Moderate physical activity lowers heart disease risk in young women
Spending a cumulative 2.5 hours a week doing recreational physical activity is linked with a 25 percent lower risk of coronary heart disease in women under age 50, according to new research in the American Heart Association's journal Circulation.
The benefits of physical activity for cardiovascular health in general have been shown in numerous studies, but most focused on middle-aged and older adults. Although death rates from coronary heart disease are low among women age 25-54, there has been little improvement in these rates in the past 20 years, whereas the rate among older groups has fallen during this period.
"Our reason for carrying out this study was primarily to focus on younger women," said Andrea Chomistek, Sc.D., lead author of the study and assistant professor of epidemiology and biostatistics at the Indiana University School of Public Health-Bloomington. "We wanted to identify steps that young women could take to lower their incidence of coronary heart disease."
Among women age 27-44 at the start of the study, they found:
- women with the highest level of leisure time physical activity were at a 25 percent lower risk incidence of coronary heart disease;
- activity did not have to be strenuous to be beneficial, moderately intense activities such as brisk walking were associated with a lower risk of coronary heart disease;
- the frequency of physical activity did not affect the outcome as long as the total weekly time was at least 150 minutes; andregardless of their body weight when they began, women reduced their coronary heart disease risk by engaging in physical activity.
"Most women can improve their heart health significantly by incorporating some moderate or vigorous physical activity into their regular routine," Chomistek said. "Physical activity appears to be beneficial across the lifespan, regardless of body weight. It's important to remember that any amount of activity is better than none."
Researchers analyzed surveys about the frequency, amount of time, intensity and type of preferred physical activity among more than 97,000 women in the Nurses' Health Study II whose ages at the outset ranged from 27 to 44. In the 20-year follow-up, 544 cases of coronary heart disease were documented.
The study population consisted mostly of white women, so researchers could not necessarily assume the results would apply to men or to other races or ethnicities, Chomistek said. The researchers also noted that because they used surveys to collect their data on physical activity, their results depended on accurate self-reporting.