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Dr. Medina’s Brain Rule # 1: Exercise Boosts Brain Power.

Updated: Sep 29, 2021

Brain Rules by John Medina, PhD – Rule #1

Dr. Medina’s Brain Rule # 1: Exercise Boosts Brain Power.

Medina tells of the astounding physical and mental strength of 90 year old Jack LaLanne. Also, he talks about the many elderly in nursing homes who have lost much physical and mental capacity. Contrasting these, Medina showcases the famous architect, Frank Lloyd Wright who in his late 80s remained alert.

Researchers wonder what factors determine how we age. He explores this issue by answering six questions:

1) Is there one factor that predicts how well you will age? Research indicates that an active lifestyle is more likely to lead to a long active life. (p. 13)

2) Did mental function improve with exercise? Studies indicate that while an active lifestyle does not cause a well-functioning brain, there is a definite relationship. (p. 14)

3) Can you reverse the process in a person who is already aging mentally and physically? To some extent, yes. (p. 14-15)

4) What’s the bad news? According to the research, aerobic exercise – 30 minutes -2-3 times a week is optimal even though the exact amount is individual. (p. 15)

5) Can exercise treat brain disorders? Risk for depression, dementia, anxiety and Alzheimer’s reduces with exercise probably it regulates the release of three neurotransmitters (serotonin, dopamine, norepinephrine) that are associated with mental health. Some studies even show that exercise can replace antidepressant medications. (p. 15-17)

6) Are the cognitive blessings of exercise only for the elderly? While there are fewer studies on younger populations, those that have been done indicate that active children learn better. (p. 17-18)

Medina provides a detailed explanation of the digestive system and how it provides oxygen to the brain. In short, “Physical activity is cognitive candy.” (p. 22)

Studies show that taking away recess from students reduced academic progress. Adding physical education improved academic achievement. During the school day and the work day, physical activity increases productivity. “Fit employees are capable of mobilizing their God-given IQs better than sedentary employees.” (p. 27)

More information (in video clips) and extensive, notated references are available on

Disclaimer: Dr. Medina uses the evolutionary model to explain much of his brain rules. However, what he observes and the studies he talks about can still help those of us who are not evolutionists.


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