Is physical exercise a multiple sclerosis disease modifying treatment?

INTRODUCTION: There is consensus that exercise represents a behavioral approach for the restoration of function and management of symptoms among persons with multiple sclerosis (MS). The current paper provides a review on the topic of exercise and physical activity as MS-disease modifying treatments. AREAS COVERED: Firstly, metrics for evaluating disease modification and progression in MS are described. Secondly, evidence for exercise as a MS-disease modifying therapy based on individual studies, literature reviews, and meta-analyses is summarized. Finally, the paper focuses on major limitations of the existing body of research. Expert commentary: Exercise and physical activity have been associated with reduced relapse rate, mobility disability and its progression, and lesion volume, and improved neuroperformance, particularly walking outcomes. This evidence provides a positive, yet preliminary, picture for exercise having possible effects on markers of disease modification and progression in MS.