Postmenopausal African-American women who exercise vigorously for more than two hours a week can reduce their risk of developing breast cancer by 64% compared to women of the same race who are sedentary, according to new research.

Scientists identified 97 African-American breast cancer patients living in the Washington, D.C., area, matching them with 102 women of the same race who had not been diagnosed with the disease.

Participants filled out questionnaires about their exercise routines.

Researchers say postmenopausal women who exercised vigorously more than two hours a week in the past year had a 64% reduced risk of breast cancer, compared to women who didn’t exercise at all.

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