Exploring the Link Between ALS Progression and Physical Activity

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that leads to the loss of motor control through motor neuron degeneration, such as the degeneration of upper and lower motor neurons causing muscle weakness and the inability to control limbs and normal functions like breathing. Around 9.1 per 100,000 people in the United States and 1-7 per 100,000 people globally are diagnosed with ALS, with a general age range of 40-70 years old. On average, a patient with ALS will live for three years, with only 5% living for more than 20 years. This disease is currently largely unknown to medicine, with only a few identified risk factors, difficult differential diagnosis, and no disease-modifying therapies available. However, physical activity and exercise seem to have an impact on ALS patients through particular muscles and neurons, whether as a way to develop ALS or treat it. A main limitation in this field of research is the lack of clear definitions and measurements of physical activity and exercise. This paper explores the roles of physical activity as a risk factor and protective factor of ALS and calls for the need to precisely and thoroughly describe and measure it. Mainly, anaerobic activity and leisure time activity act as a risk factor for ALS, while swimming shows a neuroprotective effect on murine models of ALS and combined endurance and resistance shows functional improvement in early stages of ALS in patients.