The objective of this study is to evaluate the effect of strength training for the lower extremities and treadmill training on walking ability in persons with Multiple Sclerosis. The study is a randomized control trial with two groups and the intervention is 8 weeks of intensive strength training or treadmill walking. Primary outcome measure is walking ability, secondary outcome measures are balance, work economy and strength.

Inclusion Criteria:

• Diagnosed with Multiple Sclerosis,classified as relapsing remitting,or primary/secondary progressive
• Expanded Disability Status Scale (EDSS)score of ≤ 6
• Reduced walking ability (subjectively experienced)

Exclusion Criteria:

• persons with a level of ataxia, clinically assessed, that would affect their ability to perform the training.
• spasticity requiring stretching og treatment with baclofen.
• Other, not MS-related, conditions affecting walking ability.