Background and purpose: Amyotrophic lateral sclerosis (ALS) is an idiopathic disease of adults affecting upper and lower motor neurons. In one to four years, progressive weakness, spasticity, and respiratory insufficiency compromise independence and survival. Current medical treatment is limited to medication and supportive care. The benefit and harm of moderate physical exercise are controversial. This review examined current research related to moderate exercise for maintaining independence without accelerating disease progression in persons with ALS.

Methods: An evidence-based search was conducted using keywords alone and in combination (ALS, exercise, Lou Gehrig's disease, physical therapy) to search PubMed, PEDro, Hooked on Evidence, Ovid, and Cochrane databases. Human and animal models were included and graded on level of evidence and strength of recommendations for developing guidelines to practice. A secondary reviewer evaluated all selected studies, and statistics were calculated.

Results: The search yielded the following nine studies: four small clinical studies, one clinical systematic review, and four randomized, controlled trials based on animal models. In human studies, there were small to moderate effect sizes supporting the benefit of moderate exercise in persons with early-stage ALS, with no adverse affects on disease progression or survival time. In transgenic mice with superoxide dismutase-1 ALS, moderate exercise most often had a moderate effect size for increasing life span.

Discussion and conclusion: Large randomized clinical trials are needed to develop specific exercise guidelines. However, evidence suggests that moderate exercise is not associated with adverse outcomes in persons with early-stage ALS. Moderate exercise programs can be safely adapted to abilities, interests, specific response to exercise, accessibility, and family support.