Raleigh, N.C. ? There’s no need to run. Just going for a brisk walk – in the park, around the block or on a treadmill – may be enough to help keep your heart healthy, a small study suggests.

The study, which indicates roughly two to three hours of mild exercise a week at a moderate intensity can significantly cut the risk of cardiovascular disease, supports earlier research.

The findings may encourage people who are reluctant to exercise, said Brian Duscha, the lead author of the research published in the October issue of the journal Chest.

The conclusions are based on a study at Duke University Medical Center of 133 middle-aged overweight sedentary men and women who were at risk for heart disease.

Broken into four groups, the volunteers either did not exercise, walked briskly for 12 miles a week at a moderate intensity, walked briskly or jogged slowly 12 miles a week at a vigorous intensity, or jogged 20 miles a week at a vigorous intensity.

The researchers studied two measurements of fitness – time to exhaustion and oxygen consumption. The better shape a person is in, the more oxygen can be consumed and used, Duscha said.

All the exercise groups saw fitness improvements. And when the two groups that walked 12 miles at differing intensity levels were compared, there wasn’t a significant difference in peak oxygen consumption. There was an improvement for those who jogged vigorously 20 miles a week, an indication that the amount of exercise can be important.

Even if you think you aren’t gaining any benefits because you aren’t losing weight, “don’t stop exercising,” Duscha said.