http://ap.google.com/article/ALeqM5gGjUYGd7Y2PqRKwz5XmJkvPfIGBgD90B2R580
Exercise-heart study casts doubt on 'fit but fat' theory
By LINDSEY TANNER – 1 day ago
CHICAGO (AP) — New research challenges the notion that you can be fat and
fit, finding that being active can lower but not eliminate heart risks
faced by heavy women. "It doesn't take away the risk entirely. Weight still
matters," said Dr. Martha Gulati, a heart specialist at Northwestern
Memorial Hospital.
Previous research has gone back and forth on whether exercise or weight has
a greater influence on heart disease risks.
The new study involving nearly 39,000 women helps sort out the combined
effects of physical activity and body mass on women's chances of developing
heart disease, said Gulati, who wasn't involved in the research.
The study by Harvard-affiliated researchers appears in Monday's Archives of
Internal Medicine.
Participants were women aged 54 on average who filled out a questionnaire
at the study's start detailing their height, weight and amount of weekly
physical activity in the past year, including walking, jogging, bicycling
and swimming. They were then tracked for about 11 years. Overall 948 women
developed heart disease.
Women were considered active if they followed government-recommended
guidelines and got at least 30 minutes of moderate activity most days of
the week, including brisk walking or jogging. Women who got less exercise
than that were considered inactive.
Weight was evaluated by body mass index: A BMI between 25 and 29 is
considered overweight, while obese is 30 and higher.
Compared with normal-weight active women, the risk for developing heart
disease was 54 percent higher in overweight active women and 87 percent
higher in obese active women. By contrast, it was 88 percent higher in
overweight inactive women; and 2 1/2 times greater in obese inactive women.
About two in five U.S. women at age 50 will eventually develop heart
attacks or other cardiovascular problems. Excess weight can raise those
odds in many ways, including by increasing blood pressure and risks for
diabetes, and by worsening cholesterol. Exercise counteracts all three.
"It is reassuring to see that physical activity really does make an
impact," said lead author Dr. Amy Weinstein of Boston's Beth Israel
Deaconess Medical Center. However, she added, "If you're overweight or
obese, you can't really get back to that lower risk entirely with just
physical activity alone."
University of South Carolina obesity expert Steven Blair, a leading
proponent of the "fit and fat" theory, said the study is limited by relying
on women's self-reporting their activity levels. That method is not as
reliable as a more objective fitness evaluation including exercise
treadmill tests, Blair said. These tests include heart-rate measures to see
how the heart responds to and tolerates exercise.
In Blair's research, overweight people deemed 'fit' by treadmill tests did
not face increased risks of dying from heart disease.
Dr. Laura Concannon, who specializes in treating overweight patients at
Chicago's Advocate Illinois Masonic Medical Center, said the study's
message that exercise can help reduce health risks isn't new, but it's
important.
"Anything that can motivate the public is useful because heart disease is
becoming a bigger and bigger problem as levels of obesity increase,"
Concannon said.