The Brain & Exercise
The benefits from within
Typically, we exercise for a number of reasons. Mostly physical reasons such as to lose weight and building muscle, but also for non-physical reasons such as our mental health. We can see the physical benefits quite easily, and many of us can feel and appear better, calm, and de-stressed after exercising.
Less visible, but perhaps even more important, is the profound influence exercise has on the structure of our brains - an influence that can protect and preserve brain health and function throughout life.
Some experts believe that the human brain may depend on regular physical activity to function optimally throughout our lifetime. Here are just a few ways exercise changes the structure of our brain.
Memory
Many studies suggest that exercise can help protect our memory as we age. Even with as little as 30 minutes a day has been shown to prevent the loss of total brain volume (which can lead to lower cognitive function), as well as preventing shrinkage in specific brain regions associated with memory.
One MRI scan study revealed that in older adults, six months of exercise training increases brain volume, while another study showed that shrinkage of the hippocampus in older people can be reversed by regular walking.
This change was accompanied by improved memory function and an increase of the protein brain-derived neutropic factor (BDNF) in the bloodstream.
BDNF is essential for healthy cognitive function due to its roles in cell survival, plasticity and function.
Positive links between exercise, BDNF, and memory have been widely investigated and have been demonstrated in young adults and older people.
Regular physical activity may protect memory in the long term by inducing neurogenesis via BDNF.
Exercise-induced neurogenesis is being actively researched as a potential therapy for conditions, such as Alzheimer’s disease, Parkinson’s disease and depression.
Blood Vessels
The brain is highly dependent on blood flow, receiving approximately 15% of the body’s entire supply - despite being only around 3% of our body’s total mass.
This is because our nervous tissues need a constant supply of oxygen to function and survive. When neurons become more active, blood flow in the region where these neurons are located increases to meet demand. As such, maintaining a healthy brain depends on maintaining a healthy network of blood vessels.
With regular exercise, we see an increase in the growth of new blood vessels in the areas of the brain where neurogenesis occurs. This provides the increased blood supply that supports the development of these new neurons.
Exercise also improves the health and function of existing blood vessels, ensuring that brain tissue consistently receives the blood supply levels to meet its needs and preserve its function.
Finally, regular exercise can prevent, and even treat high blood pressure, which is a risk factor for development of dementia. Exercise works in multiple ways to enhance the health and function of blood vessels in the brain.
Inflammation
With age (as always seems to be the case), normal immune function declines and chronic, low-level inflammation occurs in body organs. This includes the brain, where it increases risk of diseases such as Alzheimer’s disease.
As we age, microglia become less efficient at clearing damage, and less able to prevent disease and inflammation. This means neuroinflammation can occur, impairing brain functions, including memory.
But recently, studies have shown that exercise can transform the microglia in the brain. Exercise was shown to make the microglia more energy efficient and capable of counteracting these neuroinflammatory activities.
Exercise can also modulate neuroinflammation in degenerative conditions like Alzheimer’s disease as well as Multiple Sclerosis (MS). This means that the effects of physical activity on immune function may be an important target for therapy and disease prevention.
So how can we ensure that we’re doing the right kind of exercise, or getting enough of it to protect the brain?
As of yet, there does not seen to be evidence to support the development of guidelines specific for brain health, yet findings to date do suggest that the greatest benefits are to be gained by aerobic exercise, activities such as walking, running, or cycling (where are my triathletes?)
It’s recommended adults get a minimum of 150 minutes per week of moderate intensity aerobic exercise (~21 minutes/day), combined with activities that maintain strength and flexibility, to maintain good general health (cross training for the runners amongst us).
Plenty of research shows us that exercise is beneficial for many aspects of our health, so it’s important to make sure we’re getting enough. We need to be conscious of making time in our day to be active. A reminder to many maybe that a single thirty-minute workout equates to just 2% of our day.
Our brains will thank us for it in years to come.
While in a Covid world, motivation can get the better of us as Covid Fatigue sets in (if not already), but reminding ourselves about these benefits might offer some of us the motivation to keep going with our exercise routines, or even start again.
Always remember WHY you are doing this, as usually that will spur you right back into to keeping active.
Thank you for reading this article. It is my goal to post more frequently about my journey, running as well as how it ties to mental health.
You can also follow my journey on other social media platforms such as Instagram, Facebook, Twitter, and on Strava (especially for the other runners out there).
I am also raising money for The Alzheimer’s Society in the UK. If you would like to donate to this incredible organisation, a donation link can be found here.
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