Leg exercise is critical to brain and nervous system health
In a new take on the exercise truism ‘use it, or lose it,’ researchers show neurological health is an interactive relationship with our muscles and our world
— By Rachael Bishop, Frontiers science writer
Groundbreaking research shows that neurological health depends as much on signals sent by the body’s large, leg muscles to the brain as it does on directives from the brain to the muscles. Published in Frontiers in Neuroscience, the study fundamentally alters brain and nervous system medicine — giving doctors new clues as to why patients with motor neuron disease, multiple sclerosis, spinal muscular atrophy and other neurological diseases often rapidly decline when their movement becomes limited.
“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,” says Dr. Raffaella Adami from the Università degli Studi di Milano, Italy.
The study involved restricting mice from using their hind legs, but not their front legs, over a period of 28 days. The mice continued to eat and groom normally and did not exhibit stress. At the end of the trial, the researchers examined an area of the brain called the sub-ventricular zone, which in many mammals has the role of maintaining nerve cell health. It is also the area where neural stem cells produce new neurons.
Limiting physical activity decreased the number of neural stem cells by 70 percent compared to a control group of mice, which were allowed to roam. Furthermore, both neurons and oligodendrocytes — specialized cells that support and insulate nerve cells — didn’t fully mature when exercise was severely reduced.
The research shows that using the legs, particularly in weight-bearing exercise, sends signals to the brain that are vital for the production of healthy neural cells, essential for the brain and nervous system. Cutting back on exercise makes it difficult for the body to produce new nerve cells — some of the very building blocks that allow us to handle stress and adapt to challenge in our lives.
“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,” says Adami. “Neurological health is not a one-way street with the brain telling the muscles ‘lift,’ ‘walk,’ and so on.”
Related: Exercise in early life has long-lasting benefits
The researchers gained more insight by analyzing individual cells. They found that restricting exercise lowers the amount of oxygen in the body, which creates an anaerobic environment and alters metabolism. Reducing exercise also seems to impact two genes, one of which, CDK5Rap1, is very important for the health of mitochondria — the cellular powerhouse that releases energy the body can then use. This represents another feedback loop.
These results 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.
“I have been interested in neurological diseases since 2004,” says co-author Dr. Daniele Bottai, also from the Università degli Studi di Milano. “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?”
This research demonstrates the critical role of movement and has a range of potential implications. For example, missions to send astronauts into space for months or even years should keep in mind that gravity and load-bearing exercise play an important role in maintaining human health, say the researchers.
“One could say our health is grounded on Earth in ways we are just beginning to understand,” concludes Bottai.
Original article: Reduction of Movement in Neurological Diseases: Effects on Neural Stem Cells Characteristics
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I think future research will continue to point towards the importance of a body in motion, for instance our legs, stays in motion…keeping the brain in motion too. That we operate and benefit from more of a give and take, vs. the one-way street as previously thought. That everything is connected, and everything serves a purpose. Countless studies point towards the benefits of exercise when combating depression, so it makes sense that it would do more than improve our mood. If we rely on our motor neurons to control these movements, perhaps that final common path is in fact a two-way street.
This seems to link well with FND symptoms too. Fascinating to observe the effects of walking with someone close to me who has had a ‘functional stroke’ – probably more than once.
Nervous system health is yet to be precisely defined. Yet the role of movements / exercise in the extremities particularly the lower limbs with long muscles does require detailed study further. Sedentariness adversely affects cardiovascular health but beneficial component in nervous disease appears promising.
….beneficial component of leg exercise in nervous disease appears promosing. ( mofified )
Interesting article. I guess it is not news that exercise is good for the whole body including the brain and mental health. However it seems to me that it is better news for mice than for humans, as we stop producing neurons in the subventricular zone around age 2. Extrapolating the findings about neurogenesis to humans might not be a good idea.
This is not only important for astronauts….. but also as evidence to schools, where children are forced to sit during long hours in class, and physical activity is being limited more and more.
Thanks to courageous astronauts we now know how very much gravity pulls fluids in our bodies towards the center of the earth so that we stand on our feet at peril to vascularization of suprapubic body tissues. As we get older it is the equivalent of increasing gravity because elasticity and contractile forces decline. So the andwer is pump, pump, pump rather than anti-coagulants. So, thanks to the self-sacrifice of astraonauts we know how dangerous is a sedentary life after one hits 40!
Surely no one wants the cognitive capacity of the popularizer of the standing desk, so legs (ergo abdominal) exercises in my opinion are critical to survival without incapacitation past 40. Running stairs— CAREFULLY SO AS NOT TO CAUSE CARDIAC STRAIN— is the most efficient exercise in terms of effort, time and benefit of all into later life and is so cheap as there are stairs everywhere that are free to use as everyone else is using the elevator. It must however be systematic and well thought through to avoid injury or cardiovascular problems. Treadmills are a waste of time and electricity when something so cheap is so easily available. But one must follow a systematic five days/week schedule so the brain can be fooled on the other two to give you the benefits for what you didn’t do!
Great fair points, however, I live in a rural community wherein the most steps I can find are at our high school (5 steps exactly). Access to these steps is quite limited as one could imagine due to the school session cycles. Just want to point out that steps are not so ‘cheap’ or ‘easily available’ as you may think.
The exercise in company is important, with the social element one of the vital variables (explained by the mirror neuron system)
I can see the rapid decline in my father’s cognitive function the less he moves. Since he was placed in a Nursing Home, his cognitive decline has been massive.
Fascinated by this, I was diagnosed with HSP a rare mnd that affects the lower body. The consultant told me exercise would not help at all but I’m determined to keep trying. This article gives me the confidence that keeping pushing myself will help maintain a little bit of mobility a bit longer.
I had no idea that leg muscles help the nervous system stay healthy. It’s cool that those types of exercises can send the signals to the brain. It’s a good thing that my whole family likes to work out, especially running and things.
your research is very impressive but kindly suggest us some useful exercises to stay away the brain problems ?
How does this relate to a person with stroke? My mother suffered a stroke 6 months ago and the right side of her body is paralyzed. Although she has physical therapy 3 times a week this does not seem to be helping much. I have heard of microcurrent therapies but would like more info on the subject.