The Grapevine

Leg Exercise Benefits Brain Health, Sends Vital Signals For Cell Production: Study

Here's another reason to take the stairs more often. A new study suggested regularly moving your legs, especially when bearing weight, is essential for the production of healthy neural cells.

The paper titled “Reduction of Movement in Neurological Diseases: Effects on Neural Stem Cells Characteristics” was published in Frontiers in Neuroscience on May 23.

“It is no accident that we are meant to be active: to walk, run, crouch to sit, and use our leg muscles to lift things,” said Dr. Raffaella Adami from the Università degli Studi di Milano, Italy. “Neurological health is not a one-way street with the brain telling the muscles 'lift,' 'walk,' and so on.”

Researchers performed a 28-day experiment where they allowed a group of mice to use their front legs but restricted them from being able to use their hind legs. The mice ate, groomed, and displayed normal behavior without any signs of exhibited stress. After 28 days, the researchers studied the brains of the animals, particularly the sub-ventricular zone where neurons are produced by neural stem cells.

When compared to a control group of mice who were unrestricted and allowed to roam, the number of neural stem cells decreased by 70 percent in the mice that had restricted physical activity. Researchers also noted both neurons and oligodendrocytes (specialized neural cells) were unable to fully mature when physical activity was reduced. 

"Our study supports the notion that people who are unable to do load-bearing exercises — such as patients who are bed-ridden, or even astronauts on extended travel — not only lose muscle mass, but their body chemistry is altered at the cellular level and even their nervous system is adversely impacted," said Adami.

By studying individual cells, the researchers noted alterations in the metabolism of the mice due to reduced oxygen from the lack of exercise. Additionally, the reduced capacity for movement impacted the health of mitochondria, which is responsible for releasing energy to the body.

Neurological diseases such as spinal muscular atrophy (SMA) have been an area of interest for co-author Dr. Daniele Bottai since 2004.

She said: “The question I asked myself was: is the outcome of these diseases due exclusively to the lesions that form on the spinal cord in the case of spinal cord injury and genetic mutation in the case of SMA, or is the lower capacity for movement the critical factor that exacerbates the disease?”

In other words, the researchers believe our brain and leg muscles have a two-way relationship where neurological health is dependent on signals sent by the leg muscles as much as the muscle health depends on directives from the brain.

The findings could potentially help medical professionals gain a better understanding of why patients with motor neuron disease, SMA, multiple sclerosis and other neurological diseases see their condition worsen when their movement becomes limited. 

“One could say our health is grounded on Earth in ways we are just beginning to understand,” Bottai added.