Lung Insufflation Capacity Training and Respiratory Function in Amyotrophic Lateral Sclerosis

The goal of this clinical trial is to determine whether lung insufflation capacity (LIC) training can help maintain respiratory function and prolong tracheostomy-free survival in people with amyotrophic lateral sclerosis (ALS). The main questions are: Does early and continuous LIC training slow the decline in forced vital capacity (FVC)? Does LIC training prolong the time to tracheostomy or death? This single-center study at the National Center of Neurology and Psychiatry (NCNP) in Japan will enroll 25 adults with ALS diagnosed according to the El Escorial or Awaji criteria. This is a single-arm study with no concurrently enrolled control group. Comparative analyses will use matched external controls. PRO-ACT will be used primarily to evaluate short-term respiratory-function trajectories, while JACALS, if data access is approved, will be used primarily to evaluate long-term time-to-event outcomes. Participants will: * Use the LIC Trainer device to perform lung insufflation training twice daily at home * Visit the clinic every 3 months for respiratory and functional assessments * Undergo respiratory tests, including FVC, LIC, maximum insufflation capacity (MIC), and cough peak flow (CPF) * Complete the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R)