By Seth Baird
Running may be the best medicine to reduce the risk of cognitive decline as we age, and science has caught up. Physical activity throughout the lifespan is one of the most prominent markers for limiting and reducing plaque buildup in the brain, often leading to mild cognitive impairment, a precursor for Alzheimer's. This plaque buildup in the brain limits neurons' ability to communicate with one another, disrupting thought patterns and motor neurons' ability to control gross motor movements such as walking, running, or climbing stairs.
During training, the increase in blood flow, especially to the brain, helps limit the development of this brain-damaging plaque. In other words, runners are priming themselves to age well.
"More than 6 million Americans are living with Alzheimer's. By 2050, this number is projected to rise to nearly 13 million." Alzheimer's Association
What Affect Does Running Have on The Brain?
Research has shown that the brain has the ability to change structurally related to exercise as a stimulus. A 12-month study demonstrated that aerobic walking increased gray matter volume in the brain, which improved cognitive function in older adults. In contrast, it took just ten days of inactivity to see a reduction in cognitive performance. Runners averaging 150 minutes (the CDC's recommendation of weekly exercise) of training a week in addition to strength training to support their endurance goals significantly promote gray matter development and reduce inflammation within the brain.
What is Gray Matter?
Gray matter provides insulation for the neural cell bodies, axons, and dendrites. In addition, gray matter also supports all nerve synapses or locations where one cell communicates with another.
When we run, the increased blood flow promotes perfusion within the brain, which helps enrich the gray matter making it more viable. As we age, a natural decline in gray matter may occur. Reduced gray matter can inhibit cells' ability to communicate with one another. In excess, reduced gray matter leads to cognitive decline and potential delays in motor functioning. Through physical activity, we hope to change the trajectory of this decline.
"Baseline levels of inflammatory biomarkers tend to increase with age, and higher levels of inflammation have been shown to negatively affect cognitive processes, including memory, speed of processing, and global cognitive function." ~ NIH (The Impact of Inflammation on Cognitive Function in Older Adults)
Running helps reduce the buildup of inflammation within the Brain.
While in some circumstances, inflammation in the body can be a good thing, within the brain, increased inflammation can cause brain damage and destroy brain cells. In the long run, this inflammation may increase age-related cognitive decline. Training activates neuroplasticity within the brain, which increases metabolic efficiency, and aids in antioxidative capacity. Neuroplasticity is the brain's ability to adapt and change throughout life, related to a stimulus. When an individual begins running, they start altering their unique gene expression, through neuroplasticity, for the better to one that promotes cognitive longevity and brain health.
What happens to the Brain after you run?
After bouts of moderate training, some positive changes within gray matter include:
Synaptogenesis – the development of synapse formation (the location in which one neuron communicates with another), the maintenance and stabilization of these connection points, and the activity-dependent refinement of these locations.
Angiogenesis – the formation of new blood vessels from pre-existing blood vessels, which helps promote blood flow throughout the brain and vital body organs.
Neurogenesis – is the process in which new neurons are formed within the brain.
Along with increases in cell size and an increase in interstitial fluid or blood flow, running is a great way to promote healthy brain function. In addition to these structural and functional changes in the brain, regular training also leads to behavioral and socioemotional changes as well which support cognitive performance.
Running for Brain Health and Mental Wellbeing
Now that we've touched on the structural benefits of running for the brain, it's important to understand the benefits of reducing anxiety and depression related to regular training as they are a potential precursor for Alzheimer's and dementia.
In the United States, mental health problems account for a large portion of hospitalizations and medical costs each year. Through exercise, and more specifically exercise or training completed within 30% to 70% of maximum heart rate (easy pace mileage), appear to show the most significant impact and reduction in postexercise state anxiety. Furthermore, these effects may last as long as 24 hours following activity. While relaxation techniques such as meditation have similar results, the benefits from training last far longer than the sedentary alternative.
Generally, it's best to participate in training sessions of at least 30 minutes to maximize effects. These acute effects on anxiety are shown to reduce symptoms for "male or female, fit or unfit, active or inactive, anxious or nonanxious, healthy or nonhealthy, younger or older, patients with or without anxiety disorders," furthermore supporting the benefits of the 'runner' lifestyle.
Depression, similar to anxiety, may also be reduced through exercise and training due to the stabilizing hormone cortisol. Cortisol actively works to reduce anxiety, depression, nerve-related problems, and digestive issues. Cortisol helps to improve a weakened immune system, stabilize blood pressure and heart rate, and regulate blood sugar.
While severe depression typically requires treatment, mild symptoms of depression and anxiety can be impacted by regular training 3 - 5 times a week for at least 30 minutes.
Running to Maintain Executive Function Skills
Executive functioning is higher-level cognitive skills that take place in the prefrontal cortex of the brain. This area of the brain allows us to problem-solve, communicate, and adapt to the ever-changing dynamic of life. Aerobic activity plays a significant role in maintaining vitality and healthy brain function.
By nature, avid runners are already taking a proactive approach to their health, but often the cognitive benefits of exercise aren't considered until it's become a problem. In most cases, signs of cognitive decline may present far earlier than the first outward notable symptom. Early intervention through lifestyle changes and maintaining activity levels have now proved to be one of the most effective interventions for reducing the climbing rates of Alzheimer's and dementia diagnosis in the US.
1. Knab, Amy, "Exercise and Brain Health" The Ivey-Brain Health Solutions
3. Sartori C, Andrea "The Impact of Inflammation on Cognitive Function in Older Adults" J Neurosci Nurs. Author manuscript; available in PMC 2013 Aug 1. Published in final edited form as: J Neurosci Nurs. 2012 Aug; 44(4): 206–217. doi: 10.1097/JNN.0b013e3182527690