Walking Associated With Lower Stroke Risk in Women
Women who walked two or more
hours a week or who usually walked at a brisk pace (3 miles per hour or
faster) had a significantly lower risk of stroke than women who didn't
walk, according to a large, long-term study reported in Stroke: Journal
of the American Heart Association.
The risks were lower for
total stroke, clot-related (ischemic) stroke and bleeding (hemorrhagic)
stroke, researchers said.
Compared to women who didn't
- Women who usually walked at a
brisk pace had a 37 percent lower risk of any type of stroke and those
who walked two or more hours a week had a 30 percent lower risk of any
type of stroke.
- Women who typically walked at
a brisk pace had a 68 percent lower risk of hemorrhagic stroke and
those who walked two or more hours a week had a 57 percent lower risk
of hemorrhagic stroke.
- Women who usually walked at a
brisk pace had a 25 percent lower risk of ischemic stroke and those who
usually walked more than two hours a week had a 21 percent lower risk
of ischemic stroke -- both "borderline significant," according to
"Physical activity, including
regular walking, is an important modifiable behavior for stroke
prevention," said Jacob R. Sattelmair, M.Sc., lead author and doctoral
candidate in epidemiology at Harvard School of Public Health in Boston,
Mass. "Physical activity is essential to promoting cardiovascular
health and reducing risk of cardiovascular disease, and walking is one
way of achieving physical activity."
More physically active people
generally have a lower risk of stroke than the least active, with
more-active persons having a 25 percent to 30 percent lower risk for
all strokes, according to previous studies.
"Though the exact
relationship among different types of physical activity and different
stroke subtypes remains unclear, the results of this specific study
indicate that walking, in particular, is associated with lower risk of
stroke," Sattelmair said.
Researchers followed 39,315
U.S. female health professionals (average age 54, predominantly white)
participating in the Women's Health Study. Every two to three years,
participants reported their leisure-time physical activity during the
past year -- specifically time spent walking orhiking, jogging,
running, biking, doing aerobic exercise/aerobic dance, using exercise
machines, playing tennis/squash/racquetball, swimming, doing yoga and
stretching/toning. No household, occupational activity or sedentary
behaviors were assessed.
They also reported their
usual walking pace as no walking, casual (about 2 mph), normal (2-2.9
mph), brisk (3-3.9 mph) or very brisk (4 mph).
Sattelmair noted that walking
pace can be assessed objectively or in terms of the level of exertion,
using a heart rate monitor, self-perceived exertion, "or a crude
estimate such as the 'talk test' -- wherein, for a brisk pace, you
should be able to talk but not able to sing. If you cannot talk, slow
down a bit. If you can sing, walk a bit faster."
During 11.9 years of
follow-up, 579 women had a stroke (473 were ischemic, 102 were
hemorrhagic and four were of unknown type).
The women who were most
active in their leisure time activities were 17 percent less likely to
have any type of stroke compared to the least-active women.
Researchers didn't find a
link between vigorous activity and reduced stroke risk. The reason is
unclear, but they suspect that too few women reported vigorous activity
in the study to get an accurate picture and/or that moderate-intensity
activity may be more effective at lowering blood pressure as suggested
by some previous research.
Stroke is the third leading
cause of death and a leading cause of serious disability in the United
States, so it's important to identify modifiable risk factors for
primary prevention, Sattelmair said.
An inverse association
between physical activity and stroke risk is consistent across genders.
But there tend to be differences between men and women regarding stroke
risk and physical activity patterns.
"The exact relation between
walking and stroke risk identified in this study is not directly
generalizable to men," Sattelmair said. "In previous studies, the
relation between walking and stroke risk among men has been
The study is limited because
it was observational and physical activity was self-reported. But
strengths are that it was large and long-term with detailed information
on physical activity, he said.
Further study is needed on
more hemorrhagic strokes and with more ethnically diverse women,
The American Heart
Association recommends for substantial health benefits, adults should
do at least 150 minutes a week of moderate-intensity or 75 minutes a
week of vigorous-intensity aerobic physical activity or a combination.
Co-authors are: Tobias Kurth,
M.D., Sc.D.; Julie E. Buring, Sc.D.; and I-Min Lee, M.B.B.S., Sc.D.
The National Institutes of
Health supported the study.
For more information on the
American Heart Association, visit www.americanheart.org.