Aerobic Exercise and Flu-like Symptoms Following Interferon Beta 1a Injections in Patients With Multiple Sclerosis?

Inclusion Criteria: * Definite relapsing-remitting MS according to the McDonald criteria * Treated with IFNß-1a (Avonex®) for at least 6 months * Frequent experiencing FLS (muscle aches, chills, fatigue, fewer9) in the hours following IFNß-1a injection (self-reporting that this happens 75% or more of the times after injection). * Female subjects of childbearing potential are required to practice effective contraception during the study and to continue contraception for 30 days after their last dose of study treatment. * Expected to be able to complete the aerobic exercise intervention * Willingly to transport themselves to the exercise/testing facility * Give informed consent * Age above 18 years Exclusion Criteria: * Have FLS (i.e. muscle aches, chills, fatigue or fewer) or serious infection within a 24h period prior to the screening. Patients having chronic FLS or infection will, therefore, be excluded. This will be tested by patient interview and, if required, further examination * Have a known history or positive test result for hepatitis B, hepatitis C, or HIV * Use beta-blockers. * Have clinically significant abnormality in laboratory or electrocardiogram measures, chronic fatigue syndrome or fibromyalgia, pre-malignant disease, or malignant disease * Have had allergy shot or desensitization therapy within 1 month of day 1 (randomization) vaccination within 2 weeks of day 1. * Stop taking IFNß-1a. * Are pregnant. * Suffer from dementia, alcohol abuse or have a pacema…