There is a lot of emphasis on how exercise impacts body composition. We hear about the effects of exercise on mental health, but very little compared to cutting, toning, and defining. So, how does exercise benefit our brains, why don’t we hear more about it, and what can we do to maximize those benefits?
History of the Mind-Body Connection
Until the Renaissance, the mind and body were viewed as a unified mechanism. In the 17th century, a philosopher named Rene Descartes proposed a theory that separated the two components. This theory, called “Cartesian Dualism”, became the accepted understanding of human health and anatomy. Cartesian Dualism became the basis of scientific understanding in Western Medicine, which dominantly dismissed the symbiotic relationship between the mind and body.
This huge mistake was rectified by several studies examining the connection between the two. Today, scientific inquiry has established evidence leading to the now commonly accepted biopsychosocial model. This model supports the effects of mental and emotional well-being on physical health and vice versa.
Establishing the Connection
It’s important to note that studies conducted regarding brain function in relation to physical activity have focused dominantly on aerobic exercise. Aerobic exercise includes activities like running, swimming, cycling, and rowing. This type of workout accelerates heart rate, increasing blood flow to the brain.
This increased blood flow elevates the production of growth factors, like the Brain-Derived Neurotrophic Factor (BDNF), which protects and creates neurons. While it collaborates with other factors and serves many remarkable purposes, BDNF significantly impacts the hippocampus. The hippocampus is the area of the brain concerned with memory storage and recall, learning, and spatial navigation.
Supporting Studies and Empirical Evidence
Several studies have linked exercise to enhanced brain health.
Naperville Central High School
A Naperville Central High School teacher instituted a revolutionary physical education model called Zero Hour Physical Education. Zero Hour focused on personal student health rather than team activities. Instead, students were encouraged to compete against themselves, focus on personal bests, and were graded according to time spent in target heart rate zones.
Students participating in Zero Hour took the Trends in International Mathematics and Science Study (TIMSS). As a result of the new PE model, Naperville students scored above Singapore, the world’s leading country.
This case study effectively connected aerobic exercise and increased brain function.
British Journal of Sports Medicine
A study published in the British Journal of Sports Medicine examined a group of 70 to 80-year-old women with mild cognitive impairment over the course of six months. This study was the first to show the relationship between exercise, hippocampus volume, and reduced cognitive impairment.
The results of this study indicated that aerobic exercise increases the volume of the hippocampus. Several other factors of the study lead researchers to conclude that aerobic exercise is beneficial for memory and learning and has the potential to impact mild cases of cognitive impairment.
Comprehensive Physiology Study by Fernando and Charles Hillman
A study published in Comprehensive Physiology approached the influence of exercise on cognitive abilities through neuroimaging. Evidence led researchers to conclude that aerobic exercise effectively prevented the loss of neurons due to aging. This result linked metabolic energy processes to synaptic plasticity – the adaptability of how neurons connect with one another.
The Effects of Exercise on the Brain
Aerobic activity improves memory, sharpens focus, enhances mood, and protects against neurodegenerative disorders like Alzheimer’s and Parkinson’s. Some effects take repetitive exposure to BDNF, while others improve immediately following activity.
Improved Memory
There is no shortage of evidence regarding the positive impact of exercise on memory capturing and retention. Exercise enhances the production of new nerve cells and preserves existing ones. Additionally, it strengthens the bonds and pathways between neurons. These functions facilitate signaling and growth factors, advancing the brain’s ability to learn and memorize information.
New information cannot be obtained or submitted to memory during exercise because of its impact on the prefrontal cortex. However, following exercise, blood rushes back to the prefrontal cortex, making it the optimal time to learn. One study showed a 20% increase in the speed of vocabulary memorization following exercise as compared to before.
Sharpened Focus
Exercise serves to sharpen focus through multiple facets. First, exercise fosters the production of Norepinephrine – a neurotransmitter that amplifies signals regarding attention and perception. Secondly, it increases the production of Dopamine – a multipurpose neurotransmitter that improves attention. This transmits signals from the cerebellum – the part of the brain that coordinates thoughts and attention – to the prefrontal cortex. The prefrontal cortex is responsible for organizing mental and physical activity.
Enhanced Mood
Dopamine, Serotonin, and Norepinephrine play a large role in neurotransmission – a type of communication in the body. Not coincidentally, many mood disorders like depression result from decreased activity of these neurotransmitters. Exercise stimulates the release of Dopamine, Serotonin, and Norepinephrine, thereby increasing neural activity and reducing the likelihood and impact of depression.
A study conducted in 1999 resulted in the finding that exercise can be just as effective as medication for mood disorders. However, several factors indicate that exercise is more effective in mood disorder prevention than treatment.
Aging Gracefully
Many mental and physical challenges come naturally with aging. Among those obstacles is neurological degradation. If neurons aren’t used, they die. Studies suggest that 30 minutes of aerobic exercise 4 days per week, performed within 60-65% of max heart rate, is ideal for encouraging neuroplasticity. It’s important to note that aerobic exercise goes beyond prevention because it also repairs deterioration.
Applications
The general recommendation for a healthy individual of any age is to participate in aerobic exercises for 30 minutes to an hour, three or more times per week, within 60-65% of max heart rate. Please consult your doctor if you have any underlying conditions, are elderly, or have questions concerning aerobic activity and your body.
Author’s Note
This article was inspired by “Spark: The Revolutionary New Science of Exercise and the Brain” by John J. Ratey, MD. If you’re interested in learning more about how physical activity impacts brain activity, Dr. Ratey’s book is our recommendation.
