I am not sure why all this information about physical exercise is coming out right now but there seems to be a continual flow of articles praising the benefits of exercise. Physical exercise has always been acknowledged as a benefit for cardiorespiratory health. Over the past few years there is increasing evidence that physical exercise makes a significant positive impact on our brain. This is very important information because we are facing the challenges of an obesity epidemic, as well as increased numbers in the incidence of Alzheimer’s disease throughout our aging population. Maybe it is the merger between aging, lifestyle and the brain that is influencing continued research.
The Skinny on Physical Exercise and Brain Health
What’s the ‘skinny’ on physical exercise and brain health? As we age we lose brain cells and connections. The volume of our brain decreases. It was previously believed that this result of aging was inevitable. When it was discovered that our brain was capable of changing (neuroplasticity) and growing new cells (neurogenesis) the whole ballgame changed. Technological advances allowed researchers to observe what was actually occurring in the brain as it happened.
The Effects of Exercise Have Impacts on the Brain on Multiple Fronts
And, as it turns out, physical exercise has blown the socks off of researchers as they determined what was going on! The effects of exercise have impacts on the brain on multiple fronts. Aerobic exercise increases heart rate pumping a greater volume of blood to your brain. This is critical to brain health because the brain uses 20% of blood, oxygen and carbohydrates from EVERY heartbeat. The brain is an energy cannibal and requires blood, oxygen and carbs in order to function at a high level. John J. Ratey, a psychiatrist and author of the book – Spark: The Revolutionary New Science of Exercise and the Brain, states that there is overwhelming evidence that exercise produces large cognitive gains and helps fight dementia. “After controlling for age, gender and total brain volume, total minutes of weekly exercise correlated significantly with volume of the right hippocampus. Findings highlight the relationship between regular physical exercise and brain structure during early to middle adulthood.” Exercise also prevents age-related shrinkage of your brain, preserving both gray and white matter in your frontal, temporal, and parietal cortexes, thereby preventing cognitive deterioration. (mercola.com) Similar findings from other studies found that those who engaged in the most physical exercise showed the least amount of shrinkage over a follow-up period of three years. (mercola.com)
Exercise Stimulates BDNF (Brain Derived Neurotropic Factor)
What happens to allow the brain to make new cells and retain brain volume? Exercise stimulates a protein called BDNF (Brain Derived Neurotrophic Factor). BDNF not only preserves existing brain cells but it also activates brain stem cells to convert into new neurons, and makes your brain grow larger. This process has been observed in the hippocampus – center for new learning and memory. Dr. Kirk Erikson’s research confirmed that seniors between the ages of 60 to 80 who walked 30 – 45 minutes, three days per week for one year increased the volume of their hippocampus by two percent. Dr. Erikson states “Generally in this age range, people are losing one to three percent per year of hippocampal volume. The changes in the size of the hippocampus were correlated with changes in the blood levels of the brain-derived neurotrophic factor (BDNF).”
The Nitty-Gritty Benefit of Exercise
Let’s get down to the nitty-gritty of a primary benefit of physical exercise – protection of the brain against cognitive decline in individuals at high risk for dementia – including Alzheimer’s disease. The research we just looked at demonstrated how exercise can slow down aging changes in the brain. But how can exercise protect the brain from dementia? There was a study conducted that included participants who have a high-risk gene for Alzheimer’s, as well as other healthy individuals who don’t have the gene. This study was different from others in that it included individuals who were at high risk for Alzheimer’s disease. Brain activation during memory processing was compared in four separate groups of healthy 65-85 year-old individuals. Risk level was determined on whether they carried the APOE-4 allele. Status of physical activity was based on how often and how much physical activity was reported. The participants were divided into Low Risk/Low Physical Activity, Low Risk/High Physical Activity, High Risk/Low Physical Activity and High Risk/High Physical Activity.
Exercising Increased Brain Activity
fMRI measured brain activation of individuals while performing a mental task which involved discriminating famous people. The sematic memory system is engaged with this test, with activation occurring in 15 different functional brain areas. In participants with the gene, those who exercised showed greater brain activity in memory-related areas compared to sedentary individuals. Individuals with the gene who were physically active had greater brain activity compared to individuals who were not gene carriers and physically active. There are reasons that could explain this finding. For example, individuals with the increased activation could be compensating for an underlying neurological event that’s associated with cognitive decline. Making use of more areas of the brain could provide protection, even in the presence of disease.(AHealthBlog.com)
To sum this all up: Your brain is miraculous. It will be able to handle the deterioration that comes with aging without taking a toll on your memory. “Exercise seems to be preventive in aging and cognitive decline and potentially Alzheimer’s disease as well.” (Dianna Purvis Jaffe PhD)
CNN. (April 29, 2016). How workouts give your brain a boost. Retrieved June 2, 2016 from http://www.brainhealth.utdallas.edu.news_page/how-workouts-give-your-brain-a-boost
A Health Blog. (May 30, 2016). Benefits of regular exercise infographic. Retrieved June 2, 2016 from http://www.ahealthblog.com/benefits-of-regular-exercise-infograph
Mercola,D. (January 23, 2015). The remarkable effects of exercise on cognition and brain cell regeneration. Retrieved May 17, 2016 from http://fitness.mercola.com/sites/fitness/archive/2015/01/23/brain-benefits-exercise.aspx