ease, the apolipoprotein e4 allele, though
not everyone who has the gene develops
Alzheimer’s. Smith found that the brain
function and cognition of more physically
active e4 carriers differ from those of carri-
ers who do not exercise. “Their brain func-
tion and their cognition are protected over
time,” says Smith. “They don’t show de-
cline in cognitive function as much as the
physically inactive e4 carriers.”
Prioritizing brain health is one of the
most impactful ways to ensure you can
achieve your goals as you age, and physical
activity helps regulate brain blood flow. In
people who have been experiencing cogni-
tive decline or have an early diagnosis of Al-
zheimer’s disease, their brains show an in-
creased flow of blood. In this case the brain
is trying to compensate for some of the con-
dition’s neurological tangles and plaques,
but having more blood flow in those cases
is not actually a good thing. Smith found
that physical activity had different effects
for those with a mild diagnosis compared to
those with healthy cognitive function. “We
see increases in people who are cognitively
normal,” says Smith of the brain blood flow.
“But in people who are actually experienc-
ing memory loss, what we see is that exer-
cise reduces their blood flow and actually
helps to normalize it.”
Smith’s team found that the brain’s
decision-making abilities can be affected
by just one workout. “We see that the per-
formance of executive function improves
with a single session of exercise, but also,
the brain networks that are related to this
performance also increased their activa-
tion,” he says. “So all the areas of the brain
that are communicating with one another
in order to perform a task that requires you
to inhibit certain responses to make a deci-
sion when there are competing stimuli that
are distracting you? Those areas are more
likely to have intense activation after ex-
ercise than after doing rest.”
Is there a difference between strength
training and cardio in terms of protecting
your brain for lasting success? Smith says
the best kind of exercise gets you moving
over and over again: “Any physical activity
that’s at least of a moderate intensity that
people enjoy is something that is going to
help them. People should be doing physi-
cal activity as a lifestyle, making it part of
their daily routine.” •△
The brain responds
to stress the way a
muscle responds
to the strain of
exercise. The brain
adapts and becomes
more efficient.