The purpose of this study is to compare the safety and the effects of moderate-intensity aerobic endurance training to those of an usual physical therapy intervention on exercise capacity and quality of life in patients with amyotrophic lateral sclerosis (ALS).

Scarce evidence is available regarding aerobic exercise training of patients with ALS. Some studies using transgenic mouse models of familial ALS have shown markedly slowed disease progression, improved functional capacity, and extension of survival in animals undergoing aerobic exercise training. In humans, only one non-randomized study has shown that moderate-intensity aerobic exercise training was of little beneficial effect in a small group of patients with Kennedy disease, a rare X-linked progressive neuromuscular disease involving lower motorneurons, presenting a pathophysiological picture quite different from that of ALS. To the best of our knowledge, the safety and the effects of aerobic exercise training on functional capacity and quality of life of patients with ALS have not been systematically evaluated as yet in a randomized, controlled trial with an adequate sample size.

Inclusion Criteria:

• Diagnosis of definite ALS, probable ALS, or probable-laboratory supported ALS according to the El Escorial criteria or diagnosis of progressive muscular atrophy.
• Ability to perform a baseline symptom-limited cardiopulmonary exercise test with attainment of peak power and respiratory exchange ratio of >= 50 W and >= 1.00, respectively.
• Time since symptoms onset <= 18 months.
• Forced vital capacity >= 70% of predicted.
• Informed written consent.

Exclusion Criteria:

• Coexisting neurological disease.
• Coexisting extra-neurological disease significantly affecting exercise capacity.
• Coexisting malignancy.
• Ongoing/planned pregnancy.
• Involvement in formal endurance and/or strength training program.
• Enrolment in any other clinical trial.
• Cognitive impairment.