TUESDAY, March 21, 2006 (HealthDay News) -- Just in case the message wasn't clear already, exercise helps -- and rarely hurts -- your heart.
A new study has found that sudden cardiac death during exertion is extremely uncommon in women, and perhaps even more uncommon in women who exercise regularly.
And in the same vein, a second study showed that women who are heavier and who exercise less are more likely to have warning signs implicated in the development of cardiovascular disease.
These two studies appear in the March 22/29 issue of the Journal of the American Medical Association, a themed issue on women's health.
The issue also includes a study that found that women have about the same incidence of stable angina -- chest pain because of insufficient blood flow to the heart -- as men. And a fourth study found that low-dose aspirin therapy is even more protective in women than in men.
Current guidelines recommend that healthy adults engage in at least 30 minutes or more of moderate-intensity physical activity almost daily.
A previous study, however, had showed a certain risk associated with exercise, namely a risk of cardiac death in men.
"That concerned everybody, even though it was very low," said Dr. Alison Schecter, co-director of the Women's CARE (Cardiac Assessment and Risk Evaluation) Center at Mount Sinai Medical Center in New York City. "Should I run a marathon? Should I not run a marathon?" And little research had investigated the issue in women.
The first new study used data from the Nurses' Health Study, which followed 69,693 women without preexisting cardiovascular disease for up to 28 years and reported results related to sudden cardiac death.
As it turned out, the absolute risk of sudden cardiac death associated with moderate to vigorous exertion was one per 36.5 million hours of exertion, which was only slightly more than the risk associated with lesser or no exertion. The risk was even lower among women who exercised regularly. This rate of risk is even lower than that found in men.
"The risks were very, very low, even lower than in men," said study senior author Dr. Christine Albert, director of the Center for Arrhythmia Prevention at Brigham and Women's Hospital in Boston. "Overall, the women who were exercising regularly had a lower risk of sudden cardiac death during all times, not just during exertion."
Schechter said, "While the risk was low in men, it's even lower in women. This gives women the wherewithal to do vigorous exercise and emphasizes how safe it is."
"The benefit of long-term habitual exercise is that you live longer. That can't be underestimated," she added.
Anybody who has been ill or who already has cardiovascular disease should consult their doctor before starting an exercise program, Schechter advised. And being a weekend warrior is not a good way to exercise, she said.
Albert said: "The take-home message is that the risks are low but that there's an intelligent way to begin exercising, which is to build up slowly rather than to go out and do something vigorous when you haven't been exercising at all. It's also important to consult a physician to see if there's any reason you shouldn't exercise. Overall, exercise has multiple health benefits and these benefits certainly outweigh the small risk."
For the second study, an analysis of 27,158 participants in the Women's Health Study, researchers found that less-active women who also had a higher body mass index (BMI, a ratio of weigh to height) showed higher levels of inflammatory and lipid markers that could spell trouble for later heart disease.
"There was an idea that being a little overweight was OK," Schechter said. "Now it seems your BMI should be in a certain range and you should ask your doctor what the ideal BMI is. If it's higher, it impairs your health. The bottom line is that losing weight is good, if you're overweight."
In the third study, medical records of women aged 45 to 89 who had no history of coronary disease revealed that angina strikes women as often as it does men. Previous research had showed that women with angina had a higher risk of coronary death compared with women with no angina.
The final study delivered more good news: Low-dose aspirin therapy, as a way to prevent heart disease, actually worked better in women than in men. The trial participants, 571 men and 711 women, took 81 milligrams of aspirin a day.
The American Heart Association has more on women and heart disease.