Walking as Little as Hour a Week Good for Women's Hearts
March 23, 2001 -- (Orlando, Fla.) Take a hike, willya? Or a leisurely stroll. Or try the stairs instead of the elevator. Women who walk as little as about one hour per week have about half the risk of heart disease as women who never get off their, er, sofas, report Harvard University researchers in the Journal of the American Medical Association.
And if that's not enough to get you going, consider this: Overweight women who get some exercise still fare better when it comes to risk factors for heart disease than overweight women who are sedentary. That conclusion comes from a study presented at the annual scientific sessions of the American College of Cardiology here.
In other words, it may be possible to be fat and fit, at least where preventing heart disease is concerned, says C. Noel Bairery Merz, MD, and colleagues from Cedars-Sinai Medical Center in Los Angeles. She and her colleagues found that among overweight women undergoing evaluation for possible coronary heart disease, those who rarely or never performed strenuous activities were more likely to have signs of insulin resistance -- a risk factor for type 2 diabetes and heart problems related to it. In addition, inactive women also had much higher blood levels of triglycerides, a harmful form of fat, than the active women.
"We were interested in evaluating the role of obesity and physical activity, and prior data had suggested that obesity probably is not the true risk factor for heart disease, that it might just be a [sign] for physical inactivity," says Merz, director of preventive cardiology at Cedars-Sinai and associate professor of medicine at the University of California at Los Angeles.
They looked at nearly 700 overweight women whose doctors had ordered angiography, an imaging of the blood vessels supplying the heart, because of a suspicion of coronary artery disease. The women were defined as being overweight if they had a body mass index of 25 or greater, equivalent to being 20% or more above ideal body weight.
Only 14% of the women were considered to be physically active, meaning that during their daily activities -- working, housework, recreation, etc. -- they tended to do things more actively than others, such as taking stairs rather than the elevator.
"When we looked at those 14% -- these are fat ladies but physically active -- they had much lower blockages of their coronary arteries, much lower fasting blood sugars, they had narrower waists, and they had much lower triglycerides, and when we lump those together, that's a bit of the insulin-resistance syndrome," Merz tells WebMD. "These overweight ladies are at risk for insulin resistance and diabetes, but if you're physically active, then the overweight part doesn't turn into insulin resistance."
You don't have to be overweight to see real benefits from even modest exercise, agrees I-Min Lee, MBBS, ScD, associate epidemiologist at Brigham and Women's Hospital and associate professor of medicine at Harvard Medical School in Boston. Lee is the author of the JAMA article.