Women walking at an average or fast pace showed a 26 and 38 per cent lower risk of heart failure.
Brisk walking for at least 40 minutes several times every week may significantly reduce the risk of heart failure among older women, a study has found.
The benefit appears to be consistent regardless of a woman's body weight or whether she engages in other forms of exercise besides walking, researchers said.
About 6.5 million adults have heart failure, a condition in which the heart becomes too weak to pump enough blood to meet the body's needs.
The risk of heart failure rises with age; women 75-84 years of age are three times as likely to have heart failure compared with women 65-74 years old.
"We already know that physical activity lowers the risk of heart failure, but there may be a misconception that simply walking isn't enough," said Somwail Rasla, who conducted the study while at Brown University in the US.
"Our analysis shows walking is not only an accessible form of exercise but almost equal to all different types of exercise that have been studied before in terms of lowering heart failure risk," said Rasla.
"Essentially, we can reach a comparable energetic expenditure through walking that we gain from other types of physical activity," he said.
Since walking can be done any time and does not require special equipment, the results put meaningful physical activity within reach for older women who may be hesitant to join a gym or begin a new workout routine.
The study, which analysed walking behaviour and health outcomes among 89,000 women over a more than 10-year period, is the first to examine, in detail, the benefits of walking by parsing the effects of walking frequency, duration and speed.
It is also the first to specifically focus on the risk of heart failure among women over age 50.
Researcher extracted data for women who, at baseline, were able to walk at least one block and did not have heart failure, coronary artery disease or cancer.
Based on information from participant questionnaires, the women's walking behaviour was categorised according to frequency, duration and speed.
Researchers also assessed the women's overall energy expenditure from walking by combining all three of these variables into a calculation known as Metabolic Equivalent of Task (MET).
Those in the highest tertile for MET per week were 25 per cent less likely to develop heart failure compared with those in the lowest tertile.
The findings suggest walking frequency, duration and speed each contribute about equally to this overall benefit.
Women who walked at least twice a week had a 20 to 25 per cent lower risk of heart failure than those who walked less frequently.
Those who walked for 40 minutes or more at a time had a 21 to 25 percent lower risk than those taking shorter walks.
Women walking at an average or fast pace showed a 26 and 38 per cent lower risk of heart failure, respectively, compared with women who walked at a casual pace.
Researchers said the results were consistent across different age categories, ethnicities and baseline body weight in post-menopausal women, suggesting the findings can be generalised to apply to most women above 50 years old.
"We actually looked at women with four different categories of body mass index (BMI) and found the same inverse relationship between walking behaviour and the risk of heart failure," Rasla said.