Moderate Physical Activity Linked to Reduced Risk of ALS in Men: Study

Being moderately to highly physically active cuts men’s risk of developing amyotrophic lateral sclerosis (ALS) later in life by about 30 percent to 40 percent.

TORWAISTUDIO/Shutterstock

Moderate to high levels of physical activity can reduce the risk of developing amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, in men but not women, a new study shows.

The study, published in Neurology on June 26, found that men who reported moderate levels of physical fitness were 29 percent less likely to develop ALS than sedentary men, while very active men had a 41 percent reduced risk of developing the disease.

“The diagnosis of prominent athletes with ALS at young ages has sparked the uncomfortable idea that higher physical activity could be tied to developing ALS,” Dr. Anders Myhre Vaage of Akershus University Hospital in Norway, a study co-author, said in a statement.

ALS is a fatal motor neurodegenerative disease. Its other name is after Major League Baseball Hall of Famer Lou Gehrig, who died from ALS. The disease causes progressive degeneration of the nerve cells within the spinal cord and brain. Most people with ALS die from respiratory failure after they lose nerve function in the nerves that help them breathe.

“There have been conflicting findings on levels of physical activity, fitness and ALS risk. Our study found that for men, living a more active lifestyle could be linked to a reduced risk of ALS more than 30 years later,” Dr. Myhre Vaage said.

The study authors wrote that in women, no association was detected between self-reported levels of physical activity or resting heart rate and ALS risk.

Higher Levels of Physical Activity Linked to Lower Risk

Norwegian researchers evaluated survey responses recorded between 1985 and 1999. More than 373,500 people were asked about their physical activity, resting heart rate, and cardiovascular risk factors. The average age of participants was about 41.

The research team followed up with the participants up to three decades years later and found that about 500 had developed ALS.

Men with the lowest resting heart rate—an indication of physical fitness—had a 32 percent reduced risk of developing ALS compared to those in the second-highest quartile.

“Our findings show that, for men, not only do moderate to high levels of physical activity and fitness not increase the risk of ALS, but that it may be protective against the disease,” Dr. Myhre Vaage said.

People with moderate or high physical activity exercised or were active for at least four hours per week.

The authors noted that in Parkinson’s disease, another neurodegenerative motor disease, studies have also shown that physical activity had a protective association in men but not in women.

“Future studies of the connection between ALS and exercise are needed to consider sex differences and higher or professional athlete physical activity levels,” Dr. Myhre Vaage said in the statement.

ALS typically affects people between ages 40 and 70, although it can occur at a younger age. It affects individuals of all races and ethnic groups. About 90 percent of the cases of ALS in the United States are sporadic, meaning they occur randomly without any known genetic cause, but about 10 percent are thought to be a result of genetics.

People with ALS usually begin to feel progressive muscle weakness as they start to lose muscle control. Eventually, a person will lose the ability to control most, if not all, muscle movement, leading to total paralysis and death.