TIME: Almanac 1990/1990 Time Magazine Compact Almanac, The (1991)(Time).iso/time/111389/11138900.015

Text File | 1990-09-19 | 4KB | 66 lines

HEALTH, Page 90

Take a Walk -- and Live

A new study says even mild exercise can postpone death


    Couch potatoes, your last excuse is gone. You knew you should
be getting into your running shoes and hitting the pavement. After
all, everyone concedes that exercising is one of the best ways to
stave off heart attacks and other health problems. But hard
physical exertion is downright unpleasant, and you -- along with
about 50 million other sedentary Americans -- could be forgiven for
putting it off or avoiding it altogether.

    No more, though. A study published last week in the Journal of
the American Medical Association says that even a minimal amount
of exercise -- a brisk half-hour walk once a day is enough --
confers significant protection not only from cardiovascular disease
and cancers but also against death from a wide range of other
causes. Put plainly, people who exercise just a little bit tend to
live longer.

    The eight-year, 13,344-subject study, carried out by
researchers at the Institute for Aerobics Research in Dallas, is
hardly the first to establish a link between moderate exercise and
longevity. But it is considered especially significant. For one
thing, it includes both men and women, in contrast to earlier,
mostly male surveys. For another, it strengthens the evidence that
exercise can ward off cancer, a relationship discovered only in the
past few years. And, perhaps most important, it is one of the
largest studies ever done that relied on an objective measure of
fitness, not just participants' descriptions of how much they
exercise.

    The researchers measured fitness in a straightforward way: they
put people on a treadmill, set them walking, and periodically
increased first the incline and then the speed of the treadmill
until the walkers could no longer continue. The subjects were
grouped into five different fitness levels based on their
performance and followed for the next eight years.

    At the end of that time, 283 of the participants, all of whom
were in good health at the start of the study, had died. And after
allowing for various other health-affecting factors, including
smoking, age, cholesterol levels, weight, blood pressure and family
history of heart disease, they found that deaths were sharply
higher in the least-fit category than in the second-most-sedentary
group -- more than double for men and almost twice as high for
women.

    In the most-fit groups, which included people in the habit of
running up to 40 miles a week, death rates tended to be lower
still, but the improvement was not so dramatic. In short, says Carl
Caspersen, a physical-activity epidemiologist at the federal
Centers for Disease Control in Atlanta: "You don't have to be a
marathoner to greatly reduce your mortality. After that first jump
in activity, you're not buying that much more reduced risk."

    While this and earlier studies agree on the health benefits of
regular, moderate exercise, no one is sure of the physiological
mechanisms involved. It may be that exercise increases coronary
blood flow, decreases clotting or both, which would limit the
blood-vessel blockages that cause cardiovascular problems. And some
scientists speculate that exercise increases bowel motility, a
factor in avoiding colon cancer. Those questions may be answered
in part by the next phase of the investigation, which is expected
to include more than 40,000 people. Such speculations are literally
academic, though. For the average man or woman, the message is
clear: get moving.