By Lisa Rapaport

(Reuters Health) – Older women who exercise may be less likely to develop heart failure, a U.S. study suggests.

Researchers examined data on 137,303 postmenopausal women, ages 50 to 79 (average age, 63). More than one third had high blood pressure, but few had other risk factors for heart disease like diabetes or a current smoking habit.

After an average of 14 years, 2,523 women developed heart failure. Compared to women who didn’t exercise at all, those who got at least some physical activity were 11 percent less likely to develop heart failure. Participants with the highest activity levels were 35 percent less likely to develop heart failure.

“Our findings show clearly that higher amounts of self-reported total physical activity are associated with significantly lower risks of developing overall heart failure and each subtype,” said lead study author Michael LaMonte, a researcher at the University at Buffalo, New York.

In heart failure, the heart muscle is too weak to pump enough blood through the body. Symptoms include fatigue, weight gain from fluid retention, shortness of breath and coughing or wheezing. Medications can help strengthen the heart and minimize fluid buildup.

Among the women who developed heart failure, 451 had a subtype characterized by what’s known as reduced ejection fraction, which typically occurs after a heart attack and has a worse prognosis. Compared to women who didn’t exercise, those who got at least a little activity were 19 percent less likely to develop this kind of heart failure. Women who exercised the most were 32 percent less likely to develop this subtype.

Another 734 women with heart failure had a subtype characterized by what’s known as preserved ejection fraction. This is more common in older adults and easier to treat. Compared to sedentary women, participants who got a little exercise were 7 percent less likely to develop this kind of heart failure, and women who got the most exercise were 33 percent less likely to develop this subtype.

Walking – the most common leisure activity among older adults – appeared to work just as well as more vigorous workouts, LaMonte said by email.

“This is a big finding,” LaMonte said. “Most adults are able to perform walking activities throughout the day, and often do so as part of usual activities of daily living without necessarily having planned walking as part of an exercise routine.”

To assess activity levels, researchers examined data from exercise questionnaires completed by all of the women. Then, they scored participants’ exercise levels and intensity based on a measure known as metabolic equivalent of task (MET) hours per week.

Women got an average of 13 MET hours per week. Walking was the most common form of exercise, accounting for about 38 percent of participants’ physical activity.

Each additional MET hour of activity per week was tied to a 16 percent lower risk of heart failure overall and a 10 percent lower risk of heart failure with reduced ejection fraction, the researchers report in the Journal of the American College of Cardiology: Heart Failure.

The study wasn’t designed to prove whether or how exercise might directly prevent heart failure. Researchers also depended on women to accurately report their own activity levels, which isn’t always reliable.

Still, the results should serve as a reminder that it’s never too late to start exercising, said Trine Moholdt, a researcher at the Norwegian University of Science and Technology in Trondheim who wasn’t involved in the study.

“Higher doses of physical activity or exercise are more protective, but every level of physical activity is better than being inactive,” Moholdt said by email.

“Walking is an excellent activity choice for older individuals,” Moholdt added. “I would also recommend older women do some activities to maintain their muscle strength and muscle mass.”

SOURCE: JACC: Heart Failure, online September 5, 2018.