The purpose of this study is to investigate underlying mechanisms possibly explaining the beneficial effects of progressive resistance training for people with multiple sclerosis.

Exercise in general, and progressive resistance training (PRT) in particular, is regarded as an important tool in the rehabilitation of people with multiple sclerosis (MS).

Previous studies have reported positive effects of PRT on muscle strength, functional capacity, fatigue and quality of life. Also, a possible disease modifying effect has been proposed. However, the underlying physiological mechanisms that might explain these beneficial effects and the possible effects on disease progression are unresolved. Additionally, none of the previous studies has been concerned with the possible impact of MS progression type, gender and/or medication.

The purpose of this randomized, controlled, gender stratified trial is to investigate underlying mechanisms possibly explaining the beneficial effects of progressive resistance training for people with multiple sclerosis.

Inclusion Criteria:

• Diagnosed relapsing-remitting MS according to the McDonald criteria
• Expanded Disability Status Scale (EDSS) between 2.0 and 5.5
• Be able to train twice a week at the University
• Use interferon based medication

Exclusion Criteria:

• Alcohol abuse, Alzheimer's and pacemaker (or other metallic implant)
• Comorbidities like cardiovascular-, respiratory-, orthopaedic or metabolic diseases
• Having had an attack in a period of 8 weeks prior to the start of the intervention period
• Having an attack during the intervention period
• Pregnancy
• Systematic resistance training in a period of 3 months prior to the start of the intervention period.
• Training adherence of less than 85%.