Moderate levels of physical activity and fitness may be linked to a reduced risk of amyotrophic lateral sclerosis (ALS) later in life, according to a new study published in the June 26, 2024, online issue of Neurology, the medical journal of the American Academy of Neurology.
The study only found an association between physical activity and risk of ALS in male participants, not female participants.
For the study, researchers looked at 373,696 people in Norway with an average age of 41. They were followed for an average of 27 years.
Of the total participants, 504 people developed ALS. Of those who developed ALS, 59% were male participants.
Participants recorded their level of physical activity for the past year into one of four categories: sedentary; a minimum of four hours per week of walking or cycling; a minimum of four hours per week of recreational sports or heavy gardening; or participation in hard training or sports competitions regularly, several times a week. Due to few participants with the highest level of physical activity, researchers combined the third and fourth categories into one high activity group.
Researchers found that of the 41,898 male participants that had the highest level of physical activity, 63 developed ALS; of the 76,769 male participants with the intermediate level of physical activity, 131 developed ALS; and of the 29,468 male participants with the lowest level of physical activity, 68 developed ALS.
After adjusting for other factors that could affect the risk of ALS, such as smoking and body mass index, researchers found that for male participants, when compared to those with the lowest level of physical activity, those with moderate levels of physical activity had a 29% lower risk of ALS and those with high levels of physical activity had a 41% lower risk of ALS.
Researchers also looked at resting heart rate. Men in the lowest of four categories of resting heart rate, which indicates good physical fitness, had a 32% reduced risk of ALS compared to those with higher resting heart rates.
