Inclusion Criteria  Confirmed diagnosis of MS from a neurologist using the McDonald diagnostic criteria Ability to ambulate independently with or without an assistive device Current, previous, and nonsmokers Age ≥ 18 years Ability to give informed consent.  Exclusion Criteria  A neurological disease other than MS Orthopedic problems or other conditions that may significantly interfere with testing Uncorrected vision loss Acute ischemic cardiovascular event or coronary artery bypass surgery less than 3 months ago Uncontrolled blood pressure with medication (BP>190/110mmHg).