercise when initiated early in the disease course of MS. Consequently, this project has the potential to change present clinical practice and generate further attention to exercise, not only as symptom treatment, but also as an supplemental disease-modifying treatment strategy early in the course of MS. 