Sure, walking is good for you, but a leisurely perambulation around the neighborhood is not going to give you the same health benefits as a brisk walk. In order for walking to make a difference in life expectancy, older women may need to step up their game, a new study suggests.

A sedentary lifestyle causes about as many deaths as smoking each year. You need to exercise at moderate intensity about 150 minutes a week, or step it up to a more vigorous level 75 minutes a week, according to current guidelines. Strength training at least two days a week is important too.

Women who engaged in brisk walking had a 60 to 70 percent lower risk of death after four years than women who were the least active.

Researchers at Brigham and Women’s Hospital looked at the physical activity of over 16,000 older women for seven days. The women, whose average age was 72, wore an accelerometer that measured their physical activity at least 10 hours a day on at least four of the seven days.

Higher amounts of physical activity, as well as more intense levels of activity, were related to a reduction in the women's risk of death. Women who engaged in brisk walking had a 60 to 70 percent lower risk of death after four years than women who were the least active.

This is one of the first studies to use a newer device that is capable of precise measurements of activity, making the results more accurate than earlier studies relying on self-reports. “This study supports current guidelines for physical activity, such as those from the federal government and the American Heart Association, that emphasize moderate-intensity physical activity. It also adds to existing evidence that can inform upcoming physical activity guidelines over time,” said I-Min Lee, first author of the study, in a statement.

Leisurely walking may be beneficial for other health outcomes that weren’t covered in this research, but it was not associated with a lower rate of death. This study will continue and look at those other health outcomes to search for details of the extent and types of activity that are healthful.

The study is published in Circulation.