I am a certified zealot about the immense value of physical exercise for everything that lives, mostly us. Exercise is good for our hearts, arteries, cholesterol, digestion, metabolism, bones, muscles, sex, etc. In 1982 I wrote an article, "Physical Exercise as an Evolutionary Force," in the Journal of Human Evolution, claiming that our Paleolithic ancestors gave birth to the present edition of us because they were all athletes. In it I claimed that our brains grew because they ran.
For decades I've written and lectured on the many benefits of exercise. But I was always shy about claiming that it was good for our brains because there simply wasn't enough proof for the idea. Then I met Bob Dustman of Salt Lake City. I recruited him several times as a speaker at meetings I was involved in. His article in the obscure journal Neurobiology of Aging in 1984 shocked me. (1) He reported on his research that an exercise program actually improved people's IQs.
Wow! I was stunned and excited!
This report quickly expanded into what is now a fully-credentialed science. This new knowledge was immensely abetted by Carl Cotman's work in 1995 from UC Irvine on BDNF. (2) Huge! BDNF, brain derived neurotrophic factor, is produced in the hypothalamus, and is one of a series of protein molecules that stimulate cellular growth. Most mention of these compounds sadly has to do with their inappropriate exploitation by pro athletes. They improve their performance unquestionably. BDNF is similar except that instead of growing muscles it grows brains.
Guess what stimulates the production of BDNF? Right. You are smart. Exercise stimulates BDNF production. The reigning guru in this effort to display the benefits of exercise on brain health is Arthur Kramer at the University of Illinois. At a recent seminar here at Stanford I had the opportunity to meet and greet and congratulate him on his studies. (3)
With widespread grant support Arthur is rapidly detailing the amazing story of BDNF and its role in human health. His studies pursue a whole range of clinically-based experiments. They employ the latest high-tech instruments to allow insight into how exercise improves brain function. These extend from school kids in their learning curricula to old folks with a whole different agenda confronting them. Importantly, these studies now give underpinning to advisories to patients threatened with neural decay as they age, namely Parkinson's Disease and Alzheimer's Disease. These are prominent targets.
Forty years ago I had no real backing for my intuition that exercise is the magic bullet, the universal panacea. Now even the brain is targeted for both preventive and therapeutic approaches to cognitive decline.
The brain is amazingly plastic. It becomes what it does. Keep moving! Use it or lose it.
And don't forget Bortz's Law: "It is never too late to start, but always too soon to stop."
References:
1) Dustman R. et al Aerobic Exercise Training Improves Neuropsychologic Function of Older Individuals. 1984 Neurobiol. Aging; 5: 35-42.
2) Cotman C., Berchtold H. Exercise and Behavioral Interventions to Enhance Brain Health and Plasticity. Trends Neuroscience 2002; 20:295-301.
3) Chaddock L. et al, Kramer AF. A Functional MRI Investigation Between Childhood Aerobic Fitness and Neurocognitive Control. Biologic Psychology.2012; 89:261-268.