From this New York Magazine article Why Running Helps Clear Your Mind -- Science of Us:
Regular exercise improves our ability to think and remember through the creation of new brain cells, a process known as neurogenesis.
From this NY Times article, How Testosterone May Alter the Brain After Exercise:
“A new study found that male sex hormones surge in the brain after exercise and could be helping to remodel the mind”.
They tested to see if rats produce the testosterone in the brain by shutting off production in the testes (castration). Further, some of the animals also were injected with a drug that negated the effects of testosterone produced by the brain. Some rats were not altered. They were then divided into groups, sedentary and active rats. The active rats exercise on treadmills for two weeks; the sedentary rats played video games (not really).
Quote from the article:
In a study two groups took a memory quiz. Then one group cycled to exhaustion in 30 minutes and the other group sat there. Their memories were then retested. The result:
“The exercised volunteers performed significantly better on the memory test than they had on their first try, while the volunteers who had rested did not
improve” – quote from the NY Times article How Exercise Benefits The Brain.
They also took blood samples throughout the experiment. They found that: “The cyclists had significantly higher levels of a protein known as brain-derived neurotrophic factor, or BDNF, which is known to promote the health of nerve cells. The men who had sat quietly showed no comparable change in BDNF levels.”
From the article Get Moving for a Health Brain in the September 2013 AARP Bulletin these quotes:
The latest research shows that cognitive decline is not inevitable…the brain continues to make new neurons and fine tune neural connections as we live…Aerobic exercise jumps-tarts that process and slashes your lifetime risk of Alzheimer’s’ in half and general dementia by 60 %.
Exercise boosts the flow of blood to the brain, spurring the release of what has been dubbed Miracle-Gro for the brain – brain-derived neurotrophic factor (BDNF). This chemical stimulates the formation of new neurons in the hippocampus, the area involved in memory, learning and the ability to plan and make decisions. BDNF also repairs cell damage and strengthens
From this study, Effects of aerobic exercise on mild cognitive impairment: a controlled trial this quote:
“Six months of high-intensity aerobic exercise had sex-specific effects on cognition… aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor.”
The sixteen men in the study did not achieve the same positive cognitive results. They postulated that the difference was possibly because the body's use of and production of cortisol, insulin, and glucose differed in women and men. Regardless, the long list of positive changes resulting for high intensity exercise makes it worth the investment of one’s time.
“There’s a lot of hype in this field in terms of brain improvement. I did set out to find out what actually works and what we know. What we do with our bodies has a huge impact on our brains. Our brains are more like our hearts in that everything you do for your heart is thought to be equally as good or better for your brain. Exercise is the best studied thing you can do to your brain. It increases brain volume, produces new baby brain cells in grownup brains. Even when our muscles contract, it produces growth chemicals. Using your body can help your brain.” From the NYT article, The Talents of a Middle-Aged Brain.
A strong body and a strong mind can be obtained through exercise. Prior blog entries dealing with cognitive decline and exercise: