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Research Highlights
Large trial links fitness to longer life
March 13, 2008
If you need one more reason to start exercising, here it is: A
study involving 15,660 veterans has confirmed that those who
are the fittest tend to live the longest.
The results appeared in the Feb. 2008 issue of Circulation,
published by the American Heart Association. Researchers at
the Palo Alto and Washington, DC, VA medical centers tracked
mortality among 6,749 black and 8,911 white veterans who took
a treadmill test for various reasons, ranging from annual checkstudy ups to complaints of chest pain. The average
age of the men was around 60.
Based on their performance on the exercise
test, the men were grouped into four
relative fitness levels: "low fit," "moderately
fit," "highly fit," and "very highly fit." During
the study’s follow-up period, which extended
as long as 22 years, the death rates in
the four groups, respectively, were 44, 30, 15
and 8 percent. Men in the two fittest groups
were, respectively, 50 and 70 percent less
likely to die than those in the lowest group.
The study’s take-home message, according
to lead author Peter Kokkinos, PhD, is,
"Get out and walk!" He says the peak exercise
workload achieved by the "highly fit"
men was twice that of the "low fit" group
and could be achieved by a brisk walk of
about 30 minutes a day, five or six days a
week. "Walking is the safest and most practical
exercise one can do," says Kokkinos,
who conducts research on cardiovascular
disease at the VA Medical Center in Washington,
DC, and Georgetown University
School of Medicine.
He adds that people should always
check with their physician before starting
any exercise program. The caution sounds
familiar, but the words take on a certain
gravitas coming from Kokkinos: He has
carefully watched thousands of men huff
and puff their way through a stress test,
their bare chests taped with electrodes and
biceps fitted with blood-pressure cuffs, as
he monitors their pressure and checks the
EKG on the computer screen for signs of
blockages in blood flow to the heart, or
abnormal rhythms.
"Exercise represents a stressful condition
for the body—in fact, it is this stress that provides
the impetus for favorable adaptations
by the body," notes the researcher. "However,
the stress imposed by exercise must
not exceed the capacity of the system—in
this case, the body. Although humans have a great capacity to tolerate work, when this
capacity is compromised by heart disease,
inappropriate exercise can cause harm."
Though the results are not surprising, the
study is the largest to date to link longevity
with higher aerobic capacity—as measured
with an actual exercise test, as opposed to
a questionnaire. Moreover, it is the first
large study to evaluate the effects of fitness
in African American men, who are more
at risk for hypertension and other diseases that could conceivably offset the benefits of
exercise.
Kokkinos emphasizes that it isn’t
necessary to run marathons to benefit from
physical activity—only to exercise moderately—and that it’s never too late to start.
He adds that if 30 minutes of walking is too
much to start with, the routine can be split
into 10- or 15-minute sessions in the morning
and evening, and the overall benefits
would be the same.
This article originally appeared in the March 2008 issue of VA Research Currents.
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