Why Leg Exercise Improves Brain Health

“Toe bone connected to the…foot bone
Foot bone connected to the…heel bone
Heel bone connected to the…ankle bone
Ankle bone connected to the shin bone…”

There’s an old spiritual song called “Dem Bones” or “Dry Bones.” If you heard it when you were a kid, you inevitably pictured a skeleton with the bones connected in order from the toes to the skull. Even a child knows that the leg bone is not connected to the head bone. Or is it?

Well, it’s obviously not a direct connection, but a recent study tells us that moving our legs is definitely connected to the health of the organ housed inside the skull: the brain. The study addresses a kind of “which came first, the chicken or the egg?” question. In degenerative disease that gradually impair a person’s ability to get around, is the neurological disorder that diminishes movement, or does restricted movement harm the brain?

The study, “Reduction of Movement in Neurological Diseases: Effects on Neural Stem Cells Characteristics,” is the work of an Italian research team.i They experimented with severely limiting the hind leg movements of mice (but not their front legs) for 28 days. To all outward appearances, the mice continued normal eating and grooming behaviors and did not appear stressed. At the end of 28 days, the team examined a specific area of the animals’ brains to look for changes at the cellular level.

Changes in brain cells

The particular part of the brain on which the study focused plays an important role in nurturing brain cells, called neurons. Not only does this area help maintain neuron health, it’s also where neuron stem cells develop into new neurons.

What the team discovered has been described as “groundbreaking.”ii They found that compared to control mice whose leg movements were not limited, the experimental mice had a 70% reduction in neural stem cells. This obviously handicaps the brain’s ability to generate new neurons. Also, the types of cells that support and insulate neurons were not able to fully develop and mature when the mice were deprived of exercising their hind legs, which contain major muscle groups just as our own two legs support our weight and do the heavy work of walking, running, climbing stairs, etc.

This demonstrates that there is a two-way street that connects the brain and the legs. As one team member described it, it’s not just the brain giving instructions to the legs to move, it’s also the moving legs promoting a fully functional and self-preserving brain.

More exercise effects

Other research supports the negative effect of a sedentary lifestyle on the brain—and other parts of the body. Lack of regular vigorous weight-bearing exercise (e.g. aerobic walking or jogging) to use the large leg muscles short-changes both heart and head wellness.

A May 21, 2018 news release about research out of Massachusetts General Hospital reports, “Vascular risk factors increase the risk of cognitive impairment in older individuals and appear to have a negative synergistic effect with levels of brain amyloid-beta, the protein that aggregates into neurotoxic plaques in the brains of individuals with Alzheimer’s disease.” In other words, if you’re not taking care of your heart muscle and circulatory system, you’re indirectly encouraging toxic brain build-up that accelerates age-related declines in thinking and mental health.

The work of the Italian researchers underscores this and more. Their findings with the mice “…shed light on several important health issues, ranging from concerns about cardio-vascular impacts as a result of sedentary lifestyles to insight into devastating diseases, such as spinal muscular atrophy (SMA), multiple sclerosis, and motor neuron disease, among others.”iii

Essential tremor and worries about exercise

Many people with essential tremor (ET) become concerned about vigorous exercise. They may find that pushing their heart rate up aggravates their tremors to a point where they are more pronounced and difficult. However, this is not a permanent effect, and once the body returns to its resting state, tremors return to their current base profile. Some research has shown that exercising the upper arms with weights or gym machines may initially worsen tremors, but it improves fine motor coordination of the hands over time. Getting individual consultation, perhaps from a physical therapist familiar with movement disorders, can help tailor a program that boosts brain health without making tremors more difficult to live with.

The bottom line is, making your legs work is in your brain’s best interest.

iAdami R, Pagano J, Colombo M, Platonova N et al. Reduction of Movement in Neurological Diseases: Effects on Neural Stem Cells Characteristics. Frontiers in Neuroscience, 2018; 12 DOI: 10.3389/fnins.2018.00336

iii“Leg exercise is critical to brain and nervous system health.” Science Daily, May 23, 2018. https://www.sciencedaily.com/releases/2018/05/180523080214.htm


About Dr. Dan Sperling

Dan Sperling, MD, DABR, is a board certified radiologist who is globally recognized as a leader in multiparametric MRI for the detection and diagnosis of a range of disease conditions. As Medical Director of the Sperling Prostate Center, Sperling Medical Group and Sperling Neurosurgery Associates, he and his team are on the leading edge of significant change in medical practice. He is the co-author of the new patient book Redefining Prostate Cancer, and is a contributing author on over 25 published studies. For more information, contact the Sperling Neurosurgery Associates.

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