Brain Rules (Updated and Expanded)

He was the same age as Wright.
In fact, most of the residents were. I was
beholding two types of aging. Jim and Frank lived in roughly the same
period of time. But one mind had almost completely withered, seemingly
battered and broken by the aging process, while the other mind remained as
incandescent as a light bulb.
What was the difference in the aging process between men like Jim and
the famous architect? This question has intrigued the research community
for a long time. Attempts to explain these differences led to many important
discoveries. I have grouped them as answers to six questions.
1) Is there one factor that predicts how well you will age?
When research on aging began, this question was a tough one to answer.
Researchers found many variables, stemming from both nature and nurture,
that contributed to someone’s ability to age gracefully. That’s why the
scientific community was both intrigued and cautious when a group of
researchers uncovered a powerful environmental influence. One of the
greatest predictors of successful aging, they found, is the presence or
absence of a sedentary lifestyle.
Put simply, if you are a couch potato, you are more likely to age like
Jim, if you make it to your 80s at all. If you have an active lifestyle, you are
more likely to age like Frank Lloyd Wright—and much more likely to make
it to your 90s. The chief reason for the longer life is that exercise improves
cardiovascular fitness, which in turn reduces the risk for diseases such as
heart attacks and stroke. But researchers wondered why the people who
were aging well also seemed to be more mentally alert. This led to an
obvious second question.

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2) Were they more mentally alert?
Just about every mental test possible was tried. No matter how it was
measured, the answer was consistently yes: A lifetime of exercise results in
a sometimes astonishing elevation in cognitive performance, compared with
those who are sedentary. Exercisers outperform couch potatoes in tests that
measure long-term memory, reasoning, attention, and problem-solving skill.
The same is true of fluid-intelligence tasks, which test the ability to reason
quickly, think abstractly, and improvise off previously learned material in
order to solve a new problem. Essentially, exercise improves a whole host
of abilities prized in the classroom and at work.
What about people who aren’t elderly? Here, the number of studies
done thins out. But in one case, researchers looked at more than 10,000
British civil servants between the ages of 35 and 55, grading their activity
levels as low, medium, or high. Those with low levels of physical activity
were more likely to have poor cognitive performance. Fluid intelligence,
the type that requires improvisatory problem-solving skills, was particularly
hurt by a sedentary lifestyle.
Not every cognitive ability is improved by exercise, however. Short-
term memory, for example, and certain types of reaction times appear to be
unrelated to physical activity. And, while nearly everybody shows some
improvement, the degree varies quite a bit among individuals. It’s one thing
to look at a group of people and note, as early studies did, that those who
exercise are also smarter. It’s another thing to prove that exercise is the
direct cause of the benefits. A more intrusive set of experiments needed to
be done to answer the next question.
3) Can you turn Jim into Frank?
Like producers of a makeover show, researchers found a group of
elderly couch potatoes, measured their brain power, exercised them, and
then reexamined their brain power. The researchers consistently found that
all kinds of mental abilities began to come back online—after as little as
four months of aerobic exercise. A different study looked at school-age
children. Children jogged for 30 minutes two or three times a week. After
12 weeks, their cognitive performance had improved significantly
compared with prejogging levels. When the exercise program was

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withdrawn, the scores plummeted back to their preexperiment levels.
Scientists had found a direct link. Within limits, it does appear that exercise
can turn Jim into Frank, or at least turn Jim into a sharper version of
himself.
As the effects of exercise on cognition became increasingly clear,
scientists asked the question dearest to the couch-potato cohort: